Thèse - Université de Bourgogne
Thèse - Université de Bourgogne
Thèse - Université de Bourgogne
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β4 β4 =<br />
β40 <br />
P0
σ2 = 1
σ2 = 1
µm
T Hz <br />
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GHz
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T Hz <br />
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Chapitre 1<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
GeO2 P2O5
SiCl4 + O2 → SiO2 + 2Cl2<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
o C
a<br />
n c<br />
n g<br />
Gaine<br />
Coeur<br />
<br />
<br />
<br />
µm <br />
<br />
<br />
<br />
<br />
<br />
nc − ng ≈ 0.01 <br />
<br />
SiO2 (∆n = nc − ng) <br />
<br />
∆n <br />
(∆n
λc <br />
λc = 2πan2 c − n2 g<br />
, <br />
2.405<br />
a λc<br />
<br />
λ λc λ > λc<br />
λ λc λ < λc <br />
<br />
λc <br />
a 1.5µm <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
10 −5
10 −4 <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
(n = n(ω)) <br />
<br />
n 2 (ω) = 1 +<br />
m<br />
j<br />
ω 2 j<br />
Bjω 2 j<br />
− ω2 , <br />
ωj Bj <br />
<br />
<br />
<br />
ωj <br />
Bj <br />
<br />
<br />
λj (µm) Bj<br />
1 0.0684043 0.6961663<br />
2 0.1162414 0.4079426<br />
3 9.896161 0.8974794
c/n(ω)<br />
<br />
<br />
β(ω) <br />
ω0 <br />
<br />
β(ω) = n(ω) ω<br />
c = β0 + β1(ω − ω0) + 1<br />
2 β2(ω − ω0) 2 + . . . . . . , <br />
<br />
βm = dmβ dωm , (m = 1, 2, . . .).<br />
ω=ω0<br />
β1 β2 <br />
n <br />
<br />
β1 = 1<br />
<br />
n + ω<br />
c<br />
dn<br />
<br />
=<br />
dω<br />
ng<br />
c<br />
= 1<br />
vg<br />
β2 = 1<br />
<br />
2<br />
c<br />
dn<br />
dω + ω d2n dω2 <br />
= λ<br />
180π<br />
θk =<br />
3<br />
1<br />
=<br />
2(k−1) λj<br />
Bj λ<br />
<br />
λj<br />
1 − λ<br />
√<br />
1 + θ1 + θ2<br />
1+θ1 , <br />
c<br />
θ2(3 − θ2 ) + 4θ3<br />
1+θ1 √ , <br />
1 + θ1<br />
k . <br />
ng vg <br />
β2 d ps nm −1 km −1 <br />
<br />
1 nm 1 km <br />
β2 <br />
β2 = − λ2<br />
d <br />
2πc<br />
β2 <br />
λ <br />
<br />
µm
[ps<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 [ps /km]<br />
2 2 /km]<br />
80<br />
60<br />
40<br />
20<br />
0<br />
-20<br />
-40<br />
-60<br />
-80<br />
>0<br />
2<br />
>0 >0 >0<br />
2<br />
>0<br />
2<br />
λD <br />
λ λD <br />
β2 > 0 λ λD <br />
β2 < 0<br />
<br />
µm <br />
λD <br />
µm λD <br />
<br />
<br />
<br />
µm <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
P0 PL L <br />
<br />
<br />
PL = P0 exp (−αL), <br />
α <br />
αdB dB/km α <br />
αdB = − 10<br />
L<br />
log10( PL<br />
P0<br />
) = 4.343α
(λ < 1.3 µm) <br />
<br />
1/λ 4 <br />
1.3µm 1.5 µm<br />
0.8 µm 0.9 µm <br />
<br />
1.35 µm 1.4 µm OH − <br />
<br />
<br />
1.55 µm <br />
<br />
dB/km <br />
<br />
<br />
Atténuation [dB/Km]<br />
1<br />
0.8<br />
0.6<br />
0.4<br />
0.2<br />
1.1<br />
1.2 1.3 1.4 1.5<br />
Longueur d’on<strong>de</strong> [ μm]<br />
25THz<br />
<br />
λ<br />
1.6
fs<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
n <br />
n(ω, I) = n0(ω) + n2(ω)I, <br />
n0 n2 <br />
I n2 <br />
2.7 × 10 −20 m 2 W −1 <br />
µm <br />
<br />
<br />
<br />
<br />
<br />
µm 2
−→<br />
rot −→ E = − ∂−→ B<br />
, <br />
∂t<br />
−→<br />
rot −→ H = ∂−→ D<br />
, <br />
∂t<br />
div −→ D = 0, <br />
div −→ B = 0, <br />
−→ −→ −→ −→ −→ −→<br />
B = µ0H<br />
D = ε0 E + P E =<br />
−→<br />
E (<br />
−→ −→ −→<br />
r , t) D = D(<br />
−→ −→ −→<br />
r , t) B = B (<br />
−→ −→ −→<br />
r , t) H = H (<br />
−→ −→ −→<br />
r , t) P = P (<br />
−→<br />
r , t) <br />
<br />
<br />
µ0 ε0 <br />
<br />
<br />
−→ P = −→ P L + −→ P NL, <br />
−→ P L −→ P NL <br />
<br />
<br />
∇ 2−→ E − 1<br />
c 2<br />
∂2−→ E<br />
= µ0<br />
∂t2 ∂2−→ P L ∂<br />
+ µ0<br />
∂t2 2−→ P NL<br />
∂t2 .
PNL = ε0<br />
+t<br />
−∞<br />
dt1<br />
t<br />
−∞<br />
dt2<br />
t<br />
−∞<br />
PL = ε0<br />
+t<br />
−∞<br />
χ 1 (t − t ′ )E(r, t ′ )dt ′ , <br />
dt3χ 3 (t−t1, t−t2, t−t3) −→ E ( −→ r , t1) −→ E ( −→ r , t2) −→ E ( −→ r , t3)+. . . ,<br />
<br />
χ 1 χ 3 <br />
<br />
<br />
<br />
<br />
n = n(ω, |E| 2 ) <br />
<br />
χ 3 (t − t1, t − t2, t − t3) = χ 3 xxxxR(t − t1)δ(t − t2)δ(t − t3), <br />
R(t − t1) <br />
<br />
<br />
+∞<br />
−∞<br />
R(t − t1)dt1 = 1. <br />
t > t1 R(t − t1) = 0 <br />
<br />
<br />
<br />
<br />
E = 1 ∧<br />
x[E1(r, t) exp(−iω0t) + c.c.], <br />
2<br />
∧ x E1(r, t) <br />
ω0
P1L = ε0<br />
PL = 1 ∧<br />
x [P1L exp(−iω0t) + c.c.] , <br />
2<br />
PNL = 1 ∧<br />
x [P1NL exp(−iω0t) + c.c.] , <br />
2<br />
+t<br />
χ 1 (t − t ′ )E1(r, t ′ ) exp[−iω0(t ′ − t)]dt ′ + c.c., <br />
−∞<br />
P1NL = 3<br />
4 χ3 +t<br />
xxxxε0E1(r, t)<br />
−∞<br />
R(t − t1) |E1(r, t1)| 2 dt1. <br />
<br />
<br />
<br />
<br />
ε(ω) = 1 + ˜χ 1 + 3<br />
4 χ3 xxxx<br />
∆ ˜ E1 + k 2 ε(ω) ˜ E1 = 0, <br />
k 2 = ω2<br />
, <br />
c2 +t<br />
−∞<br />
R(t − t1) |E1(r, t1)| 2 dt1. <br />
ε ˜ E1 E1<br />
<br />
˜E1(r, ω) =<br />
<br />
+∞<br />
−∞<br />
E1(r, t) exp(iωt)dt. <br />
˜χ 1 χ 1 <br />
ε <br />
<br />
<br />
ε = (ñ + i˜α/2k) 2 .
ε <br />
I =<br />
+t<br />
−∞<br />
ñ = n0 + n2I , <br />
˜α = α + α2I, <br />
R(t − t1) |E1(r, t1)| 2 dt1, <br />
n0, n2 <br />
α, α2 <br />
<br />
<br />
n0 = 1 + Re(˜χ 1 ), <br />
n2 = 3<br />
Re(χ<br />
8n0<br />
3 xxxx), <br />
α = k<br />
Im(˜χ 1 ), <br />
n0<br />
α2 = 3k<br />
Im(χ<br />
4n0<br />
3 xxxx). <br />
n0 α <br />
˜χ 1 <br />
<br />
<br />
˜E1(r, ω − ω0) = CF (x, y) Ã(z, ω − ω0) exp(iβ0z), <br />
C F (x, y) <br />
Ã(z, ω−ω0) <br />
β0 <br />
<br />
C = 1/ (σN)<br />
<br />
σ = ɛ0cn0<br />
2<br />
<br />
et N = |F | 2 dxdy.
F (x, y) <br />
<br />
<br />
∂2F ∂x2 + ∂2F ∂y2 + (k2ε(ω) − ˜ β 2 )F = 0, <br />
∂à ∂z = i( ˜ β − β0) Ã, <br />
˜ β <br />
<br />
<br />
λc <br />
LP01 <br />
<br />
<br />
k 2 ε(ω) = ˜ β 2 . <br />
ɛ <br />
<br />
∆n1 <br />
<br />
<br />
ε = (n0 + ∆n1) 2 ≈ n 2 0 + 2n0∆n1, <br />
∆n1 = i˜α<br />
2k + n2I. <br />
˜β = β(ω) + ∆β(ω), <br />
β(ω) = kn0, <br />
<br />
k∆n1 |F |<br />
∆β(ω) =<br />
2 dxdy<br />
2 . <br />
|F | dxdy<br />
β ω
ω0 <br />
β(ω) = β0 + (ω − ω0)β1 + 1<br />
2 (ω − ω0) 2 β2 + 1<br />
6 (ω − ω0) 3 β3 + 1<br />
24 (ω − ω0) 4 β4 + · · · , <br />
<br />
<br />
βm =<br />
m d β<br />
dω m<br />
β0 ≡ β(ω0), <br />
ω=ω0<br />
∆β <br />
<br />
<br />
(m = 1, 2, · · · ). <br />
∆β(ω) = ∆β0 + (ω − ω0)∆β1 + 1<br />
2 (ω − ω0) 2 ∆β2 + 1<br />
6 (ω − ω0) 3 ∆β3 + · · · , <br />
m d ∆β<br />
∆βm =<br />
dωm <br />
∆β0 ≡ ∆β(ω0) <br />
ω=ω0<br />
(m = 1, 2, · · · ). <br />
A(z, t) <br />
A(z, t) = 1<br />
<br />
2π<br />
<br />
+∞<br />
−∞<br />
Ã(z, ω) exp[−i(ω − ω0)t]dω. <br />
∂<br />
∂t → −i(ω − ω0), <br />
∆β(ω) = ∆β0 <br />
<br />
∂A<br />
∂z +β1<br />
∂A<br />
∂t +iβ2<br />
2<br />
<br />
∂2A −β3<br />
∂t2 6<br />
γ kn2<br />
Aeff<br />
∂3A −iβ4<br />
∂t3 24<br />
∂ 4 A<br />
∂t<br />
4 +α<br />
γ α2<br />
, Aeff =<br />
2Aeff<br />
⎛<br />
A = i(γ+iγ) ⎝A<br />
2<br />
t<br />
−∞<br />
⎞<br />
R(t − t1) |A(z, t1)| 2 dt1⎠<br />
,<br />
<br />
2<br />
2<br />
|F | dxdy<br />
4 <br />
|F | dxdy
γr α ω<br />
<br />
ω0 <br />
<br />
γr(ω) = γ(ω0) + γ1(ω − ω0) + 1<br />
2 γ2(ω − ω0) 2 + 1<br />
6 γ3(ω − ω0) 3 + · · · , <br />
α(ω) = α(ω0) + α10(ω − ω0) + 1<br />
2 α20(ω − ω0) 2 + 1<br />
6 α30(ω − ω0) 3 + · · · , <br />
γm =<br />
m d γ<br />
dω m<br />
ω=ω0<br />
m d α<br />
αm0 =<br />
dωm <br />
ω=ω0<br />
, (m = 1, 2, · · · ). <br />
γr α t ′ = t − t1 <br />
<br />
∂A<br />
∂z<br />
∂A iβ2<br />
+ β1 +<br />
∂t 2<br />
∂2A β3<br />
−<br />
∂t2 6<br />
⎛<br />
<br />
∂<br />
i(γ(ω0) + iγ1 + iγ) ⎝A<br />
∂t<br />
∂ 3 A<br />
iβ4<br />
−<br />
∂t3 24<br />
t<br />
−∞<br />
∂4 <br />
A 1<br />
+<br />
∂t4 2<br />
R(t ′ ) |A(z, t − t ′ )| 2 dt ′<br />
<br />
∂<br />
α(ω0) + iα10 A =<br />
∂t<br />
⎞<br />
⎠ .<br />
<br />
R(t) <br />
R(t)<br />
<br />
R(t) = (1 − fR)δ(t − te) + fRhR(t), <br />
te fR <br />
hR <br />
<br />
hR <br />
<br />
hR(t) = τ 2 1 + τ 2 2<br />
τ1τ 2 2<br />
exp(−t/τ2) sin(t/τ1). <br />
τ1 τ2 <br />
<br />
<br />
|A(z, t − t ′ )| 2 ≈ |A(z, t)| 2 − t ′ ∂<br />
∂t |A(z, t)|2 .
TR ≡<br />
∞<br />
0<br />
tR(t)dt ≈ fR<br />
∞<br />
0<br />
∞<br />
0<br />
thR(t)dt, <br />
R(t)dt = 1, <br />
<br />
<br />
∂A<br />
∂z<br />
∂A iβ2<br />
+ β1 +<br />
∂t 2<br />
iγ|A| 2 A − γs<br />
γ = γ(ω0) + iγi γs = γ(ω0)<br />
ω0<br />
∂2A β3<br />
−<br />
∂t2 6<br />
∂3A iβ4 ∂<br />
−<br />
∂t3 24<br />
4A 1<br />
+<br />
∂t4 2 α(ω0)A =<br />
∂<br />
∂t (|A|2 ∂ |A|2<br />
A) − γRA ,<br />
∂t<br />
<br />
<br />
γR = γ(ω0)TR <br />
<br />
γ γ = γ 0<br />
1+Γ|A| 2 Γ <br />
<br />
<br />
∂A<br />
∂z<br />
∂A iβ2<br />
+ β1 +<br />
∂t 2<br />
∂2A β3<br />
−<br />
∂t2 6<br />
∂3A iβ4<br />
−<br />
∂t3 24<br />
∂4A 1<br />
+<br />
∂t4 2 αA = iγ0 |A| 2 A<br />
2 . <br />
1 + Γ |A|
On<strong>de</strong> continue On<strong>de</strong> modulée<br />
Domaine<br />
temporel<br />
Fibre<br />
Domaine<br />
spectral<br />
0 0<br />
Stokes Anti-Stokes
ω0 <br />
P0 <br />
ω − Ω ω + Ω <br />
P0 − ∆P <br />
<br />
<br />
ks + ka = 2kp. <br />
∆k = ks + ka − 2kp = ∆kL + ∆kNL. <br />
<br />
Ep <br />
Es + Ea = 2Ep, <br />
k <br />
n ω I <br />
<br />
kL = n0 ω<br />
c kNL = n2I ω<br />
c<br />
k = nω<br />
c = (n0 + n2I) ω<br />
, <br />
c<br />
= n2 P<br />
Aeff<br />
ω<br />
<br />
c<br />
<br />
<br />
k = kL + kNL. <br />
Ω <br />
ω0 <br />
kL(ω0 ± Ω) = kL(ω0) ± Ω ∂kL<br />
∂ω<br />
+ 1<br />
2 Ω2 ∂2kL ∂ω<br />
2 ± 1<br />
6 Ω3 ∂3kL ∂ω<br />
3 + 1<br />
24 Ω4 ∂4kL ∂ω<br />
4 + · · · .
ks ka <br />
<br />
ω0 <br />
k L s (ω0 − Ω) = k L p (ω0) − β1Ω + 1<br />
2 β2Ω 2 − 1<br />
6 β3Ω 3 + 1<br />
24 β4Ω 4 + · · · , <br />
k L a (ω0 + Ω) = k L p (ω0) + β1Ω + 1<br />
2 β2Ω 2 + 1<br />
6 β3Ω 3 + 1<br />
24 β4Ω 4 + · · · , <br />
βm = ( ∂kL<br />
∂ω m )ω=ω0, (m = 1, 2, . . .).<br />
<br />
<br />
∆kL = k L s + k L a − 2k L p = β2Ω 2 + 1<br />
12 β4Ω 4 . <br />
<br />
<br />
<br />
<br />
k NL<br />
s = γ(Ps + 2P0 + 2Pa), <br />
k NL<br />
a = γ(Pa + 2P0 + 2Ps), <br />
k NL<br />
p = γ(P0 + 2Ps + 2Pa), <br />
γ = n2ω<br />
Aeff Ps Pa
∆kNL = k NL<br />
s<br />
+ k NL<br />
a<br />
− 2k NL<br />
p = γ(2P0 − Pa − Ps). <br />
<br />
Pa
β2 = 0 , β4 < 0 Ωopt = ( 24γP0<br />
|β4| )1/4<br />
β2 = 0 , β4 > 0 <br />
<br />
2γP0<br />
|β2|<br />
β2 < 0 , β4 = 0 Ωopt =<br />
<br />
β2 < 0 , β4 > 0 si P0 < Pc, Ωopt = Ω0 1 ± 1 − P0<br />
<br />
Pc<br />
β2 < 0 , β4 < 0 Ωopt = Ω0 −1 + 1 + P0<br />
Pc<br />
β2 > 0 , β4 = 0 <br />
β2 > 0 , β4 > 0 <br />
<br />
β2 > 0 , β4 < 0 Ωopt = Ω0 1 + 1 + P0<br />
Pc
Chapitre 2
P0 <br />
L D
(n2)<br />
<br />
<br />
µm
80T eO2 − 20Na2O <br />
As2S3<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
Az = −iβ2<br />
2 Att + β3<br />
6 Attt + iβ4<br />
24 Atttt + iγ |A|2 A αA<br />
2 − , <br />
1 + Γ |A| 2<br />
A(z, t) Aj <br />
A j βm α <br />
Γ = 1/Ps Ps <br />
γ γ = γr + iγi γr <br />
γi <br />
<br />
<br />
<br />
q(z, t) = A(z, t) exp(−αz/2), <br />
qz = −iβ2<br />
2 qtt + β3<br />
6 qttt + iβ4<br />
24 qtttt + iγ exp(−αz) |q|2 q<br />
1 + Γ |q| 2 . <br />
exp(−αz)
Φ ρ <br />
qs = ρ(z) exp[iΦ(z)], <br />
dρ/dz = −γiρ 3 /[1 + Γρ 2 exp(−αz)], <br />
dΦ/dz = γrρ 2 /[1 + Γρ 2 exp(−αz)]. <br />
<br />
<br />
q(z, t) = [ρ + ε(z, t)] exp(iΦ(z)), <br />
|ε(z, t)| 2 ≪ |ρ(z, t)| 2 ε(z, t) <br />
Ω <br />
ε(z, t) = us(z, Ω) exp(iΩt) + ua(z, −Ω) exp(−iΩt), <br />
us(z, Ω) ua(z, −Ω) <br />
<br />
<br />
us(z, Ω) ua(z, −Ω) <br />
<br />
⎡<br />
∂<br />
⎣<br />
∂z<br />
us(z, Ω)<br />
u∗ a(z, −Ω)<br />
⎤<br />
⎦ = iM<br />
⎡<br />
⎣ us(z, Ω)<br />
u ∗ a(z, −Ω)<br />
⎤<br />
⎦ , <br />
u ∗ a ua M <br />
<br />
M =<br />
⎡<br />
⎣ m11 m12<br />
m21 m22<br />
⎤<br />
⎦ ≡<br />
⎡<br />
⎣ Ds(Ω) + iγiP<br />
√ + Q (γr+iγi)P<br />
Q<br />
(−γr+iγi)P<br />
Q<br />
(γr+iγi)P<br />
Q<br />
−Da(Ω) + iγiP<br />
√ Q + (−γr+iγi)P<br />
Q<br />
⎤<br />
⎦ ,
Ds(Ω) = β2<br />
2 Ω2 − β3<br />
6 Ω3 + β4<br />
24 Ω4 , <br />
Da(Ω) = β2<br />
2 Ω2 + β3<br />
6 Ω3 + β4<br />
24 Ω4 , <br />
P = ρ 2 exp(−αz), <br />
Q = [1 + Γρ 2 exp(−αz)] 2 . <br />
<br />
<br />
<br />
<br />
M dz <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
dz <br />
dz <br />
<br />
dz <br />
mij <br />
dz
K <br />
K = − β3<br />
6 Ω3 + iγiP ( 1<br />
<br />
1<br />
+ √ ) ±<br />
Q Q<br />
−γ2 i P 2<br />
Q2 + (β2<br />
2 Ω2 + β4<br />
24 Ω4 + γrP<br />
Q )2 − ( γrP<br />
Q )2 ,<br />
<br />
<br />
<br />
G = ±2 γ2 i P 2Q−2 <br />
β2 − 2 Ω2 + β4<br />
24Ω4 + γrP<br />
2 2 γrP<br />
+ Q<br />
Q<br />
+2γiP (Q −1 + Q −1/2 ).<br />
<br />
<br />
(γi ≪ 1) <br />
<br />
γi <br />
<br />
P0 <br />
<br />
G = 2<br />
γrP1<br />
Q1<br />
P1 P0 exp(−αz) Q1 = (1 + ΓP0 exp(−αz)) 2 <br />
ρ = cte = P0, <br />
2<br />
−<br />
<br />
β2<br />
2 Ω2 + β4<br />
24 Ω4 + γrP1<br />
2 , <br />
Q1<br />
<br />
β2 < 0 β4 > 0 <br />
<br />
G = |β2| Ω 2 |Q2| Ω 2 c exp(−αz)/(Q1Q2Ω 2 ) − 1, <br />
Ω 2 c = 4γrP0/ |β2| Y 2 = |β4| /(12 |β2|) Q2 = 1 − Y 2 Ω 2
P0 ≪ Ps<br />
⇒ P0Γ ≪ 1, ⇒ Q1 ≈ 1 <br />
<br />
G(Ω, z) ≈ |β2| Ω 2 |Q2| Ω 2 c exp(−αz)/(Q2Ω 2 ) − 1. <br />
<br />
(z ≈ 0) exp(−αz) ≈<br />
1 <br />
<br />
<br />
zc = 2α −1 ln(Ωc/Ω) − α −1 ln(1 − Y 2 Ω 2 ). <br />
<br />
<br />
<br />
<br />
<br />
A <br />
q −α <br />
α Ω. <br />
<br />
L <br />
˜G(Ω, L) =<br />
L<br />
0<br />
Ω αL +<br />
L<br />
0<br />
|β2| Ω 2 |Q2|<br />
<br />
Ω 2 c<br />
Ω 2 Q2<br />
exp(−αz) − 1 . <br />
ξ = Ω2c Ω2 <br />
Q2<br />
<br />
L<br />
0<br />
ξ exp(−αz) − 1 =<br />
L<br />
0<br />
ξ exp(−αz)<br />
ξ exp(−αz) − 1 −<br />
L<br />
0<br />
1<br />
ξ exp(−αz) − 1 .
x 2 = ξ exp(−αz) ⇒ dz = −2<br />
dx, <br />
αx<br />
y 2 = x 2 − 1 ⇒ dx =<br />
<br />
<br />
1<br />
ξ exp(−αz) − 1 <br />
<br />
α<br />
<br />
y<br />
y 2 + 1 dy, <br />
y<br />
y2 <br />
dy =<br />
+ 1 α arctan(y)<br />
= <br />
α arctan(ξ exp(−αz) − 1).<br />
<br />
˜GΩ αL + |β2|Ω2 |Q2|<br />
[<br />
α<br />
ξ − 1 − ξ exp(−αL) − 1+<br />
arctan( ξ exp(−αL) − 1) − arctan( ξ − 1)].<br />
L < zc L > zc<br />
<br />
<br />
L > zc [0, zc] <br />
˜G(Ω, L) = −αL + κ W (Ω, 0) − tan −1 (W (Ω, 0)) , <br />
L < zc [0, L] <br />
<br />
<br />
˜G(Ω, L) = −αL + κ η1 + tan −1 (η1/η2) , <br />
κ = α −1 |β2| Ω 2 |Q2| , <br />
W (Ω, x) = [ζ exp(−αx) − 1] 1/2 , <br />
ζ = Ω 2 c/[Ω 2 (1 − Y 2 Ω 2 )], <br />
η1 = W (Ω, 0) − W (Ω, L), <br />
η2 = 1 − W (Ω, 0)W (Ω, L). <br />
<br />
<br />
˜ G(Ω, L) Ω
L > zc <br />
<br />
∂ ˜ GΩ<br />
∂Ω<br />
Ω0 =<br />
<br />
= 0, <br />
6|β2|<br />
, <br />
|β4|<br />
ξ − 1 − 2 arctan( ξ − 1) = 0. <br />
θ = √ ξ − 1 <br />
θ − 2 arctan θ = 0, <br />
θ = 2.331122 θ <br />
<br />
Ω1,2 = Ω0<br />
<br />
1 ± 1/2 1 − P0/P0c , <br />
P0c = 3|β2| 2 (θ 2 +1)<br />
4γr|β4| <br />
L < zc <br />
<br />
Ω0 =<br />
<br />
6|β2|<br />
, <br />
|β4|<br />
exp(−αL)(ξ − 1) − 1 = 0. <br />
ξ <br />
<br />
Ω1,2 = Ω0<br />
<br />
1 ± 1/2 1 − P0/P0cL , <br />
P0cL = 3|β2| 2 (exp(αL)+1)<br />
4γr|β4|<br />
<br />
α
α <br />
<br />
<br />
<br />
<br />
<br />
<br />
z <br />
u ∗ a <br />
d 2 us<br />
dz 2 − [i(m11 + m22) + 1<br />
m12<br />
dm12<br />
dz ]dus<br />
m11 dm12<br />
− [i(dm11 −<br />
dz dz m12 dz )<br />
+(m11m22 − m12m21)]us = 0.<br />
<br />
Γ → 0 γi ≈ 0 β2 < 0 β4 > 0 <br />
β3 = 0 <br />
d2us + αdus + [iα(|β2|<br />
dz2 dz 2 Ω2 − |β4|<br />
24 Ω4 ) + ( |β2|<br />
2 Ω2 − |β4|<br />
24 Ω4 ) 2<br />
−2γrP0 exp(−αz)( |β2|<br />
2 Ω2 − |β4|<br />
24 Ω4 )]us = 0,<br />
<br />
us <br />
<br />
η = √ 8γrP0D10<br />
α<br />
D10 =<br />
x = η exp(−αz/2), <br />
|β2|Ω 2<br />
2 (1 −<br />
|β4|Ω2 ) <br />
12|β2|<br />
x 2 d2us − xdus<br />
dx2 dx − (x2 − µ 2 )us = 0, <br />
µ 2 = 4<br />
α 2 (D 2 10 + iαD10)
us = x r [C0 + C1x + C2x 2 + · · · ] =<br />
∞<br />
Ckx k+r . <br />
<br />
<br />
⎧<br />
⎪⎨<br />
⎪⎩<br />
k=0<br />
[r(r − 1) − r + µ 2 ]C0 = 0<br />
[r(r + 1) − (r + 1) + µ 2 ]C1 = 0<br />
C0 + [(r + 1)(r + 2) − (r + 2) + µ 2 ]C2 = 0<br />
C1 + [(r + 2)(r + 3) − (r + 3) + µ 2 ]C3 = 0<br />
C2 + [(r + 3)(r + 4) − (r + 4) + µ 2 ]C4 = 0<br />
<br />
<br />
C0 = 0 r(r − 1) − r + µ 2 = 0 ⇒ r1,2 = 1 ± 1 − µ 2 <br />
<br />
<br />
r(r − 1) − r + µ 2 = 0<br />
<br />
⎧<br />
⎪⎨<br />
⎪⎩<br />
C2 =<br />
C4 =<br />
C1 = 0,<br />
C0<br />
r(r+2)+µ 2 ,<br />
C3 = 0,<br />
C2<br />
(r+4)(r+2)+µ 2 ,<br />
<br />
<br />
Ci <br />
<br />
ϑ = ± 1 − µ 2 <br />
<br />
C2k = C2k−2<br />
, <br />
2k(2k + ϑ)<br />
C2k = 1<br />
2 k k!<br />
k<br />
m=1<br />
C0<br />
. <br />
(ϑ + 2m)
us = C01<br />
∞<br />
k=1<br />
x 2k+r1<br />
2 k k!<br />
k<br />
m=1<br />
1<br />
+ C02<br />
(ϑ + 2m)<br />
∞<br />
k=1<br />
x 2k+r2<br />
2 k k!<br />
k<br />
m=1<br />
1<br />
, <br />
(ϑ + 2m)<br />
r1 = 1 − ϑ , r2 = 1 + ϑ , <br />
ϑ = 1 − µ 2 C01 C02 <br />
<br />
us(z = 0) = u ∗ a(z = 0) = u0<br />
dus<br />
dz<br />
<br />
<br />
<br />
z=0<br />
= i(m11 + m12)u0.<br />
<br />
<br />
⎧<br />
⎨<br />
⎩<br />
η r1 C01Σ1 + η r2 C02Σ2 = u0,<br />
η r1 C01K1 + η r2 C02K2 = δu0,<br />
K1 = [r1 + d (1)<br />
2 (r1 + 2)η 2 + d (1)<br />
4 (r1 + 4)η 4 + · · · ],<br />
K2 = [r2 + d (2)<br />
2 (r2 + 2)η 2 + d (2)<br />
4 (r2 + 4)η 4 + · · · ],<br />
Σ1 = [1 + d (1)<br />
2 η 2 + d (1)<br />
4 η 4 + · · · ],<br />
Σ2 = [1 + d (2)<br />
2 η 2 + d (2)<br />
4 η 4 + · · · ],<br />
δ = − 2i<br />
α (m11 + m12) = 2i<br />
d (j)<br />
2k =<br />
1<br />
2 k k!C0j<br />
k<br />
m=1<br />
α D10,<br />
1<br />
(ϑ + 2m) .<br />
<br />
C01 = (δΣ2 − K2)u0<br />
η r1(K1Σ2 − K2Σ1) ,<br />
C02 = (K1 − δΣ1)u0<br />
η r2(K1Σ2 − K2Σ1) .
z = L q<br />
<br />
<br />
<br />
g(Ω, L) = <br />
us(L) <br />
<br />
<br />
A <br />
u0<br />
2<br />
, <br />
gA(Ω, L) = g(Ω, L) − α. <br />
<br />
g <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
P0
80T eO2 −<br />
20Na2O<br />
<br />
<br />
⊘ =<br />
474nm<br />
<br />
<br />
<br />
<br />
<br />
As2S3<br />
λ [nm] 1550 1550 1450 490 490 1420<br />
β2[ps 2 m −1 ]<br />
β4[ps 4 m −1 ]<br />
n2[m 2 W −1 ]<br />
−2.9 ×<br />
10 −5<br />
1.7 ×<br />
10 −10<br />
2.6 ×<br />
10 −20<br />
−1.7 ×<br />
10 −4<br />
−2.13 ×<br />
10 −3<br />
−1.22 ×<br />
10 −3<br />
4 × 10 −7 2.09×10 −6 1.28×10 −7<br />
2.6 ×<br />
10 −20<br />
3.8×10 −19 2.6×10 −20<br />
−2.2 ×<br />
10 −2<br />
1.28 ×<br />
10 −7<br />
2.6 ×<br />
10 −20<br />
−2.6 ×<br />
10 −3<br />
9 × 10 −6<br />
2.8 ×<br />
10 −18<br />
α[dB km −1 ] 0.22 25 1000 10000 10000 1000<br />
γr[W −1 m −1 ] 0.0019 0.011 1.52 2.35 2.35 35<br />
P0 [W ] 5 5 0.86 5.5 5.5 0.035<br />
L[m] 400.5 98 8 0.6 0.7 6<br />
D<br />
[GHz m −1 ]<br />
P0 × L × D<br />
[GHz W ]<br />
1.5 3.5 199 9363 1837 187<br />
<br />
<br />
<br />
<br />
<br />
D GHz /m
L D P0 <br />
P LD <br />
P LD = P0 × L × D. <br />
<br />
P0 L P0 <br />
T Hz <br />
<br />
dB
Gain [dB]<br />
Gain [dB]<br />
Gain [dB]<br />
Gain [dB]<br />
30<br />
20<br />
10<br />
0<br />
0 5 10 15<br />
30(a2) Microfibre<br />
en Tellure<br />
20<br />
10<br />
0<br />
10<br />
0<br />
0 20 40 60 80<br />
30 (a4) Nanofibre<br />
Chalcogenure<br />
20<br />
10<br />
0<br />
(a1)<br />
PCF Silice<br />
ESNL<br />
ASLE<br />
ASLA<br />
0 10 20<br />
30 (a3) Taper<br />
SMF28<br />
20<br />
0 5 10 15<br />
[THz]<br />
opt [THz]<br />
opt [THz]<br />
opt [THz]<br />
opt [THz]<br />
4<br />
2<br />
0<br />
20 40 60 80<br />
6 (b2) Microfibre en Tellure<br />
4<br />
15<br />
10<br />
5<br />
6<br />
4<br />
2<br />
0<br />
(b1)<br />
0.1 0.2 0.3 0.4 0.5<br />
Nanofibre<br />
(b4)<br />
Chalcogenure<br />
1 2 3 4 5<br />
z [m]<br />
PCF Silice<br />
ESNL<br />
2<br />
ASLE<br />
ASLA<br />
0<br />
2 4 6<br />
25 Taper SMF28<br />
20<br />
(b3)<br />
SMF28 Altere<br />
Ωopt z
α <br />
γr <br />
<br />
(400 m) <br />
<br />
<br />
<br />
<br />
<br />
(100 m) <br />
<br />
<br />
(60 cm) <br />
<br />
<br />
D = 9363 GHz/m<br />
<br />
<br />
<br />
<br />
<br />
β2 <br />
β2 <br />
(−2.2 × 10 −2 ps 2 m −1 ) D = 1837 GHz/m
P LD <br />
<br />
<br />
<br />
<br />
<br />
dB/m <br />
<br />
<br />
<br />
<br />
mW <br />
mW <br />
<br />
dB/m <br />
P LD<br />
P LD
P LD <br />
<br />
<br />
<br />
<br />
<br />
dB/m <br />
<br />
<br />
<br />
<br />
mW <br />
mW <br />
<br />
dB/m <br />
P LD<br />
P LD
Chapitre 3
Az = −iβ2<br />
2 Att + β3<br />
6 Attt + iβ4<br />
24 Atttt + iγ |A|2 A<br />
2 , <br />
1 + Γ |A|<br />
A(z, t) βm <br />
Γ = 1/Ps Ps <br />
γ
G = 2<br />
<br />
˜γ 2 P 2 0 − ( β2<br />
2 Ω2 + β4<br />
24 Ω4 + ˜γP0) 2 , <br />
P0 ˜γ = γ<br />
Q Q = (1 + ΓP0) 2 dG<br />
dΩ<br />
<br />
= 0 <br />
β2<br />
2 Ω2 + β4<br />
24 Ω4 + ˜γP0 = 0, <br />
β2Ω + β4<br />
6 Ω3 = 0. <br />
<br />
<br />
<br />
Ω1,2 = − 6β2<br />
±<br />
β4<br />
6<br />
<br />
β<br />
β4<br />
2 2 − 2<br />
3 ˜γβ4P0, <br />
<br />
Ω0 =<br />
− 6β2<br />
, <br />
β4<br />
<br />
β2 β4 <br />
<br />
β2 <<br />
0 β4 > 0 <br />
P0c<br />
P0 < P0c <br />
Ωopt± P0 > P0c <br />
Ω0 <br />
β2 β4
β2 = 0 , β4 < 0 Ωopt = ( 24γP0<br />
|β4| )1/4<br />
β2 = 0 , β4 > 0 <br />
β2 < 0 , β4 = 0 Ωopt =<br />
<br />
β2 < 0 , β4 > 0 si P0 < P0c, Ωopt± = Ω0 1 ±<br />
<br />
β2 < 0 , β4 < 0 Ωopt = Ω0<br />
<br />
2γP0<br />
|β2|<br />
1 − P0<br />
P0c ; si P0 > P0c, Ωopt = Ω0<br />
−1 +<br />
β2 > 0 , β4 = 0 <br />
<br />
1 + P0<br />
P0c<br />
β2 > 0 , β4 > 0 <br />
<br />
β2 > 0 , β4 < 0 Ωopt = Ω0 1 + 1 + P0<br />
P0c<br />
<br />
P0c = (3|β2| 2 Q 2 )/(2γ|β4|)<br />
<br />
P0 > P0c P0 <br />
<br />
ξΓ 2 P 2 0 + (2Γξ − 1)P0 + ξ < 0, <br />
3|β2| 2<br />
ξ ≡ 2γ|β4| <br />
<br />
Pc1 Pc2 Pc1 < P0 < Pc2 <br />
Pc1 ≡ 1 − 2Γξ − √ ∆<br />
2ξΓ 2 , <br />
Pc2 ≡ 1 − 2Γξ + √ ∆<br />
2ξΓ 2 , <br />
∆ = 1 − 4Γξ Pc1 Pc2 <br />
∆ ∆ 0 |β4|<br />
<br />
|β4| > β4c ≡ 6|β2| 2Γ . <br />
γ
Ω0 P0 <br />
<br />
<br />
Pc1 < P0 < Pc2, <br />
|β4| > β4c. <br />
<br />
<br />
<br />
Ωopt+ Ωopt− <br />
<br />
<br />
<br />
<br />
<br />
β4 = β4c Pc1 = Pc2 = Ps <br />
Γ → 0 Pc1 ∼ ξ ∝ 1<br />
β4 Pc2 → ∞ <br />
β4c → 0 <br />
<br />
P0 > ξ. <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
Pc1,c2
β4<br />
β<br />
40<br />
β4c<br />
Effets <strong>de</strong>s pertes<br />
P<br />
Réservoir<br />
<strong>de</strong><br />
Photons<br />
(RP)<br />
Remplissage du RP<br />
P<br />
c1<br />
Ω 0<br />
c10 P 0<br />
PS Puissance<br />
I<br />
Ω<br />
P<br />
c2<br />
Ω<br />
II<br />
1 2<br />
β2 < 0 β4 > 0<br />
<br />
<br />
β4cPS β4c β4 <br />
<br />
β4 <br />
<br />
<br />
<br />
<br />
Ω1,2 = Ω0<br />
Ω0 =<br />
<br />
6 |β2|<br />
, <br />
|β4|<br />
<br />
1 ± 1/2 1 − P0/P0cL , si L < zc,
P0cL = 3|β2| 2 (exp(αL)+1)<br />
4γr|β4| P0cL <br />
Ω1,2 <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
P0 Pc1 <br />
<br />
R (z = 0) = P0 − P0cL , <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
R(z = 0) = P0 − Pc1(β2, β4)(e αL + 1)/2
R(z) = P (z) − P0cL = 0 <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
P0 = Pc1(β2, β4) × (exp(αL) + 1)/2. <br />
<br />
<br />
<br />
<br />
β4 β4 = β40<br />
<br />
β2 β40 L <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
L = 6 m α = 1 dB/m γr = 35 W −1 m −1 β2 = −2.6 ps 2 /km
β4 = 9 × 10 −3 ps 4 /km <br />
Pc1 = 33 mW<br />
<br />
L = 6 m <br />
<br />
z <br />
<br />
P0 = 35 mW <br />
Pc1 <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
P0 = 55 mW <br />
Pc1 <br />
<br />
<br />
<br />
<br />
±6.65 T Hz<br />
z 4.2 m <br />
z = 0 z ∼ 4.2 m <br />
<br />
z = 4.2 m
Gain [dB]<br />
opt [THz]<br />
100<br />
80<br />
60<br />
40<br />
20<br />
0<br />
9<br />
8.5<br />
8<br />
7.5<br />
7<br />
6.5<br />
6<br />
5.5<br />
5<br />
4.5<br />
4<br />
Theorie (ASL)<br />
(a1)<br />
55mW<br />
35mW<br />
z=6m<br />
P 0 =0.13W<br />
ASLA<br />
ASLE<br />
0 5 10<br />
[THz]<br />
15<br />
(b1)<br />
ASLA<br />
ASLE<br />
P 0 =35mW<br />
55mW<br />
35mW<br />
0.13W<br />
55mW<br />
3 4 5<br />
z [m]<br />
Simulation (ESNL)<br />
(a2)<br />
z=6m<br />
55mW<br />
35mW<br />
P 0 =0.13W<br />
ESNL<br />
ASLE<br />
0 5 10<br />
[THz]<br />
15<br />
(b2)<br />
P 0 =35mW<br />
ESNL<br />
ASLE<br />
35mW<br />
55mW<br />
55mW<br />
3 4 5<br />
z [m]<br />
0.13W<br />
<br />
P0 = 35 mW P0 = 55<br />
mW P0 = 130 mW
4.2 m <br />
<br />
<br />
P (z) < Pc10 <br />
<br />
<br />
<br />
z ∼ 4.2 m <br />
<br />
<br />
P0 = 130 mW <br />
<br />
<br />
<br />
<br />
<br />
P0 = 0.13 W<br />
z = L = 6 m <br />
<br />
P0 = 35 mW P0 = 55 mW <br />
<br />
<br />
P0 = 0.13 W <br />
<br />
<br />
<br />
<br />
P0
β4 <br />
P0<br />
<br />
β4 <br />
<br />
<br />
<br />
β 4<br />
β 40<br />
β 4c1<br />
β 4c<br />
Effets <strong>de</strong>s pertes<br />
Réservoir<br />
<strong>de</strong><br />
photons<br />
Pc10<br />
P 0<br />
Pc1<br />
Ω 0<br />
Remplissage du RP<br />
Ps<br />
Pc2<br />
Ω 1 Ω 2<br />
Puissance<br />
<br />
β4
R = P0[1 − exp(−αL)]. <br />
<br />
β4c1 β4 P0<br />
<br />
β4 β4c1 Pc1(β4) <br />
P0 <br />
β40 P0 Pc1 <br />
<br />
P0 − P0cL (β40) = R. <br />
<br />
<br />
<br />
β4 = 5 × 10 −6 ps 4 m −1 β4c1 = 5.3 × 10 −6 ps 4 m −1 <br />
<br />
<br />
<br />
<br />
<br />
<br />
β4 β4c1 <br />
β4 = 9 × 10 −6 ps 4 m −1 > β4c1 = 5.3 × 10 −6 ps 4 m −1 <br />
<br />
<br />
<br />
z ∼ 4.2 m <br />
<br />
z = 4.2 m
Gain [dB]<br />
opt [THz]<br />
50<br />
40<br />
30<br />
20<br />
10<br />
0<br />
12<br />
11<br />
10<br />
9<br />
8<br />
7<br />
6<br />
5<br />
(a)<br />
4 =510 -6 ps 4 m -1<br />
ESNL<br />
ASLE<br />
ASLA<br />
0 5 10<br />
[THz]<br />
15<br />
(b)<br />
4 =510 -6<br />
ps 4 m -1<br />
1 2 3 4 5<br />
z [m]<br />
z=6m<br />
ESNL<br />
ASLE<br />
ASLA<br />
<br />
β4 = 5 × 10 −6 ps 4 m −1 P0 = 55 mW <br />
β2 = −2.6 × 10 −3 ps 2 m −1
Gain [dB]<br />
opt [THz]<br />
50<br />
40<br />
30<br />
20<br />
10<br />
0<br />
8.5<br />
8<br />
7.5<br />
7<br />
6.5<br />
6<br />
5.5<br />
5<br />
4.5<br />
(a)<br />
ps 4 m -1<br />
=910<br />
4 -6<br />
ESNL<br />
ASLE<br />
ASLA<br />
0 5 10 15<br />
[THz]<br />
(b)<br />
ps 4 m -1<br />
=9x10<br />
4 -6<br />
ESNL<br />
ASLE<br />
ASLA<br />
3 4<br />
z [m]<br />
5<br />
z=6m<br />
<br />
β4 = 9 × 10 −6<br />
ps 4 m −1 P0 = 55 mW β2 = −2.6 × 10 −3 ps 2 m −1
Gain [dB]<br />
opt [THz]<br />
50<br />
40<br />
30<br />
20<br />
10<br />
0<br />
5.8<br />
5.6<br />
5.4<br />
5.2<br />
5<br />
4.8<br />
4.6<br />
4.4<br />
4.2<br />
4<br />
(a)<br />
4 =15x10 -6<br />
ps 4 m -1<br />
ESNL<br />
ASLE<br />
ASLA<br />
0 5 10<br />
[THz]<br />
15<br />
(b)<br />
4 =15x10 -6<br />
ESNL<br />
ASLE<br />
ASLA<br />
ps 4 m -1<br />
0 1 2 3<br />
z [m]<br />
4 5<br />
z=6m<br />
<br />
β4 = 15 × 10 −6<br />
ps 4 m −1 P0 = 55 mW β2 = −2.6 × 10 −3 ps 2 m −1
Ω0 <br />
Ω0 Ω0+δΩ(z)<br />
Ω0 − δΩ(z)<br />
β4 β4c1 β4 = 15 ×<br />
10 −6 ps 4 m −1 > β4c1 = 5.3 × 10 −6 ps 4 m −1 <br />
L =<br />
6 m <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
α <br />
35 mW <br />
α = 1 dB/m α = 2.4 dB/m
Gain [dB]<br />
Gain [dB]<br />
30 (a)<br />
25<br />
20<br />
15<br />
10<br />
5<br />
0<br />
12<br />
10<br />
8<br />
6<br />
4<br />
2<br />
P 0 =35mW<br />
=1.4<br />
=1.8<br />
=2.4<br />
=1dB m -1<br />
14 (b) =2.4dB m -1 P 0 =50mW<br />
0<br />
0 2 4 6 8 10<br />
[THz]<br />
<br />
<br />
β2 = −2.6 × 10 −3 ps 2 /m β4 = 9 × 10 −6 ps 4 /m<br />
<br />
25 dB α = 1 dB/m 2.5 dB α = 2.4 dB/m
α = 1 dB/m α = 2.4 dB/m
GHz<br />
T Hz
m <br />
T Hz
Chapitre 4
β2 < 0 et β4 > 0 <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
∂Ax<br />
∂z<br />
+ i∆B<br />
2 Ax + iβ2<br />
2<br />
∂2Ax β3<br />
−<br />
∂t2 6<br />
∂ 3 Ax<br />
∂t 3 − iβ4<br />
24<br />
∂ 4 Ax<br />
∂t 4 = iγ[(|Ax| 2 + 2<br />
3 |Ay| 2 )Ax + 1<br />
3 A2 yA ∗ x],
∂Ay<br />
∂z<br />
− i∆B<br />
2 Ay + iβ2<br />
2<br />
∂2Ay β3<br />
−<br />
∂t2 6<br />
∂3Ay iβ4 ∂<br />
−<br />
∂t3 24<br />
4Ay ∂t4 = iγ[(|Ay| 2 + 2<br />
3 |Ax| 2 )Ay + 1<br />
3 A2xA ∗ y],<br />
<br />
x y ∆B<br />
<br />
∆B = 2πB/λ <br />
A 2 yA ∗ x A 2 xA ∗ y <br />
<br />
<br />
A± = 1<br />
√ 2 (Ax ± iAy), <br />
A+ A− <br />
<br />
<br />
∂A+<br />
∂z<br />
∂A−<br />
∂z<br />
+ i∆B<br />
2 A− + iβ2<br />
2<br />
+ i∆B<br />
2 A+ + iβ2<br />
2<br />
∂2A+ β3<br />
−<br />
∂t2 6<br />
∂2A− β3<br />
−<br />
∂t2 6<br />
∂3A+ iβ4<br />
−<br />
∂t3 24<br />
∂3A− iβ4<br />
−<br />
∂t3 24<br />
<br />
∂4A+ 2iγ<br />
=<br />
∂t4 3 (|A+| 2 + 2|A−| 2 )A+, <br />
∂4A− 2iγ<br />
=<br />
∂t4 3 (|A−| 2 + 2|A+| 2 )A−. <br />
<br />
<br />
<br />
Ax0 = √ P exp [i(γP − ∆B<br />
2 )z], Ay0 = 0, <br />
P <br />
<br />
∆B
φ = (γP − ∆B<br />
2 )z<br />
Ax = ( √ P + f) exp [i(γP − ∆B<br />
2 )z] = (√ P + f) exp (iφ), <br />
Ay = g exp [i(γP − ∆B<br />
)z] = g exp (iφ), <br />
2<br />
<br />
A± =<br />
P<br />
2<br />
<br />
f ± ig<br />
+ √<br />
2<br />
exp (iφ). <br />
<br />
<br />
∂f<br />
∂z<br />
+ iβ2<br />
2<br />
∂g<br />
iβ2<br />
− i∆Bg +<br />
∂z 2<br />
∂2f β3<br />
−<br />
∂t2 6<br />
∂2g β3<br />
−<br />
∂t2 6<br />
∂3f iβ4 ∂<br />
−<br />
∂t3 24<br />
4f ∂t4 − iγP (f + f ∗ ) = 0, <br />
∂3g iβ4<br />
−<br />
∂t3 24<br />
∂4g iγP<br />
+<br />
∂t4 3 (g − g∗ ) = 0. <br />
<br />
(f) <br />
(g) <br />
<br />
β4 <br />
Ω <br />
(f) (g) <br />
f = vse iΩt + vae −iΩt , <br />
g = use iΩt + uae −iΩt , <br />
vs va <br />
<br />
us ua
Y <br />
M <br />
<br />
∂Y<br />
∂z<br />
= iMY, <br />
Y T = [vs, v ∗ a, us, u ∗ a], <br />
⎛<br />
⎞<br />
M11<br />
⎜ M21<br />
M = ⎜ 0<br />
⎝<br />
M12<br />
M22<br />
0<br />
0<br />
0<br />
M33<br />
0<br />
0<br />
M34<br />
⎟ ,<br />
⎟<br />
⎠<br />
<br />
0 0 M43 M44<br />
M11 = β2<br />
2 Ω2 − β3<br />
6 Ω3 + β4<br />
24 Ω4 + γP, <br />
M12 = −M21 = γP, <br />
M22 = −β2<br />
2 Ω2 − β3<br />
6 Ω3 − β4<br />
24 Ω4 − γP, <br />
M33 = ∆B + β2<br />
2 Ω2 − β3<br />
6 Ω3 + β4<br />
24 Ω4 − γP<br />
, <br />
3<br />
M34 = −M43 = γP<br />
3<br />
, <br />
M44 = −∆B − β2<br />
2 Ω2 − β3<br />
6 Ω3 − β4<br />
24 Ω4 + γP<br />
. <br />
3<br />
M <br />
<br />
⎛<br />
M =<br />
M// = ⎝ M11 M12<br />
M21 M22<br />
⎛<br />
⎝ M// 0<br />
0 M⊥<br />
⎞<br />
⎠ , et M⊥ =<br />
⎞<br />
⎠ , <br />
⎛<br />
⎝ M33 M34<br />
M43 M44<br />
⎞<br />
⎠ ,
vs, v ∗ a, us, u ∗ a <br />
M// M⊥<br />
K// K⊥ <br />
M// M⊥ <br />
<br />
K⊥ =<br />
K// =<br />
3 β3Ω<br />
6 ±<br />
<br />
( β2Ω2 β4Ω4 +<br />
2 24 + γP )2 − γ2P 2 , <br />
3 β3Ω<br />
6 ±<br />
<br />
β2Ω2 β4Ω4 γP<br />
(∆B + + −<br />
2 24 3 )2 − ( γP<br />
3 )2 . <br />
<br />
<br />
G⊥ = 2Im(K⊥) = 2<br />
<br />
( γP<br />
3 )2 − (∆B +<br />
β2Ω 2<br />
<br />
G// = 2Im(K//) = 2 γ2P 2 β2Ω2 − (<br />
2<br />
2<br />
+ β4Ω 4<br />
24<br />
− γP<br />
3 )2 , <br />
+ β4Ω 4<br />
24 + γP )2 , <br />
Im G// G⊥ <br />
<br />
<br />
∆B G⊥<br />
<br />
<br />
<br />
<br />
<br />
⎧<br />
<br />
⎨ G// = 2<br />
G = <br />
⎩ G⊥ = 2<br />
∂G<br />
∂Ω<br />
= 0, <br />
γ 2 P 2 − ( β2<br />
2 Ω2 + β4<br />
24 Ω4 + γP ) 2 ,<br />
( γP<br />
3 )2 − (∆B + β2<br />
2 Ω2 + β4<br />
24 Ω4 − γP<br />
3 )2 .
Ω//2 =<br />
<br />
Ω//1 =<br />
−6β2<br />
β4<br />
<br />
± 6<br />
β4<br />
−6β2<br />
, et/ou <br />
<br />
<br />
Ω⊥2 =<br />
<br />
−6β2<br />
β4<br />
Ω⊥1 =<br />
β4<br />
β 2 2 − 2<br />
3 γP β4, <br />
<br />
−6β2<br />
, et/ou <br />
β4<br />
± 6<br />
<br />
β<br />
β4<br />
2 2 − 2<br />
3 β4(∆B − γP<br />
), <br />
3<br />
Ω// Ω⊥ <br />
<br />
<br />
<br />
<br />
<br />
<br />
G//<br />
<br />
<br />
<br />
β2 β4 <br />
∆B <br />
<br />
<br />
<br />
σ2 ≡ β2/|β2| σ4 ≡ β4/|β4|
σ2σ4 < 0 <br />
<br />
<br />
<br />
<br />
<br />
σ2 = 1<br />
<br />
<br />
<br />
<br />
σ4 <br />
σ4 = 0<br />
<br />
<br />
<br />
β4 = 0 <br />
Ωopt =<br />
<br />
2 γP<br />
( |β2| 3<br />
− ∆B)<br />
∆B > 0 <br />
<br />
Ωopt =<br />
<br />
|∆B|(p − 2)<br />
, (p > 2). <br />
|β2|<br />
p = P<br />
Pc Pc = 3|∆B|<br />
<br />
2γ<br />
P <br />
pl = 2
|β2| → 0 |Ωopt| →<br />
∞ <br />
<br />
<br />
∆B < 0 <br />
<br />
<br />
<br />
<br />
<br />
Ωopt =<br />
|∆B|(p + 2)<br />
.<br />
|β2|<br />
<br />
<br />
<br />
β2 0 <br />
<br />
|β2| → 0 |Ωopt| → ∞ <br />
<br />
<br />
<br />
<br />
|Ωopt| → ∞ |β2| → 0 <br />
<br />
<br />
<br />
<br />
<br />
β4 <br />
<br />
σ4 = 1
∆B > 0 ∆B < 0<br />
∆B > 0 <br />
<br />
<br />
<br />
<br />
<br />
Ω =<br />
6|β2|<br />
−<br />
|β4|<br />
<br />
6|β2|<br />
+ 1 +<br />
|β4|<br />
2 |β4|<br />
(γP<br />
3 |β2| 2 3<br />
− ∆B). <br />
p = P<br />
Pc Pc = 3|∆B|<br />
<br />
2γ<br />
<br />
<br />
<br />
<br />
Ω =<br />
6|β2|<br />
−<br />
|β4|<br />
6|β2|<br />
+<br />
|β4|<br />
<br />
1 + |β4|∆B<br />
(p − 2).<br />
3|β2| 2 <br />
<br />
p > 2 <br />
Ωopt = Ω0<br />
<br />
<br />
<br />
<br />
−1 + 1 + ∆B|β4|(p − 2)<br />
3|β2| 2 , <br />
<br />
6|β2|<br />
Ω0 = |β4| <br />
|β2| → 0 <br />
<br />
<br />
<br />
<br />
Ω =<br />
6|β2|<br />
−<br />
|β4|<br />
<br />
6|β2|<br />
+ 1 +<br />
|β4|<br />
|β4|∆B<br />
(p − 2) <br />
3|β2| 2<br />
12∆B(p − 2)<br />
|β4|<br />
1/4<br />
. <br />
<br />
<br />
<br />
Ωopt =<br />
12∆B(p − 2)<br />
|β4|<br />
1/4<br />
, (p > 2).
p > 2<br />
β2 = 0 p > 2 <br />
β2 <br />
<br />
<br />
<br />
β2 <br />
β2 5 × 10 −4 ps 2 /m β2 Ωopt(β4 = 0) <br />
β2 → 0 Ωopt(β4 = 0) <br />
<br />
<br />
<br />
β2 <br />
β2 → 0 <br />
<br />
∆B < 0 <br />
<br />
<br />
<br />
<br />
<br />
Ω =<br />
6|β2|<br />
−<br />
|β4|<br />
<br />
6|β2|<br />
+ 1 +<br />
|β4|<br />
2 |β4|<br />
(γP<br />
3 |β2| 2 3<br />
+ |∆B|). <br />
<br />
<br />
Ωopt = Ω0<br />
<br />
<br />
<br />
<br />
−1 + 1 + |∆B||β4|(p + 2)<br />
3|β2| 2 .
opt [THz]<br />
25<br />
20<br />
15<br />
10<br />
5<br />
Axe rapi<strong>de</strong><br />
(a) p=3 4 =210 -7<br />
0 1 2<br />
2 [ps 2 m -1 ]<br />
ps 4 m -1<br />
x 10 -3<br />
28<br />
26<br />
24<br />
22<br />
20<br />
18<br />
16<br />
14<br />
12<br />
10<br />
8<br />
Axe lent<br />
(b) p=3 4 =210 -7<br />
0 1 2<br />
2 [ps 2 m -1 ]<br />
ps 4 m -1<br />
x 10 -3<br />
Ωopt <br />
β4 = 2 × 10 −7 ps 4 /m
β2 → 0<br />
<br />
Ωopt =<br />
12|∆B|(p + 2)<br />
|β4|<br />
1/4<br />
, <br />
<br />
p<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
β2 <br />
σ4 = −1<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
∆B > 0
Ω1,2 =<br />
<br />
<br />
<br />
6|β2|<br />
|β4|<br />
<br />
Ω0 =<br />
<br />
6|β2|<br />
,<br />
|β4|<br />
<br />
6|β2|<br />
±<br />
|β4|<br />
1 + 2 |β4| γP<br />
(|∆B| − ).<br />
3 |β2| 2 3<br />
<br />
<br />
Ω1,2 = Ω0<br />
<br />
<br />
<br />
<br />
1 ± 1 + |∆B||β4|(2 − p)<br />
3|β2| 2 . <br />
<br />
<br />
p p < 2 <br />
β4 0 β4 < 0 <br />
<br />
<br />
<br />
<br />
Ω3 = Ω0<br />
p > 2 |β41| =<br />
<br />
<br />
<br />
<br />
<br />
1 + 1 + |∆B||β4|(2 − p)<br />
3|β2| 2 . <br />
Ω1,2 = Ω0<br />
3|β2| 2<br />
<br />
|∆B|(p−2)<br />
<br />
<br />
<br />
<br />
1 ± 1 − |β4|<br />
. <br />
|β41|<br />
<br />
|β4| < |β41| <br />
<br />
Ω1,2<br />
|β4| > |β41| <br />
Ω0
β2 > 0 <br />
β4 < 0 <br />
<br />
<br />
p < 2 <br />
<br />
±Ω3 <br />
<br />
<br />
p > 2 <br />
|β4| <br />
|β41| β41<br />
β4 β4 <br />
<br />
<br />
β2 β4<br />
∆B < 0 <br />
<br />
<br />
<br />
Ω1,2 = Ω0<br />
<br />
6|β2|<br />
Ω0 = , <br />
|β4|<br />
<br />
<br />
<br />
<br />
1 ± 1 − |∆B||β4|(p + 2)<br />
3|β2| 2 . <br />
<br />
|β42| =<br />
<br />
3|β2| 2<br />
<br />
|∆B|(p+2)
Ω1,2 = Ω0<br />
<br />
<br />
<br />
<br />
<br />
1 ± 1 − |β4|<br />
. <br />
|β42|<br />
|β4| < |β42| <br />
<br />
Ω1,2<br />
|β4| > |β42| <br />
±Ω0 <br />
<br />
<br />
<br />
β2 β4 =<br />
−4 × 10 −7 ps 4 m −1 <br />
<br />
<br />
<br />
<br />
<br />
p = 1 p < pl = 2 <br />
±Ω3 Ω3 <br />
β2 <br />
<br />
Ω3 <br />
<br />
p = 3 <br />
±Ω1 ±Ω2 <br />
p > pl = 2 <br />
Ω2 <br />
β2 Ω3 Ω2<br />
<br />
Ω1
opt [THz]<br />
opt [THz]<br />
35<br />
30<br />
25<br />
20<br />
15<br />
35<br />
30<br />
25<br />
20<br />
15<br />
10<br />
5<br />
0<br />
Axe rapi<strong>de</strong><br />
(a1) p=1<br />
3<br />
(b1) p=3<br />
0<br />
2<br />
1<br />
35 (a2) p=1<br />
30<br />
25<br />
20<br />
15<br />
10<br />
40<br />
35<br />
30<br />
25<br />
20<br />
15<br />
5 10 15<br />
x 10 -4<br />
[ps<br />
2 2 m -1 10<br />
]<br />
0<br />
Axe lent<br />
2<br />
1<br />
(b2) p=3<br />
4 = 0<br />
0<br />
4 # 0<br />
2<br />
1<br />
5 10 15<br />
x 10 -4<br />
[ps<br />
2 2 m -1 ]<br />
Ωopt <br />
β4 = −4 × 10 −7 ps 4 /m <br />
<br />
β4
β2 <br />
Ω2 Ω0 <br />
Ω0 <br />
<br />
<br />
<br />
p = 3 <br />
<br />
<br />
<br />
Ω0 Ω2 Ω3 Ω0 Ω3 <br />
<br />
Ω2 Ω3<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
β2 = 1.5 ps 2 km −1 γ = 0.023 W −1 m −1 λ = 576 nm B = 10 −7 <br />
<br />
<br />
p < pl = 2 <br />
±20 T Hz β4 = 0 <br />
<br />
pl = 2 <br />
<br />
p = 3 p = 5
Gain [m -1 ]<br />
Gain [m -1 ]<br />
7<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
(a1)<br />
(b1)<br />
p=5<br />
ASL<br />
P F =pP c P s =0<br />
3 3<br />
1<br />
P s =pP c P F =0<br />
p=5<br />
3<br />
1 1<br />
5 10 15 20 25<br />
Frequence [THz]<br />
(a2)<br />
(b2)<br />
p=5<br />
ESNL<br />
4 = -2.6 10 -6<br />
3 3<br />
p=5<br />
3<br />
1 1<br />
1<br />
ps 4 m -1<br />
4 = -10 -6 ps 4 m -1<br />
5 10 15 20 25<br />
Frequence [THz]<br />
<br />
<br />
p Pf Ps <br />
β2 = 1.5 ps 2 km −1 γ = 0.023 W −1 m −1 λ = 576 nm B = 10 −7
pf 4.5 <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
p = pl = 2<br />
±Ω3 <br />
±Ω1, ±Ω2 <br />
p pl = 2 ±Ω1 ±Ω2 <br />
±Ω0<br />
<br />
<br />
<br />
β4 p
G opt [m -1 ]<br />
opt [THz]<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
(a1)<br />
16 (b1)<br />
14<br />
12<br />
10<br />
8<br />
6<br />
4<br />
2<br />
0<br />
3<br />
P F = pP c P s = 0<br />
4 = -2.6 10 -6<br />
ps 4 m -1<br />
2<br />
1<br />
1 2 3 4 5<br />
Puissance normalisée<br />
0<br />
(a2)<br />
(b2)<br />
P F = 0 P s = pP c<br />
4 = - 10 -6 ps 4 m -1<br />
2<br />
1<br />
1 2 3 4 5<br />
Puissance normalisée<br />
<br />
<br />
<br />
±Ω0 <br />
<br />
0
±Ω1 ±Ω2 <br />
<br />
<br />
<br />
±Ω3 <br />
<br />
<br />
<br />
<br />
|β41| =<br />
pc = 2 +<br />
3|β2| 2<br />
, <br />
|∆B|(p − 2)<br />
2 3|β2|<br />
. <br />
|∆B||β4|<br />
β4 <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
Ω0
β 4<br />
β4c1<br />
β<br />
40<br />
Ω<br />
3<br />
Pompe polarisée suivant l’axe rapi<strong>de</strong><br />
p<br />
l<br />
II<br />
Effets <strong>de</strong>s pertes<br />
Ω1 Ω2<br />
p<br />
Réservoir<br />
<strong>de</strong><br />
Photons<br />
(RP)<br />
p<br />
c1 0<br />
I<br />
Remplissage du RP<br />
Ω0<br />
β 41<br />
(a)<br />
Puissance normalisée<br />
β2 > 0 <br />
β4 < 0 <br />
<br />
<br />
<br />
pl = 2 <br />
Ω3 <br />
Ω0 p <br />
|β4| <br />
β2 = 0 <br />
<br />
<br />
<br />
<br />
Ω3
β<br />
β4c1<br />
β<br />
4<br />
40<br />
Pompe polarisée suivant l’axe lent<br />
II<br />
Ω Ω 1 2<br />
Effets <strong>de</strong>s pertes<br />
p<br />
c1<br />
Réservoir<br />
<strong>de</strong><br />
Photons<br />
(RP)<br />
p<br />
0<br />
I<br />
Remplissage du RP<br />
Ω0<br />
β 42<br />
(b)<br />
Puissance normalisée<br />
β2 > 0 <br />
β4 < 0
1 β2 < 0,<br />
β4 = 0<br />
2 β2 < 0,<br />
β4 > 0<br />
3 β2 < 0,<br />
β4 < 0<br />
4 β2 = 0,<br />
β4 < 0<br />
5 β2 = 0,<br />
β4 > 0<br />
6 β2 > 0,<br />
β4 = 0<br />
7 β2 > 0,<br />
β4 > 0<br />
8 β2 > 0,<br />
β4 < 0<br />
(∆B > 0)<br />
p < 2, Ωopt =<br />
|∆B|(2−p)<br />
|β2|<br />
p > 2, <br />
<br />
p > 2, Ωopt = Ω0 1 +<br />
p < 2 <br />
|β4| < β43<br />
Ωopt± = Ω0<br />
1 ±<br />
<br />
1 − |∆B||β4|(2−p)<br />
3|β2| 2<br />
p < 2 |β4| > β43, Ωopt = Ω0<br />
p < 2, Ωopt <br />
=<br />
Ω0<br />
−1 +<br />
p > 2, <br />
<br />
1 + |∆B||β4|(2−p)<br />
3|β2| 2<br />
p < 2, Ωopt = ( 12|∆B|(2−p)<br />
) |β4|<br />
1/4<br />
p > 2, <br />
p > 2, Ωopt = ( 12|∆B|(p−2)<br />
) |β4|<br />
1/4<br />
p < 2, <br />
p > 2 , Ωopt =<br />
p < 2, <br />
p > 2 , Ωopt <br />
=<br />
Ω0<br />
−1 +<br />
|∆B|(p−2)<br />
|β2|<br />
<br />
1 + |∆B||β4|(p−2)<br />
3|β2| 2<br />
p < 2, <br />
<br />
p < 2 , Ω3 = Ω0 1 +<br />
p > 2 <br />
|β4| < β41<br />
Ω1,2 = Ω0<br />
1 ±<br />
<br />
1 + |∆B||β4|(p−2)<br />
3|β2| 2<br />
<br />
1 + |∆B||β4|(2−p)<br />
3|β2| 2<br />
<br />
1 − |∆B||β4|(p−2)<br />
3|β2| 2<br />
p > 2 |β4| > β41, Ω = Ω0<br />
(∆B <<br />
0)<br />
<br />
Ωopt =<br />
Ω0<br />
<br />
1 +<br />
<br />
<br />
<br />
1 + |∆B||β4|(p+2)<br />
3|β2| 2<br />
Ωopt = ( 12|∆B|(p+2)<br />
) |β4|<br />
1/4<br />
Ωopt =<br />
Ωopt =<br />
Ω0<br />
<br />
|∆B|(p+2)<br />
|β2|<br />
−1 +<br />
<br />
1 + |∆B||β4|(p+2)<br />
3|β2| 2<br />
|β4| < β42 Ω1,2 <br />
=<br />
Ω0<br />
1 ±<br />
<br />
1 − |∆B||β4|(p+2)<br />
3|β2| 2<br />
|β4| > β42, Ω = Ω0<br />
<br />
|β41| = 3|β2| 2 /(|∆B|(p − 2))<br />
|β42| = 3|β2| 2 /(|∆B|(p + 2)) |β43| = 3|β2| 2 /(|∆B|(2 − p))
β 4<br />
β4c1<br />
β<br />
40<br />
Ω<br />
Pompe polarisée suivant l’axe rapi<strong>de</strong><br />
3<br />
p<br />
l<br />
II<br />
Effets <strong>de</strong>s pertes<br />
Ω1 Ω2<br />
Réservoir<br />
<strong>de</strong><br />
Photons<br />
(RP)<br />
I<br />
Remplissage du RP<br />
Ω0<br />
β 41<br />
p p Puissance normalisée<br />
c1 0<br />
<br />
β4<br />
β 4<br />
β4c1<br />
β<br />
40<br />
Pompe polarisée suivant l’axe lent<br />
II<br />
Ω1 Ω2<br />
Effets <strong>de</strong>s pertes<br />
Réservoir<br />
<strong>de</strong><br />
Photons<br />
(RP)<br />
I<br />
Remplissage du RP<br />
Ω0<br />
β 42<br />
p p Puissance normalisée<br />
c1<br />
<br />
β4<br />
0
p0 <br />
pc1 <br />
p0 − pc1 <br />
<br />
<br />
<br />
<br />
|β4| <br />
|β4| <br />
|β4| <br />
p0 − pc1 <br />
<br />
<br />
<br />
p0 <br />
pl = 2 p0−pc1 p0−pl
β4 = 0 <br />
pl <br />
<br />
0 < p < pl
P <br />
L
P, L
P, L
P, L
Annexe A<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
∂A<br />
∂z<br />
= −αA<br />
2<br />
− iβ2<br />
2<br />
∂ 2 A<br />
∂t 2 + iγ |A|2 A, <br />
t vg = 1/β1
∂A<br />
∂z = ( ˆ D + ˆ N), <br />
ˆ D ˆ N<br />
<br />
ˆD = −i β2<br />
2<br />
∂2 α<br />
−<br />
∂t2 2 , ˆ N = iγ |A| 2 . <br />
<br />
h <br />
z <br />
z + h ˆ D = 0<br />
ˆ N = 0 <br />
<br />
A(z + h, t) ≈ exp(h ˆ D) exp(h ˆ N)A(z, t). <br />
∂/∂t iω <br />
ˆ D <br />
exp(h ˆ D)A(z, t) = F −1 exp[h ˆ D(iω)F ]A(z, t), <br />
F ˆ D(iω) ∂/∂t<br />
iω ω ˆ D(iω) <br />
<br />
ˆ N <br />
exp(h ˆ N)A(z, t) = exp(ih |A(z, t)| 2 )A(z, t). <br />
<br />
<br />
<br />
A(z + h, t) ≈ exp[h( ˆ D + ˆ N)]A(z, t),
ˆ N z <br />
(â) ( ˆ b) <br />
exp(â) exp( ˆ <br />
b) = exp â + ˆb + 1<br />
2 [â, ˆb] + 1<br />
12 [â − ˆb, [â, ˆ <br />
b]] + . . . , <br />
[â, ˆ b] = â ˆ b − ˆ bâ â ˆ b <br />
<br />
ˆ D ˆ N â = h ˆ D ˆ b = h ˆ N<br />
1<br />
2 h2 [ ˆ D, ˆ N] <br />
h<br />
<br />
<br />
<br />
A(z + h, t) ≈ exp( h<br />
2 ˆ D) exp(h ˆ N) exp( h<br />
2 ˆ D)A(z, t). <br />
<br />
h 3 <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
⎛<br />
∂<br />
⎝<br />
∂z<br />
Ap<br />
Aq<br />
⎞<br />
⎠ =<br />
⎡<br />
⎣ |Ap| 2 + 2<br />
3 |Aq| 2 1<br />
3 AqA ∗ p<br />
1<br />
3 ApA ∗ q<br />
|Aq| 2 + 2 2<br />
|Ap| 3<br />
⎤ ⎛<br />
⎦<br />
⎝ Ap<br />
Aq<br />
⎞<br />
⎠
2 × 2 <br />
Ap Aq <br />
<br />
<br />
Ap Aq <br />
<br />
(γ|A| 2 ) <br />
A(z, t) <br />
<br />
<br />
<br />
<br />
t <br />
<br />
<br />
<br />
<br />
<br />
<br />
A+ A− A+ A− <br />
<br />
<br />
(A+) (A−) <br />
ˆN+ = 2<br />
3 γ(|A+| 2 + 2 |A−| 2 ), ˆ N− = 2<br />
3 γ(|A−| 2 + 2 |A+| 2 ). <br />
<br />
A+ A− <br />
<br />
<br />
p q
ˆDp = i(ωδ + ∆β<br />
2<br />
β2<br />
+<br />
2 ω2 ), ˆ Dq = i(−ωδ − ∆β<br />
2<br />
+ β2<br />
2 ω2 ). <br />
<br />
<br />
ˆ Dp,q ˆ N±<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
+∞ −∞
Annexe B
256 OPTICS LETTERS / Vol. 36, No. 2 / January 15, 2011<br />
<br />
Suppression of the frequency drift of modulational<br />
instability si<strong>de</strong>bands by means of<br />
a fiber system associated with a photon reservoir<br />
M. N. Zambo Abou’ou, 1 P. Tchofo Dinda, 1, * C. M. Ngabireng, 1,3 B. Kibler, 1 F. Smektala, 1 and K. Porsezian 2<br />
1 Laboratoire Interdisciplinaire Carnot <strong>de</strong> <strong>Bourgogne</strong>, UMR CNRS No. 5027, 9 Avenue A. Savary,<br />
B.P. 47870, 21078 Dijon Cé<strong>de</strong>x, France<br />
2 Department of Physics, Pondicherry University, Pondicherry 605 014, India<br />
3 Permanent address: Ecole Nationale Supérieure Polytechnique–University of Yaoun<strong>de</strong> I, Yaoun<strong>de</strong>, Cameroon<br />
*Corresponding author: Patrice.Tchofo‑Dinda@u‑bourgogne.fr<br />
Received August 18, 2010; revised November 4, 2010; accepted November 22, 2010;<br />
posted December 14, 2010 (Doc. ID 133372); published January 13, 2011<br />
We analyze fiber systems where the linear losses act as a strong perturbation, causing a frequency drift of the modulational<br />
instability si<strong>de</strong>bands. We achieve the total suppression of this frequency drift by means of a technique<br />
based on the concept of a photon reservoir, which feeds in situ the process of modulational instability by continually<br />
supplying it the amount of photons absorbed by the fiber. © 2011 Optical Society of America<br />
OCIS co<strong>de</strong>s: 190.0190, 190.4380, 190.4410.<br />
Modulational instability (MI) in dielectric media is a<br />
well-known phenomenon in which a cw or quasi-cw un<strong>de</strong>rgoes<br />
modulation of its amplitu<strong>de</strong> or phase in the<br />
presence of noise or any other weak perturbation [1,2].<br />
When MI is used in practical applications (e.g., generation<br />
of ultrashort light pulses [2]), it becomes rather crucial<br />
that the si<strong>de</strong>band frequencies can be generated in a<br />
perfectly controlled manner. Yet, the material absorption<br />
can become a strong <strong>de</strong>trimental factor in numerous MI<br />
processes. It is a well-known fact that the physical processes<br />
that allow the nonlinearity of glass materials to be<br />
increased also induce an increase in the material’s absorption<br />
in almost the same proportion. This constitutes<br />
a serious obstacle for generalized use of such fibers in<br />
practical applications. In particular, in an MI process,<br />
the penalizing effect of the absorption inclu<strong>de</strong>s not only<br />
the pump <strong>de</strong>pletion but also un<strong>de</strong>sirable phenomena<br />
such as the frequency drifts of the MI si<strong>de</strong>bands [3]. In<br />
[3], a technique called average-dispersion <strong>de</strong>creasing dispersion-managed<br />
fibers (A3DMF) was proposed for suppressing<br />
such frequency drifts in MI processes. This<br />
technique has two major drawbacks. First, it requires important<br />
equipment and heavy manufacturing (which<br />
must be achieved by juxtaposing sections of fibers of alternately<br />
positive and negative dispersion while carefully<br />
adjusting their lengths) [3]. The second drawback is its<br />
total lack of flexibility. In<strong>de</strong>ed, once the system of<br />
A3DMF is constructed for a given pump power, it is<br />
no longer possible to adapt it to another power level.<br />
Consi<strong>de</strong>ring the recent advances ma<strong>de</strong> in the <strong>de</strong>velopment<br />
of fibers with very high nonlinearities [4–6], and the<br />
importance of such fibers in the <strong>de</strong>velopment of light<br />
sources with compact size, we <strong>de</strong>monstrate in this Letter<br />
the suppression of the frequency drift of MI si<strong>de</strong>bands in<br />
a chalcogeni<strong>de</strong> fiber with a nonlinear susceptibility 100<br />
times larger than that of standard silica fiber [5,6]. The<br />
suppression of the frequency drift is achieved by means<br />
of a technique based on the concept of a photon reservoir,<br />
which feeds in situ the MI process by continually<br />
supplying it the amount of photons absorbed by the fiber.<br />
Wave propagation in a single-mo<strong>de</strong> fiber with higheror<strong>de</strong>r<br />
dispersion and higher-or<strong>de</strong>r nonlinearities may be<br />
<strong>de</strong>scribed by the following nonlinear Schrödinger equation<br />
(NLSE) [6–8]:<br />
Az ¼ −iβ2 2 Att þ β3 6 Attt þ iβ4 24 Atttt þ i γ jAj2A αA<br />
− ; ð1Þ 2 1 þ ΓjAj 2<br />
where A is the slowly varying amplitu<strong>de</strong> of electrical-field<br />
envelope, β m is the mth or<strong>de</strong>r of the dispersion parameter,<br />
α is the linear-loss parameter, Γ ¼ 1=P s is the parameter<br />
of saturation of the nonlinearity, and P s is the<br />
saturation power. In Eq. (1), the nonlinearity saturates<br />
in a way qualitatively similar to that of a two-level system.<br />
The parameter γ takes the following form: γ ¼ γ r þ iγ i,<br />
where γ r <strong>de</strong>signates the usual Kerr parameter and γ i represents<br />
the nonlinear absorption. Using the transformation<br />
qðz; tÞ ¼ Aðz; tÞ expð−αz=2Þ, Eq. (1) becomes<br />
q z ¼ −iβ 2<br />
2 q tt þ β 3<br />
6 q ttt þ iβ 4<br />
24 q tttt þ i γ expð−αzÞjqj2 q<br />
1 þ Γjqj 2 : ð2Þ<br />
The steady-state solution of Eq. (2) can be written<br />
as qs ¼ ρðzÞ exp½iΦðzÞŠ, where the evolution of ρ and<br />
Φ along the fiber is given by dρ=dz ¼ −γiρ3 =<br />
½1 þ Γρ2 expð−αzÞŠ, dΦ=dz ¼ γrρ2 =½1 þ Γρ2 expð−αzÞŠ.<br />
The linear stability analysis (LSA) of Eq. (2) can be<br />
examined by introducing the ansatz qðz; tÞ ¼ ½ρþ<br />
pðz; tÞŠ expðiΦðzÞÞ; where jpðz; tÞj2≪ jρðz; tÞj2 . We assume<br />
for the perturbation the following ansatz with<br />
frequency <strong>de</strong>tuning from the pump Ω: pðz; tÞ ¼<br />
aðz; ΩÞ expðiΩtÞ þ aðz; −ΩÞ expð−iΩtÞ. By substituting<br />
this ansatz into Eq. (2), we obtain the following<br />
equation for the perturbed field: ∂ ^ V =∂z ¼ iM ^ V, where<br />
h i<br />
^V<br />
aðz; ΩÞ<br />
¼<br />
and the elements of the stability<br />
a ðz; −ΩÞ<br />
matrix M are given by M11 ¼ DsðΩÞ þ iγ piP ffiffiffi þ ðγrþ Q<br />
iγiÞP Q , M12 ¼ ðγrþiγ iÞP<br />
Q , M21 ¼ −M12 , and M22 ¼ −DaðΩÞþ iγ<br />
piP ffiffiffi þ<br />
Q<br />
ð−γrþiγ iÞP<br />
Q , where DsðΩÞ ¼ β2 2 Ω2 − β3 6 Ω3 þ β4 24 Ω4 ,<br />
DaðΩÞ ¼ β2 2 Ω2 þ β3 6 Ω3 þ β4 24 Ω4 , P ¼ ρ2 expð−αzÞ, and<br />
0146-9592/11/020256-03$15.00/0 © 2011 Optical Society of America
Q ¼ ½1 þ Γρ 2 expð−αzÞŠ 2 : The eigenvalues of the stability<br />
matrix M <strong>de</strong>termine the wavenumber of the perturbation,<br />
which provi<strong>de</strong>s the gain spectrum:<br />
ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi<br />
G ¼ 2 γ2 i P2Q−2 − β2 2 Ω2 þ β4 24 Ω4 þ γrP Q<br />
2<br />
þ γ s<br />
rP<br />
Q<br />
2<br />
þ2γ iPðQ −1 þ Q −1=2 Þ: ð3Þ<br />
Most of the recently <strong>de</strong>veloped glasses, like the one we<br />
consi<strong>de</strong>r in the present work, have a rather mo<strong>de</strong>rate<br />
nonlinear absorption [4] ðγi≪ 1Þ, which provi<strong>de</strong>s only<br />
a minor contribution to the MI process. Thus, an approximate<br />
but highly accurate qualitative <strong>de</strong>scription of the<br />
MI process can be obtained by neglecting γi. When this<br />
is done, the above expression of the MI gain reduces to<br />
qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi<br />
G ¼ 2<br />
, where P1 ¼<br />
ð γrP1 Q Þ<br />
1 2 − ð β2 2 Ω2 þ β4 24 Ω4 þ γrP1 Q Þ<br />
1 2<br />
P0 expð−αzÞ and Q1 ¼ ð1 þ ΓP0 expð−αzÞÞ2 . P0 is the<br />
input pump power. As we will see later, one of the conditions<br />
nee<strong>de</strong>d to create a photon reservoir in the<br />
MI process is that β2 < 0 and β4 > 0. In this case,<br />
the MI gain can be rewritten as G ¼ jβ2jΩ2jQ2j × ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi<br />
Ω2 c expð−αzÞ=ðQ1Q2Ω2 p<br />
Þ −1,<br />
where Ω2 c ¼ 4γrP0=jβ2j, Y2 ¼ jβ4j=ð12jβ2jÞ, and Q2 ¼ 1 − Y2Ω2 . In practice,<br />
P0≪ Psð⇒ P0Γ≪1;⇒ Q1 ≈ 1Þ, and<br />
G ≈ jβ2jΩ2jQ2j ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi<br />
Ω2 c expð−αzÞ=ðQ2Ω2 q<br />
Þ −1:<br />
ð4Þ<br />
Equation (4) brings to light two important points:<br />
i. In the beginning of the propagation, the losses play<br />
a minor role, and the gain is then maximum. But during<br />
the propagation, the losses progressively come into play<br />
and reduce the local gain until its total cancellation at a<br />
critical distance, which is given by z c ¼ 2α −1 lnðΩ c=ΩÞ−<br />
α −1 lnðQ 2Þ. Beyond this critical distance, the pump power<br />
is no longer sufficient for maintaining the MI process. In<br />
other words, after a critical distance of propagation, the<br />
available MI gain is no longer sufficient to compensate<br />
for the linear losses.<br />
ii. The local gain related to the actual electric field A<br />
is given by g ¼ −α þ GðΩ; zÞ. The accumulated gain is<br />
obtained by integration of the local gain over the fiber<br />
length L: ~ GðΩ; zÞ ¼ R L 0 gðΩ; zÞdz. The result differs<br />
<strong>de</strong>pending on whether L > z c or L < z c:<br />
~G ¼ −αL þ κ½WðΩ;0Þ − tan −1 ðWðΩ;0ÞÞŠ; for L > z c;<br />
ð5aÞ<br />
~G ¼ −αL þ κ½η 1 þ tan −1 ðη 1=η 2ÞŠ; for L < z c; ð5bÞ<br />
where κ ¼ α −1 jβ 2jΩ 2 jQ 2j, WðΩ; xÞ ¼ ½ζ expð−αxÞ −1Š 1=2 ,<br />
ζ ¼ Ω 2 c=½Ω 2 Q 2Š, η 1 ¼ WðΩ;0Þ − WðΩ; LÞ, and η 2 ¼ 1−<br />
WðΩ;0ÞWðΩ; LÞ. From Eqs. (5a) and (5b) one can obtain<br />
the following expression of the optimum modulation<br />
frequency (OMF):<br />
January 15, 2011 / Vol. 36, No. 2 / OPTICS LETTERS 257<br />
Ω 1;2 ¼ Ω 0 1<br />
Ω 1;2 ¼ Ω 0 1<br />
qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 1=2<br />
1 − P0=P0cL ; for L < zc; ð6aÞ<br />
pffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 1=2<br />
1 − P0=P0c ; for L ≥ zc; ð6bÞ<br />
qffiffiffiffiffiffiffi<br />
6jβ<br />
where Ω0 ¼ 2j<br />
jβ , P0cL ¼<br />
4j<br />
3jβ2j2ðexpðαLÞþ1Þ 4γ , P<br />
rjβ4j 0c ¼ 3jβ2j2ðθ2 þ1Þ<br />
4γ ,<br />
rjβ4j and θ ¼ 2:331 is the nonzero solution of the equation<br />
θ −2 tan−1 θ ¼ 0, which is obtained in solving ∂ ~ G =∂Ω<br />
for L > zc. Thus, Eq. (6a) <strong>de</strong>monstrates explicitly the<br />
functional <strong>de</strong>pen<strong>de</strong>nce of the OMF on the loss parameter<br />
α and the fiber length L. In other words, the si<strong>de</strong>bands<br />
execute a frequency drift which takes place as long as<br />
the pump power is sufficient for maintaining the MI process.<br />
At this juncture, an important fact reported recently<br />
[7] is that the interplay among the second-or<strong>de</strong>r dispersion<br />
with β2 < 0, the fourth-or<strong>de</strong>r dispersion (FOD) with<br />
β4 > 0, and the Kerr nonlinearity leads to a surprising<br />
diagram ma<strong>de</strong> of two domains corresponding to two<br />
main types of MI processes, namely, processes of type<br />
I (which generate a single pair of si<strong>de</strong>bands Ω0) and<br />
processes of type II (which generate two pairs of si<strong>de</strong>bands:<br />
Ω1, Ω2), as schematically represented in<br />
Fig. 1. Now, it is crucial to notice that in the MI domain<br />
of type I, the si<strong>de</strong>band frequency is quasi-in<strong>de</strong>pen<strong>de</strong>nt of<br />
the pump power. Then the fundamental i<strong>de</strong>a of our procedure<br />
for suppressing the frequency drifts induced by<br />
the fiber losses lies in the choice of an operating condition<br />
such that the MI phenomenon remains entirely in the<br />
MI domain of type I from the beginning to the end of the<br />
propagation. Then, the question arises as to the conditions<br />
of access and operation in the MI domain of<br />
type I. Now, Fig. 1 shows that two branches<br />
pffiffiffiffi of critical<br />
2 powers [given by [7]: Pc1;c2 ≡ ð1 −2Γξ ΔÞ=ð2ξΓ<br />
Þ,<br />
where Δ ¼ 1 −4Γξ and ξ ≡3jβ2j2 =ð2γjβ4jÞ] encompass<br />
the MI domain of type I.<br />
Therefore, to achieve the suppression of the frequency<br />
drifts of the MI si<strong>de</strong>bands, the input pump power P 0 must<br />
be sufficiently larger than the lower branch of the critical<br />
powers (P 0 > P c1) that the final pump power is also<br />
Fig. 1. Schematic representation of the MI map in the fiber<br />
system for β 2 < 0 and β 4 > 0.
258 OPTICS LETTERS / Vol. 36, No. 2 / January 15, 2011<br />
larger than P c1½Pðz ¼ LÞ ≥ P c1Š. The gap between P 0 and<br />
the lower branch of the critical powers corresponds to a<br />
photon reservoir <strong>de</strong>fined by Rðz ¼ 0Þ ¼ P 0 − P c1ðβ 2; β 4Þ.<br />
In our procedure, we choose the initial pump power<br />
so that the initial capacity of the photon reservoir is just<br />
enough to compensate in advance for the total drop of<br />
power that the losses will inflict on the pump. Thus,<br />
P 0 ¼ P c1ðβ 2; β 4Þ × expðαLÞ: ð7Þ<br />
In other words, the photon reservoir is sized so that it<br />
empties completely at the end of the propagation<br />
½Pðz ¼ LÞ ¼ P c1Š. In practice, our choice of the initial condition<br />
of the system can be ma<strong>de</strong> by means of a laser<br />
source with tunable power. The initial pump power is<br />
tuned to the appropriate level <strong>de</strong>scribed by Eq. (7)and<br />
schematically illustrated in Fig. 1.<br />
The above analysis is remarkably illustrated in Fig. 2,<br />
which shows the MI gain and the si<strong>de</strong>band frequencies<br />
that we have obtained for a typical example of fiber<br />
having both a high nonlinearity and a strong linear absorption,<br />
namely, a 728 nm diameter core As 2S 3 nanofiber<br />
with borosilicate glass cladding [6], and with:<br />
α ¼ 1 dB=m, γ r ¼ 35 × 10 3 W −1 km −1 , β 2 ¼ −2:6 ps 2 =km,<br />
β 4 ¼ 9 × 10 −3 ps 4 =km (at 1420 nm), and L ¼ 6 m. The dispersive<br />
and nonlinear characteristics are those of the<br />
fundamental mo<strong>de</strong> HE11, calculated by use of the conventional<br />
theory of step-in<strong>de</strong>x fibers with a circular cross<br />
section [6]. The corresponding critical power is<br />
P c1 ¼ 33 mW. Figure 2 exhibits three major points: (i)<br />
The input power P 0 ¼ 35 mWð≈ P c1Þ falls in the immediate<br />
vicinity of the MI domain of type II, and there the si<strong>de</strong>band<br />
frequencies vary continually with the propagation<br />
distance z [as Figs. 2(b1) and 2(b2) show]. (ii) The power<br />
P 0 ¼ 55 mW is greater than P c1, but not enough to fill the<br />
photon reservoir. Consequently, the frequency drift of<br />
the si<strong>de</strong>bands is suppressed, but only from the beginning<br />
of the propagation until the total emptying of the reservoir,<br />
which occurs at z∼4:2 m [as shown by the circle<br />
symbols in Figs. 2(b1) and 2(b2)]. After this distance<br />
the fiber losses cause a continual frequency drift of<br />
the si<strong>de</strong>bands. (iii) The power P 0 ¼ 0:13 W is sufficiently<br />
large to completely fill the photon reservoir. Consequently,<br />
the frequency drift of the si<strong>de</strong>bands is completely<br />
suppressed [as shown by the cross symbols in<br />
Figs. 2(b1) and 2(b2)]. Our analytical approach of LSA<br />
is remarkably well confirmed by the direct resolution<br />
of the NLSE (1), as illustrated in Figs. 2(a1) and 2(b1)<br />
and Figs. 2(a2) and 2(b2).<br />
To conclu<strong>de</strong>, we have <strong>de</strong>monstrated an approach<br />
based on a fiber system associated with a photon reservoir,<br />
which permits suppression in situ of the lossinduced<br />
frequency drifts in MI spectra. However, if<br />
several physical effects participate in the pump <strong>de</strong>pletion,<br />
the size of the photon reservoir must simply be adjusted<br />
to compensate for the total losses un<strong>de</strong>rgone by<br />
the pump. Our approach requires new optical components<br />
that are manufacturable with the current fiber technologies<br />
and is much easier to implement than the<br />
previous approach based on dispersion-managed fibers<br />
[3]. The ability of our system to generate waves at stable<br />
<br />
Fig. 2. Accumulated MI gain for L ¼ 6 m, and OMF Ω opt versus<br />
distance z.<br />
and perfectly controlled frequencies is a highly <strong>de</strong>man<strong>de</strong>d<br />
property for the <strong>de</strong>velopment of stable light<br />
sources of ultrafast pulses.<br />
This work has been carried un<strong>de</strong>r contract IFC/3504-F/<br />
2005/2064 between the Indo-French Center for the Promotion<br />
of Advanced Research and the University of<br />
Burgundy and the University of Pondicherry.<br />
References<br />
1. G. P. Agrawal, Nonlinear Fiber Optics, 4th ed. (Aca<strong>de</strong>mic,<br />
2008).<br />
2. A. Hasegawa, Opt. Lett. 9, 288 (1984).<br />
3. A. Labruyere, S. Ambomo, C. M. Ngabireng,<br />
P. Tchofo Dinda, K. Nakkeeran, and K. Porsezian, Opt. Lett.<br />
32, 1287 (2007).<br />
4. Y. F. Chen, K. Beckwitt, F. K. Wise, B. G. Aitken,<br />
J. S. Sanghera, and I. D. Aggarwal, J. Opt. Soc. Am. B<br />
23, 347 (2006).<br />
5. M. El-Amraoui, J. Fatome, J. C. Jules, B. Kibler, G. Gadret,<br />
C. Fortier, F. Smektala, I. Skripatchev, C. F. Polacchini,<br />
Y. Messad<strong>de</strong>q, J. Troles, L. Brilland, M. Szpulak, and<br />
G. Renversez, Opt. Express 18, 4547 (2010).<br />
6. C. Chaudhari, T. Suzuki, and Y. Ohishi, J. Lightwave<br />
Technol. 27, 2095 (2009).<br />
7. P. Tchofo Dinda and K. Porsezian, J. Opt. Soc. Am. B 27,<br />
1143 (2010).<br />
8. S. B. Cavalcanti, J. C. Cressoni, H. R. da Cruz, and<br />
A. S. Gouveia-Neto, Phys. Rev. A 43, 6162 (1991).
1518 J. Opt. Soc. Am. B / Vol. 28, No. 6 / June 2011 Zambo Abou’ou et al.<br />
Impact of the material absorption on the modulational<br />
instability spectra of wave propagation<br />
in high-in<strong>de</strong>x glass fibers<br />
M. N. Zambo Abou’ou, P. Tchofo Dinda,* C. M. Ngabireng, B. Kibler, and F. Smektala<br />
Laboratoire Interdisciplinaire Carnot <strong>de</strong> <strong>Bourgogne</strong>, UMR CNRS No. 5027, 9 Avenue A. Savary,<br />
B.P. 47 870, 21078 Dijon Cé<strong>de</strong>x, France<br />
*Corresponding author: Patrice.Tchofo‐Dinda@u‐bourgogne.fr<br />
Received November 29, 2010; revised March 13, 2011; accepted April 19, 2011;<br />
posted April 19, 2011 (Doc. ID 138808); published May 24, 2011<br />
We examine the behavior of modulational instability (MI) in several classes of high-in<strong>de</strong>x glass fibers that are being<br />
<strong>de</strong>veloped to obtain very high nonlinearities and soften the conditions of generation of highly efficient light<br />
sources, namely, telecommunication fibers, air-silica microstructured fibers, tapered fibers, and nonsilica glass<br />
fibers. We perform a comparative assessment of their respective performances in MI processes on the basis of<br />
three major performance criteria: the level of the input pump power, the fiber length, and the magnitu<strong>de</strong> of<br />
the frequency drifts. In<strong>de</strong>ed, we show that the effectiveness of MI processes in such fibers is not merely influenced<br />
by the strength of the nonlinearity, but is also strongly <strong>de</strong>termined by the linear attenuation of waves in the fiber<br />
material. In those high-in<strong>de</strong>x glass fibers, this attenuation acts as a strong perturbation, causing a frequency drift of<br />
the MI si<strong>de</strong>bands. However, we show that this frequency drift can be totally suppressed by means of a technique<br />
based on the concept of a photon reservoir, which feeds in situ the process of MI by continually supplying it the<br />
amount of photons absorbed by the fiber. © 2011 Optical Society of America<br />
OCIS co<strong>de</strong>s: 190.0190, 190.4380, 190.4410.<br />
1. INTRODUCTION<br />
The phenomena of linear or nonlinear absorption of electromagnetic<br />
waves in dielectric materials constitute a source of<br />
penalty for the performance of numerous optical <strong>de</strong>vices. A<br />
well-known example of such <strong>de</strong>vices is a long-haul transmission<br />
line, in which the linear absorption in the fiber imposes<br />
a systematic reamplification of signals with a period of the<br />
or<strong>de</strong>r of a few tens of kilometers [1], leading to a consi<strong>de</strong>rable<br />
enhancement of the cost of the system. Although the optical<br />
amplification enables one to resolve effectively the absorption<br />
phenomenon in telecommunication fibers, the absorption<br />
constitutes even at present one of the constraints of <strong>de</strong>velopment<br />
of certain optical functions having practical applications.<br />
Many of these applications exploit propagation<br />
phenomena, such as the self-phase modulation, the stimulated<br />
Raman scattering, four-photon mixing, or the modulational<br />
instability (MI).<br />
MI in dielectric media is a well-known phenomenon in<br />
which a cw or quasi-cw un<strong>de</strong>rgoes a modulation of its amplitu<strong>de</strong><br />
or phase in the presence of noise or any other weak perturbation<br />
[1,2]. In the spectral domain, MI generates si<strong>de</strong>bands<br />
on each si<strong>de</strong> of the pump. Until now, MI has been examined in<br />
the literature in two distinct directions. Some work has been<br />
carried out from the viewpoint of its harmful effects in some<br />
optical <strong>de</strong>vices, such as MI lasers [3,4], or optical communications<br />
lines using the non-return-to-zero co<strong>de</strong> [5]. The main<br />
objective of those previous works was, naturally, to propose<br />
methods enabling a reduction of the harmful action of MI<br />
[3–5]. Parallel to this approach of MI, many other studies<br />
have examined this phenomenon in or<strong>de</strong>r to exploit it to<br />
achieve useful optical functions, such as optical amplification,<br />
frequency conversion, or generation of pulse trains at an<br />
0740-3224/11/061518-11$15.00/0 © 2011 Optical Society of America<br />
ultrahigh repetition rate [6–11]. In the present study, we examine<br />
the MI phenomenon from the viewpoint of its application<br />
to the generation of new optical frequencies. When MI is<br />
used in practical applications (e.g., generation of ultrashort<br />
light pulses [2]), it becomes rather crucial that the si<strong>de</strong>band<br />
frequencies can be generated in a perfectly controlled manner.<br />
However, several types of factors can disrupt a MI process,<br />
as well as its control, in a more or less severe manner<br />
<strong>de</strong>pending on the conditions of injection of the pump into the<br />
system and the physical parameters of the fiber. One of the<br />
penalizing factors in many processes of MI is the material<br />
absorption [12]. Hence, the use of very long fibers (which have<br />
as advantage to increase the cumulative MI gain) exacerbates<br />
the effects of absorption. Also, the use of a pump frequency<br />
far from the transparency windows of the fiber system can<br />
increase, by several or<strong>de</strong>rs of magnitu<strong>de</strong>, the absorption<br />
parameter of the fiber. An even more important enhancement<br />
of the absorption coefficient is observed in fibers having very<br />
high nonlinearities, such as semiconductor-doped glasses<br />
[13–19], sulphi<strong>de</strong> glasses, or heavy-metal-doped oxi<strong>de</strong> glasses<br />
[20–22]. More generally, the increase of the nonlinearity of<br />
glass materials induces also an increase of the linear absorption<br />
almost in the same proportion. This constitutes an obstacle<br />
for a generalized use of high-in<strong>de</strong>x fibers in practical<br />
applications. In this context, it is natural to ask the following<br />
question: Are high-in<strong>de</strong>x fibers (which are currently receiving<br />
much attention) really the most effective to generate new optical<br />
frequencies? In other words, are the benefits associated<br />
with the rise of the coefficient of nonlinearity of these fibers<br />
merely thwarted by the strong absorption in those materials?<br />
In the present study, we give answers to these questions.<br />
We carry out a benchmarking of several major classes of glass
Zambo Abou’ou et al. Vol. 28, No. 6 / June 2011 / J. Opt. Soc. Am. B 1519<br />
fibers in the processes of MI, namely, the telecommunication<br />
fibers, air-silica microstructured fibers, tapered fibers, and<br />
nonsilica glass fibers (chalcogeni<strong>de</strong> and tellurite fibers). To<br />
facilitate comparison between these categories of fibers,<br />
we consi<strong>de</strong>r three major performance indicators: the level of<br />
the input pump power, the fiber length, and the magnitu<strong>de</strong> of<br />
the frequency drifts. In<strong>de</strong>ed, the penalizing effect of a strong<br />
absorption inclu<strong>de</strong>s not only the pump <strong>de</strong>pletion but also an<br />
un<strong>de</strong>sirable phenomenon that is the frequency drift of the MI<br />
si<strong>de</strong>bands, as was shown by Labruyere et al. [12]. In [12], a<br />
technique called average-dispersion <strong>de</strong>creasing dispersionmanaged<br />
fibers (A3DMF) was proposed for suppressing the<br />
frequency drifts in MI processes. The A3DMF technique consists<br />
in lowering the dispersion parameter along the fiber, in<br />
the direction of propagation, in an equivalent proportion to<br />
the <strong>de</strong>crease induced by the losses on the pump power [12].<br />
This technique has two major drawbacks: first, it requires important<br />
equipments and a heavy manufacturing (because the<br />
dispersion management along the fiber is achieved by juxtaposing<br />
sections of fibers of alternately positive and negative<br />
dispersion, while carefully adjusting their lengths). The second<br />
drawback is its total lack of flexibility. In<strong>de</strong>ed, once the<br />
A3DMF system is constructed for a given pump power, it<br />
is no longer possible to adapt it to another power level. These<br />
drawbacks prohibit the practical application of the A3DMF<br />
technique to the management of the loss effects in fibers with<br />
strong nonlinearities. To circumvent the drawbacks of the<br />
A3DMF technique, a new method for suppressing the frequency<br />
drifts has been proposed recently [23]. The suppression<br />
technique is based on the concept of a photon<br />
reservoir, which feeds in situ the MI process by continually<br />
supplying it the amount of photons absorbed by the fiber [23].<br />
However, in [23], the photon reservoir is obtained by raising<br />
the pump power to a certain level, which <strong>de</strong>pends on physical<br />
parameters of the fiber. This procedure thereby requires a<br />
pump source of tunable power. In the present study, we show<br />
that a photon reservoir can also be created with a pump<br />
source with fixed power, but through a procedure that requires<br />
a careful <strong>de</strong>sign of dispersion parameters of the fiber.<br />
Finally, we show that chalcogeni<strong>de</strong> and tellurite fibers with<br />
mo<strong>de</strong>rate absorption coefficients (≤1 dB=m), in operating conditions<br />
of suppression of the frequency drifts, appear to be the<br />
most efficient systems for producing MI processes.<br />
The paper is organized as follows: In Section 2, we present<br />
the theoretical mo<strong>de</strong>l. In Section 3, we present and discuss<br />
a comparative analysis of the performance of the abovementioned<br />
highly nonlinear fibers (HNLFs). In Section 4, we<br />
present a method of suppression of the si<strong>de</strong>band frequency<br />
drifts. In Section 5, we discuss smothering processes and<br />
conclu<strong>de</strong> in Section 6.<br />
2. THEORETICAL MODEL AND GENERAL<br />
QUALITATIVE CONSIDERATIONS<br />
The theoretical mo<strong>de</strong>l of the fiber systems un<strong>de</strong>r consi<strong>de</strong>ration<br />
was recently presented in a preliminary report [23].<br />
However, to facilitate the un<strong>de</strong>rstanding of the present study<br />
and make it clear and complete, we consi<strong>de</strong>r it useful to remind<br />
the rea<strong>de</strong>r of this theoretical mo<strong>de</strong>l. Wave propagation<br />
in a single-mo<strong>de</strong> fiber with higher-or<strong>de</strong>r dispersion and higheror<strong>de</strong>r<br />
nonlinearities may be <strong>de</strong>scribed by the following nonlinear<br />
Schrödinger equation (NLSE) [23–25]:<br />
<br />
Az ¼ −iβ2 2 Att þ β3 6 Attt þ iβ4 24 Atttt þ i γ jAj2A αA<br />
− ; ð1Þ 2 1 þ ΓjAj 2<br />
where A is the slowly varying amplitu<strong>de</strong> of electrical field envelope,<br />
β m is the mth or<strong>de</strong>r of the dispersion parameter, α is<br />
the linear-loss parameter, Γ ¼ 1=P s is the parameter of saturation<br />
of the nonlinearity, and P s is the saturation power. In<br />
Eq. (1), the nonlinearity saturates in a way qualitatively similar<br />
to that of a two-level system. The parameter γ takes the<br />
following form: γ ¼ γ r þ iγ i, where γ r <strong>de</strong>signates the usual<br />
Kerr parameter and γ i represents the nonlinear absorption.<br />
Using the transformation qðz; tÞ ¼ Aðz; tÞ expð−αz=2Þ, Eq. (1)<br />
becomes<br />
q z ¼ −iβ 2<br />
2 q tt þ β 3<br />
6 q ttt þ iβ 4<br />
24 q tttt þ i γ expð−αzÞjqj2 q<br />
1 þ Γjqj 2 : ð2Þ<br />
The steady-state solution of Eq. (2) can be written as<br />
q s ¼ ρðzÞ exp½iΦðzÞŠ, where the evolution of ρ and Φ along the<br />
fiber is given by<br />
dρ=dz ¼ −γ iρ 3 =½1 þ Γρ 2 expð−αzÞŠ; ð3Þ<br />
dΦ=dz ¼ γ rρ 2 =½1 þ Γρ 2 expð−αzÞŠ: ð4Þ<br />
The linear stability analysis (LSA) of the propagation Eq. (2)<br />
can be examined by <strong>de</strong>composing the field q as follows:<br />
qðz; tÞ ¼ ½ρ þ εðz; tÞŠ expðiΦðzÞÞ; ð5Þ<br />
where ε is a perturbation field with jεðz; tÞj 2 ≪ jρðzÞj 2 . By substituting<br />
Eq. (5) into Eq. (2), and linearizing the resulting equation,<br />
we obtain the following equation for the perturbation:<br />
ε z ¼ iΩ 2 β 2<br />
2 ε þ iΩ3 β 3<br />
6 ε þ iΩ4 β 4<br />
24 ε þ iγ rP 0ðε þ ε Þ expð−αzÞ:<br />
Here, for the perturbation, we assume the following expression<br />
with frequency <strong>de</strong>tuning from the pump Ω: εðz; tÞ ¼<br />
u sðz; ΩÞ expðiΩtÞ þ u aðz; −ΩÞ expð−iΩtÞ, where u sðz; ΩÞ and<br />
u aðz; −ΩÞ are the complex perturbation amplitu<strong>de</strong>s corresponding<br />
to the anti-Stokes and Stokes si<strong>de</strong>bands, respectively.<br />
By substituting the ansatz Eq. (5) into Eq. (2), we<br />
obtain the following equation for the perturbed field:<br />
∂<br />
∂z<br />
u s<br />
u a<br />
¼ iM u s<br />
u a<br />
where the stability matrix M is given by<br />
M ¼ m 11 m 12<br />
m 21 m 22<br />
≡ DsðΩÞ þ iγiP ffiffi<br />
Q<br />
p þ ðγrþiγ iÞP<br />
Q<br />
ð−γrþiγ iÞP<br />
Q<br />
ð6Þ<br />
; ð7Þ<br />
−D aðΩÞ þ iγ iP<br />
ðγrþiγ iÞP<br />
Q<br />
pffiffiffi þ<br />
Q<br />
ð−γrþiγ iÞP<br />
Q<br />
with DsðΩÞ ¼ β2 2 Ω2 − β3 6 Ω3 þ β4 24 Ω4 , DaðΩÞ ¼ β2 2 Ω2 þ β3 P ¼ ρðzÞ2 expð−αzÞ, and Q ¼ ½1 þ ΓρðzÞ2 expð−αzÞŠ2 .<br />
;<br />
ð8Þ<br />
6 Ω3 þ β4 24 Ω4 ,
1520 J. Opt. Soc. Am. B / Vol. 28, No. 6 / June 2011 Zambo Abou’ou et al.<br />
At this stage, there are at least two ways to obtain the<br />
power gain of the si<strong>de</strong>bands. First, one can use the lowestor<strong>de</strong>r<br />
approximation of the spatial evolution of the pump<br />
power, which is commonly called “adiabatic approximation.”<br />
In the present study, we refer to this approximation as the “approximate<br />
LSA” (ALSA). The main advantage of the ALSA lies<br />
in its relative simplicity, which enables one to proceed quite<br />
far in analytical formulas. However, it has been shown that, in<br />
some complex systems, one can not rely solely on the ALSA<br />
for having a clear insight into the system behavior [3–5]. In<br />
particular, whenever the pump power un<strong>de</strong>rgoes large variations<br />
during propagation, it becomes useful to carry out a<br />
more rigorous LSA without any approximation on the spatial<br />
evolution of the pump power. We refer to the rigorous LSA as<br />
the “exact LSA” (ELSA). In Subsections 2.A and 2.B, we present<br />
successively these two approaches.<br />
A. ALSA<br />
To solve Eq. (7) over an elementary step dz, we make the approximation<br />
that the pump power remains constant over the<br />
distance dz before <strong>de</strong>creasing abruptly in a proportion that is<br />
equivalent to the exponential <strong>de</strong>crease of power due to the<br />
losses in the step dz. In other words, we make the approximation<br />
that the matrix elements m ij in Eq. (7) remain constant<br />
throughout the step dz before changing in an abrupt fashion<br />
when passing to the next step. With this approximation, we<br />
can easily obtain the eigenvalues of the stability matrix M,<br />
which <strong>de</strong>termine the wavenumber of the perturbation and<br />
provi<strong>de</strong> the local-gain spectrum:<br />
Gðz; ΩÞ ¼ 2<br />
ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi<br />
2<br />
þ γ s<br />
rP<br />
Q<br />
2<br />
γ2 i P2Q−2 − β2 2 Ω2 þ β4 24 Ω4 þ γrP Q<br />
þ2γ iPðQ −1 þ Q −1=2 Þ: ð9Þ<br />
Most of the recently <strong>de</strong>veloped glasses, as the one we consi<strong>de</strong>r<br />
in the present work, have a rather mo<strong>de</strong>rate nonlinear<br />
absorption [22] (γi≪ 1), which provi<strong>de</strong>s only a minor contribution<br />
to the MI process. So, an approximate but highly accurate<br />
qualitative <strong>de</strong>scription of the MI process can be obtained<br />
by neglecting γi. In doing so, ρ becomes constant [as Eq. (3)<br />
shows] and can be rewritten as ρ ¼ ffiffiffiffiffi p<br />
P0,<br />
where P0 is the input<br />
pump power. Then, the above expression of the MI gain<br />
reduces to<br />
ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi<br />
G ¼ 2<br />
γrP1 Q1 2<br />
− β2 2 Ω2 þ β4 24 Ω4 þ γ s<br />
rP1 Q1 2<br />
; ð10Þ<br />
where P 1 ¼ P 0 expð−αzÞ and Q 1 ¼ ð1 þ ΓP 0 expð−αzÞÞ 2 . Certain<br />
conditions need to be fulfilled to create a photon reservoir<br />
in the MI process. One of these conditions is that β 2 < 0 and<br />
β 4 > 0. Un<strong>de</strong>r this condition, the MI gain can be rewritten as<br />
G ¼ jβ2jΩ2jQ2j ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi<br />
Ω2 c expð−αzÞ=ðQ1Q2Ω2 q<br />
Þ −1;<br />
ð11Þ<br />
where Ω 2 c ¼ 4γ rP 0=jβ 2j, Y 2 ¼ jβ 4j=ð12jβ 2jÞ, and Q 2 ¼ 1 − Y 2 Ω 2 .<br />
The power levels of the light sources that are usually used in<br />
the MI processes vary from a few milliwatts to a few tens of<br />
watts. Such power levels are extremely lower than the saturation<br />
power of the fiber glasses un<strong>de</strong>r consi<strong>de</strong>ration (several<br />
hundreds of watts) so that, in practice, P 0≪ P s (⇒P 0Γ≪<br />
1,⇒Q 1 ≈ 1) and a fair estimate of the expression of the local<br />
gain is given by<br />
GðΩ; zÞ ≈ jβ2jΩ2jQ2j ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi<br />
Ω2 c expð−αzÞ=ðQ2Ω2 q<br />
Þ −1:<br />
ð12Þ<br />
Equation (12) brings to light two important points:<br />
1. In the beginning of the propagation, the losses play a<br />
minor role, and the local MI gain is then maximum. However,<br />
during the propagation, the losses progressively come into<br />
play and reduce the local gain until its total cancellation at<br />
a critical distance given by z c ¼ 2α −1 lnðΩ c=ΩÞ − α −1 lnð1−<br />
Y 2 Ω 2 Þ. Beyond this critical distance, the pump power is no<br />
longer sufficient for maintaining the MI process. In other<br />
words, the available MI gain is no longer sufficient for compensating<br />
the linear losses.<br />
2. The second important point lies in the fact that the si<strong>de</strong>bands’<br />
power at a given frequency does not <strong>de</strong>pend directly on<br />
the local gain, but rather on the accumulated gain. The local<br />
gain related to the actual electric field A is given by g ¼<br />
−α þ GðΩ; zÞ. The accumulated gain is obtained by integration<br />
of the local gain over the fiber length L:<br />
~GðΩ; zÞ ≡<br />
Z L<br />
0<br />
gðΩ; zÞdz: ð13Þ<br />
The result differs <strong>de</strong>pending on whether L > z c or L < z c:<br />
where<br />
~G ¼ −αL þ κ½WðΩ;0Þ − tan −1 ðWðΩ;0ÞÞŠ; for L > z c;<br />
ð14aÞ<br />
~G ¼ −αL þ κ½η 1 þ tan −1 ðη 1=η 2ÞŠ; for L < z c; ð14bÞ<br />
κ ¼ α −1 jβ 2jΩ 2 jQ 2j; ð15aÞ<br />
WðΩ; xÞ ¼ ½ζ expð−αxÞ −1Š 1=2 ; ð15bÞ<br />
ζ ¼ Ω 2 c=½Ω 2 ð1 − Y 2 Ω 2 ÞŠ; ð15cÞ<br />
η 1 ¼ WðΩ;0Þ − WðΩ; LÞ; ð15dÞ<br />
η 2 ¼ 1 − WðΩ;0ÞWðΩ; LÞ: ð15eÞ<br />
From Eqs. (14a) and (14b), one can obtain the following<br />
expression of the optimum modulation frequency (OMF):<br />
Ω 1;2 ¼ Ω 0 1<br />
Ω 1;2 ¼ Ω 0 1<br />
qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 1=2<br />
1 − P0=P0cL ; for L < zc; ð16aÞ<br />
pffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 1=2<br />
1 − P0=P0c ; for L ≥ zc; ð16bÞ
Zambo Abou’ou et al. Vol. 28, No. 6 / June 2011 / J. Opt. Soc. Am. B 1521<br />
qffiffiffiffiffiffiffi<br />
6jβ<br />
where Ω0 ¼ 2j<br />
, P0cL ¼ 3jβ2j2 ðexpðαLÞþ1Þ<br />
, P0c ¼ 3jβ2j2 ðθ2þ1Þ , and<br />
jβ 4j<br />
4γ rjβ 4j<br />
4γ rjβ 4j<br />
θ ¼ 2:331 is the nonzero solution of the equation θ − 2 tan −1 θ<br />
¼ 0, which is obtained in solving ∂ ~ G =∂Ω for L > z c. Thus,<br />
Eq. (16a) <strong>de</strong>monstrates explicitly the functional <strong>de</strong>pen<strong>de</strong>nce<br />
of the OMF upon the loss parameter α. In other words, the<br />
si<strong>de</strong>bands execute a frequency drift that takes place as long<br />
as the pump power is sufficient for maintaining the MI<br />
process.<br />
B. ELSA<br />
To obtain the exact solutions of the LSA, we adopt a calculation<br />
procedure similar to those used in previous work [3–5].<br />
First, we combine the matrix Eq. (7) into a single equation<br />
given by<br />
d2us dz2 − iðm11 þ m22Þ þ 1 dm12 m12 dz<br />
du s<br />
dz − i dm 11<br />
dz − m 11<br />
m 12<br />
dm 12<br />
dz<br />
þ ðm 11m 22 − m 12m 21Þ u s ¼ 0: ð17Þ<br />
In the practical situation un<strong>de</strong>r consi<strong>de</strong>ration, where Γ→0,<br />
γ i ≈ 0, β 2 < 0, and β 4 > 0, Eq. (17) can be rewritten as<br />
d2us dz2 þ α þ i β3Ω3 3<br />
du s<br />
dz þ 2γ rP 0 expð−αzÞ β 2<br />
2 Ω2 þ β 4<br />
24 Ω4<br />
þ D aD s − iαD s u s ¼ 0; ð18Þ<br />
where D a and D s are <strong>de</strong>fined in Eq. (8). If we make the following<br />
change of variable<br />
x ¼ η expð−αz=2Þ; ð19Þ<br />
pffiffiffiffiffiffiffiffiffiffiffiffiffi<br />
8γrP 0D10 with η ¼ α and D10 ¼ jβ2jΩ2 2 ð1 − jβ4jΩ2 12jβ Þ, Eq. (18) reduces<br />
2j<br />
to<br />
x 2 d2 u s<br />
dx 2 − ϖx du s<br />
dx − ðx2 − μ 2 Þu s ¼ 0; ð20Þ<br />
where ϖ ¼ 1 þ 2iβ 3Ω 3 =ð3αÞ and μ 2 ¼ 4ðD 2 10 − iαD s − ðβ 3Ω 3 =<br />
6Þ 2 Þ=α 2 .<br />
Then, solving Eq. (20) by means of the Frobenius technique<br />
[26], we obtain<br />
X<br />
us ¼ C01 ∞<br />
where<br />
k¼1<br />
x 2kþr 1<br />
2 k k!<br />
Y k<br />
m¼1<br />
1<br />
ðϑ þ 2mÞ þ C X<br />
02<br />
∞<br />
1 þ ϖ<br />
r1 ¼<br />
2 þ ϑ; r2 ¼<br />
k¼1<br />
x 2kþr 2<br />
2 k k!<br />
Y k<br />
m¼1<br />
1<br />
ðϑ þ 2mÞ ;<br />
ð21Þ<br />
1 þ ϖ<br />
− ϑ; ð22Þ<br />
2<br />
with ϑ ¼ ffiffiffiffiffiffiffiffiffiffiffiffi<br />
1 − μ2 p<br />
. In Eq. (21), the constants C01 and C02 can<br />
be obtained from the initial condition of the perturbed field.<br />
Hence, by choosing the following initial condition:<br />
u sðz ¼ 0Þ ¼ u aðz ¼ 0Þ ¼ u 0<br />
dus ¼ iðm11 þ m<br />
dz<br />
12Þu0; z¼0<br />
ð23Þ<br />
Eq. (21) leads to<br />
where<br />
<br />
η r 1C 01S 1 þ η r 2C 02S 2 ¼ u 0;<br />
η r 1C 01K 1 þ η r 2C 02K 2 ¼ δu 0;<br />
K 1 ¼ ½r 1 þ d ð1Þ<br />
2 ðr 1 þ 2Þη 2 þ d ð1Þ<br />
4 ðr 1 þ 4Þη 4 þ Š;<br />
K 2 ¼ ½r 2 þ d ð2Þ<br />
2 ðr 2 þ 2Þη 2 þ d ð2Þ<br />
4 ðr 2 þ 4Þη 4 þ Š;<br />
S 1 ¼ ½1 þ d ð1Þ<br />
2 η2 þ d ð1Þ<br />
4 η4 þ Š;<br />
S 2 ¼ ½1 þ d ð2Þ<br />
2 η2 þ d ð2Þ<br />
4 η4 þ Š;<br />
δ ¼ − 2i<br />
α ðm 11 þ m 12Þ ¼ 2i<br />
α D 10;<br />
d ðjÞ 1<br />
2k ¼<br />
2kk! Y k<br />
m¼1<br />
ð24Þ<br />
1<br />
: ð25Þ<br />
ðϑ þ 2mÞ<br />
Then, solving Eq. (24), we obtain the following expressions<br />
for the constants C 01 and C 02:<br />
C01 ¼ ðδS2 − K 2Þu0 ηr1ðK 1S2 − K 2S1Þ ; C02 ¼ ðK 1 − δS1Þu0 ηr2ðK : ð26Þ<br />
1S2 − K 2S1Þ Thus, the power gain of the MI process at z ¼ L, related to the<br />
field q, is given by<br />
gðΩ; LÞ ¼ u sðLÞ<br />
u 0<br />
2<br />
: ð27Þ<br />
The gain related to the original field A is given by<br />
g AðΩ; LÞ ¼ gðΩ; LÞ − α: ð28Þ<br />
3. COMPARATIVE ANALYSIS OF THE<br />
PERFORMANCE OF HNLF<br />
Here, we perform a benchmarking of several major classes of<br />
glass fibers in the processes of MI. The fibers consi<strong>de</strong>red may<br />
be classified into the following categories.<br />
1. Telecommunication fiber: we consi<strong>de</strong>r a dispersion shift<br />
fiber, as a typical example of telecommunication fibers. Such<br />
fibers are characterized by an extremely low absorption coefficient,<br />
which is a highly <strong>de</strong>man<strong>de</strong>d property in long-distance<br />
transmission systems. Several types of telecommunication fibers<br />
with different dispersion parameters are commercially<br />
available. An appreciable advantage of telecommunication fibers<br />
is their low cost.<br />
2. Air-silica microstructured fiber: this type of fiber, which<br />
falls in the category of photonic crystal fibers (PCFs), is commercially<br />
available and inten<strong>de</strong>d for applications such as<br />
supercontinuum generation, optical parametric amplification,<br />
or generation of broad spectra around 1:55 m for optical encoding.<br />
Such fibers are characterized by a small effective core<br />
area, a high nonlinear coefficient, and a SOD coefficient that is<br />
relatively flat in the third telecommunication window [27].<br />
3. Tapered fibers: in general, those fibers are ma<strong>de</strong> of<br />
amorphous silica, tapered, and surroun<strong>de</strong>d by a layer of
1522 J. Opt. Soc. Am. B / Vol. 28, No. 6 / June 2011 Zambo Abou’ou et al.<br />
air. Its tapered profile enables one to focus light into a small<br />
effective area and to change dramatically the dispersive properties<br />
of the fiber. The fiber consi<strong>de</strong>red in this study is the tapered<br />
SMF28. Tapered fibers can have nonlinear coefficients<br />
as high as those of nonlinear PCFs while requiring much less<br />
expensive manufacturing processes than those of the PCFs.<br />
The tapered SMF28 is typically used to adjust the dispersion<br />
parameters and increase nonlinear effects so as to generate<br />
supercontinuum sources in the range of visible IR wavelength<br />
[28,29]. The fiber consi<strong>de</strong>red in our study has a cross-sectional<br />
diameter of 474 nm.<br />
4. Nonsilica glass fibers: overwhelmingly, current optical<br />
fibers are ma<strong>de</strong> from silica glass. However, in recent years several<br />
research teams have focused on the realization of optical<br />
fibers with nonsilica glasses, such as tellurite [30] or chalcogeni<strong>de</strong><br />
glasses [31]. The interest for such glasses is that they have<br />
properties that differ consi<strong>de</strong>rably from those of the silica.<br />
In<strong>de</strong>ed, those glasses have high refractive indices, which induce<br />
high nonlinear indices, and thus allow to obtain nonlinear<br />
coefficients well above that of silica. The use of these special<br />
glasses should allow supercontinuum generation in the IR<br />
range well above 2 μm, for light <strong>de</strong>tection and ranging (LIDAR)<br />
applications or nonlinear imaging. The main drawbacks of<br />
these nonsilica fibers lie in their manufacturing, which requires<br />
a special expertise; their high loss parameters; and a mechanical<br />
fragility that does not facilitate their manipulation. In this<br />
study, our choice focuses on two nonsilica glass fibers: a tellurite<br />
microfiber with a 1320 nm diameter core (80TeO 2-<br />
20Na 2O) and a borosilicate glass cladding and a chalcogeni<strong>de</strong><br />
nanofiber with a 728 nm diameter core (As 2S 3) with borosilicate<br />
glass cladding, which was proposed by Ohishi et al.<br />
[32]. Based on this fiber <strong>de</strong>sign [32], we calculated the dispersive<br />
and nonlinear characteristics of the fiber by using the fundamental<br />
HE11 mo<strong>de</strong>. The value of the core diameter was<br />
chosen so as to pump in an anomalous dispersion regime with<br />
two close zero-dispersion wavelengths, and thus, to highlight<br />
the influence of fourth-or<strong>de</strong>r dispersion (FOD) in our approach.<br />
Our calculations are based on the theory of the conventional<br />
step-in<strong>de</strong>x fibers with circular cross section [32,33]. The<br />
fiber losses, including the confinement and material losses,<br />
were fixed at 1 dB=m, knowing that the confinement loss is<br />
negligible and the material losses of the As 2S 3 and Te glasses<br />
are below 1 dB=m around 1:5 μm [34,35]. However, in practice,<br />
the overall optical losses may be higher than this value because<br />
of impurities and imperfections.<br />
Thus, the major characteristics of all the fibers <strong>de</strong>scribed<br />
above are displayed in Table 1. So that the benchmarking<br />
of the fibers consi<strong>de</strong>red be as relevant as possible, we have<br />
imposed the same requirement for each fiber: the generation<br />
of MI si<strong>de</strong>bands at a frequency around 3 THz with an accumulated<br />
gain of about 30 dB. To facilitate comparison between<br />
those fibers, we consi<strong>de</strong>r three major performance indicators:<br />
(1) the input power P 0, which <strong>de</strong>termines the cost of the pump<br />
laser; (2) the fiber length L, which <strong>de</strong>termines the possibility<br />
of miniaturization of the system; and (3) the frequency drift of<br />
the si<strong>de</strong>bands, which <strong>de</strong>termines the stability of the system,<br />
i.e., the sensitivity of the si<strong>de</strong>band frequency with respect<br />
to an alteration of the fiber parameters. In<strong>de</strong>ed, during the life<br />
of an optical system, some system parameters may un<strong>de</strong>rgo<br />
alterations due to aging of the system or damages inflicted inadvertently<br />
to the system. Mechanical acci<strong>de</strong>nts may cause an<br />
increase in the absorption coefficient or even impose a shortening<br />
of the fiber. For fibers with a particularly high absorption<br />
parameter (such as those we consi<strong>de</strong>r in this study), it is<br />
useful to quantify the sensitivity of the MI phenomenon with<br />
respect to this parameter. To this end, in our analysis, we introduced<br />
a parameter D, which is expressed in gigahertz per<br />
meter and gives the average frequency drift induced by the<br />
losses over a length of 1 m of fiber. The most competitive fiber<br />
is the one that minimizes the three major parameters mentioned<br />
above (i.e., P 0, L, D). On the other hand, for each fiber,<br />
the MI process is obtained by adjusting the parameters P 0<br />
and L. The pump power P 0 is fixed at a value that permits<br />
one to obtain a si<strong>de</strong>band frequency of about 3:5 THz. The fiber<br />
length is adjusted to a value that permits to obtain an accumulated<br />
gain of about 30 dB.<br />
Figure 1 illustrates the MI processes for the different fibers<br />
that we have consi<strong>de</strong>red. The spectra of the accumulated<br />
gains exhibit the same general feature, namely a profile with<br />
two maxima that correspond to two pairs of si<strong>de</strong>bands. For<br />
each fiber, we have displayed the evolution (with the propagation<br />
distance) of the frequency of the si<strong>de</strong>band closest to<br />
the pump. One can clearly observe two regimes in the evolution<br />
of the OMF. The first is a transient regime, during which<br />
the OMF varies strongly with the propagation distance. In this<br />
transient regime, the NLSE and ALSA give divergent predictions,<br />
which we attribute to the approximate nature of the<br />
ALSA. After the transient regime, the system enters a steady<br />
state in which the si<strong>de</strong>band frequencies un<strong>de</strong>rgo a monotonic<br />
drift. In the steady state, the ALSA predicts quantitatively well<br />
Table 1. Fiber Parameters and Performance Indicators in the MI Process<br />
Telecomunication<br />
Fiber<br />
Silica<br />
PCF<br />
Tellurite Microfiber<br />
80TeO 2-20Na 2O<br />
Tapered<br />
SMF28<br />
⊘¼474 nm<br />
Altered<br />
SMF28<br />
Chalcogeni<strong>de</strong><br />
As 2S 3<br />
Glass Nanofiber<br />
Fiber parameters λ (nm) 1550 1550 1450 490 490 1420<br />
β2 (ps2m−1 ) −2:9 × 10−5 −1:7 × 10−4 −2:13 × 10−3 −1:22 × 10−3 −2:2 × 10−2 −2:6 × 10−3 β4 (ps4m−1 ) 1:7 × 10−10 4 × 10−7 2:09 × 10−6 1:28 × 10−7 1:28 × 10−7 9 × 10−6 n2 (m2W−1 ) 2:6 × 10−20 2:6 × 10−20 3:8 × 10−19 2:6 × 10−20 2:6 × 10−20 2:8 × 10−18 α (dB km−1 ) 0.22 25 1000 10,000 10,000 1000<br />
γr 0.0019 0.011 1.52 2.35 2.35 35<br />
Performance<br />
criteria<br />
(W −1 m −1 )<br />
P0 (W) 5 5 0.86 5.5 5.5 0.035<br />
L (m) 400.5 98 8 0.6 0.7 6<br />
D<br />
(GHz m−1 )<br />
1.5 3.5 199.3 9363.3 1836.8 187
Zambo Abou’ou et al. Vol. 28, No. 6 / June 2011 / J. Opt. Soc. Am. B 1523<br />
the behavior obtained from the numerical solution of the<br />
NLSE, namely, a monotonic drift (toward the pump) of the<br />
low-frequency si<strong>de</strong>band (while the high-frequency si<strong>de</strong>band,<br />
not represented in Fig. 1, executes a drift in the opposite direction).<br />
A quite remarkable point in Fig. 1 is that the ELSA is<br />
in excellent agreement with the solution of the NLSE, both in<br />
the transient regime and in the steady state. The values of<br />
parameters (P 0, L) that enable us to obtain these MI phenomena<br />
are reported in Table 1, which shows the performance of<br />
each of the fibers consi<strong>de</strong>red. A comparative analysis of the<br />
performance criteria allow us to i<strong>de</strong>ntify several major points.<br />
1. The most strongly nonlinear fibers are those that generate<br />
the largest frequency drifts. In fact, the frequency drifts<br />
increase with the loss parameter α, which, in general, increases<br />
with the nonlinearity coefficient γ r. The telecommunication<br />
fiber generates almost no frequency drift, but<br />
requires a propagation distance (of 400 m) that is several or<strong>de</strong>rs<br />
of magnitu<strong>de</strong> greater than the lengths of the nonlinear<br />
fibers un<strong>de</strong>r consi<strong>de</strong>ration. The standard silica fiber is therefore<br />
not competitive for the realization of compact light<br />
sources.<br />
2. The PCF fiber has, as the standard fiber, the advantage<br />
of not causing a significant frequency drift. In addition, it<br />
requires a propagation distance (100 m) that is consi<strong>de</strong>rably<br />
smaller than the length of the telecommunication fiber, but<br />
that remains prohibitive for the realization of a compact<br />
<strong>de</strong>vice.<br />
3. The tapered SMF28 is the fiber with the smallest length<br />
(60 cm). This clearly constitutes a major asset. However, this<br />
fiber is also the one that has the largest loss parameter (of all<br />
the fibers consi<strong>de</strong>red) and the highest frequency drift<br />
Fig. 1. Accumulated MI gain and OMF Ω opt versus distance z.<br />
<br />
(D¼9363 GHz=m). In this regard, it is important to note that,<br />
although the amplitu<strong>de</strong> of the frequency drift is closely related<br />
to the value of the loss parameter, the <strong>de</strong>pen<strong>de</strong>nce of D with<br />
respect to the dispersion parameters and power pump is not<br />
negligible. To illustrate this point, we repeated a simulation<br />
with an altered SMF28, i.e., a fiber having the same parameters<br />
as the SMF28 (in Table 1), with the exception of<br />
the parameter β 2, which was altered and enhanced by an or<strong>de</strong>r<br />
of magnitu<strong>de</strong> (−2:2 × 10 −2 ps 2 =m). We noticed that the<br />
altered SMF28 executed a drift (D¼1836 GHz=m) that is<br />
reduced by a factor of 5 as compared to that of the true tapered<br />
fiber SMF28. In other words, the existence of a strong<br />
frequency drift in the tapered SMF28 makes the MI phenomenon<br />
very sensitive, not only to an alteration of the loss<br />
parameter but also to an alteration of the dispersion parameters<br />
of the fiber. The presence of such a frequency drift<br />
makes the tapered SMF28 less competitive than nonsilica<br />
glass fibers, which we consi<strong>de</strong>r below.<br />
4. It can be clearly observed in Table 1 that the chalcogeni<strong>de</strong><br />
and tellurite fibers, with a loss level of 1 dB=m, are those<br />
that achieve the best compromise between the different performance<br />
criteria. They have lengths of only a few meters, frequency<br />
drift rates that are an or<strong>de</strong>r of magnitu<strong>de</strong> lower than<br />
that of the tapered SMF28, and they require the lowest pump<br />
powers. In particular, the chalcogeni<strong>de</strong> fiber has the advantage<br />
of requiring the lowest pump power (35 mW), which is<br />
one or<strong>de</strong>r of magnitu<strong>de</strong> lower than the pump power required<br />
for the tellurite fiber (860 mW) to obtain the same accumulated<br />
gain.<br />
It follows from this analysis that the chalcogeni<strong>de</strong> fiber<br />
(with 1 dB=m loss level) seems to be the most competitive<br />
fiber, as it provi<strong>de</strong>s the best compromise between the three<br />
performance criteria that we have consi<strong>de</strong>red. However, this<br />
fiber generates a frequency drift rate that is still high enough<br />
to cause significant instabilities in the si<strong>de</strong>band frequency in<br />
case of alteration of the fiber parameters or fluctuation of the<br />
pump power. In Section 4, we present a method for completely<br />
suppressing the frequency drifts of MI si<strong>de</strong>bands.<br />
4. SUPPRESSION OF THE SIDEBAND<br />
FREQUENCY DRIFTS<br />
At this juncture, we would like to emphasize an important fact<br />
reported recently [24]: the interplay between the second-or<strong>de</strong>r<br />
dispersion (SOD) with β 2 < 0, the FOD with β 4 > 0, and the<br />
Kerr nonlinearity leads to a surprising diagram ma<strong>de</strong> of two<br />
domains corresponding to two main types of MI processes,<br />
namely, processes of type I (which generate a single pair of<br />
si<strong>de</strong>bands Ω 0) and processes of type II (which generate<br />
two pairs of si<strong>de</strong>bands: Ω 1, Ω 2), as schematically represented<br />
in Fig. 2. Now, it is crucial to notice that, in the MI domain<br />
of type I, the si<strong>de</strong>band frequency is in<strong>de</strong>pen<strong>de</strong>nt of the<br />
pump power. Then the fundamental i<strong>de</strong>a of our procedure for<br />
suppressing the frequency drifts induced by the fiber losses<br />
lies in the choice of an operating condition such that the MI<br />
phenomenon remains entirely in the MI domain of type I from<br />
the beginning to the end of the propagation (over the entire<br />
distance L). Then, the question arises as to the conditions of<br />
access and operation in the MI domain of type I. In this respect,<br />
one can observe in Fig. 2 that two branches of critical
1524 J. Opt. Soc. Am. B / Vol. 28, No. 6 / June 2011 Zambo Abou’ou et al.<br />
powers (<strong>de</strong>noted as P c1, P c2) encompass the MI domain of<br />
type I.<br />
The analytical expression of the critical powers is given by<br />
[24]<br />
Pc1 ≡ ð1 − 2Γξ − ffiffiffiffi p<br />
2 ΔÞ=ð2ξΓ<br />
Þ; ð29aÞ<br />
Pc2 ≡ ð1 − 2Γξ þ ffiffiffiffi p<br />
ΔÞ=ð2ξΓ2Þ;<br />
ð29bÞ<br />
where Δ ¼ 1 − 4Γξ and ξ ≡ 3jβ 2j 2 =ð2γjβ 4jÞ. The linking point<br />
of these two branches of critical powers corresponds to a critical<br />
FOD given by β 4c ≡ 6jβ 2j 2 Γ=γ r, which appears as the<br />
minimum amount of FOD nee<strong>de</strong>d to cross the bor<strong>de</strong>r between<br />
the MI domains of type I and II. However, this minimum level<br />
of FOD requires the use of a pump power equal to the saturation<br />
power P s. Our operating condition (far from the saturation<br />
power, P 0≪ P s) requires an amount of FOD much larger<br />
than β 4c for crossing the bor<strong>de</strong>r between the two types of MI<br />
domains.<br />
Thus, to achieve the suppression of the frequency drifts of<br />
the MI si<strong>de</strong>bands, the input pump power P 0 must be sufficiently<br />
larger than the lower branch of the critical powers<br />
(P 0 > P c1) so that the final pump power is also larger than<br />
P c1 [Pðz ¼ LÞ ≥ P c1]. The gap between P 0 and the lower<br />
branch of the critical powers corresponds to a photon reservoir<br />
<strong>de</strong>fined by Rðz ¼ 0Þ ¼ P 0 − P c1ðβ 2; β 4Þ. In our procedure,<br />
we choose the initial pump power so that the initial capacity of<br />
the photon reservoir is just enough to compensate in advance<br />
the total drop of power that the losses will inflict to the pump.<br />
Thus,<br />
P 0 ¼ P c1ðβ 2; β 4Þ × expðαLÞ: ð30Þ<br />
Thus, the photon reservoir is sized so that it empties completely<br />
at the end of the propagation [Pðz ¼ LÞ ¼ P c1]. In practice,<br />
our choice of the initial condition of the system can be<br />
ma<strong>de</strong> according to strategies that <strong>de</strong>pend on the constraints<br />
lying on the system parameters. We have i<strong>de</strong>ntified two possible<br />
strategies of choice of the operational conditions:<br />
Fig. 2. Schematic representation of the MI map in the fiber system<br />
for β 2 < 0 and β 4 > 0, in which the photon reservoir is created by<br />
raising the pump power.<br />
A. Filling of the Photon Reservoir for Fixed β 4 (β 4 β 40)<br />
Although this strategy was recently presented in a brief report<br />
[23], we nevertheless consi<strong>de</strong>r it useful to make a remin<strong>de</strong>r of<br />
its main lines for sake of completeness. This strategy is the<br />
one that should be adopted when one has a fiber with given<br />
dispersion parameters (β 2 and β 40) and length L. In that case,<br />
it is simply necessary to have a laser source with tunable<br />
power [23]. The initial pump power is tuned to the appropriate<br />
level <strong>de</strong>scribed by the relation (30) and schematically illustrated<br />
in Fig. 2. This procedure is remarkably illustrated in<br />
Figs. 3, which we have obtained for the chalcogeni<strong>de</strong> As 2S 3<br />
glass fiber (L ¼ 6 m, α ¼ 1 dB=m, γ r ¼ 35 W −1 m −1 , β 2 ¼<br />
−2:6 ps 2 =km, β 4 ¼ 9 × 10 −3 ps 4 =km). The corresponding critical<br />
power is P c1 ¼ 33 mW. Figures 3(a1) and 3(a2) show<br />
the spectra of the accumulated MI gain for z ¼ L ¼ 6 m.<br />
Figures 3(b1) and 3(b2) show the evolution of the si<strong>de</strong>band<br />
frequencies versus the system length. Figure 3 exhibits three<br />
major points.<br />
1. The input power P 0 ¼ 35 mWð≈ P c1Þ falls in the immediate<br />
vicinity of the MI domain of type II, and, there, the si<strong>de</strong>band<br />
frequencies vary continually with the propagation<br />
distance.<br />
2. The power P 0 ¼ 55 mW is greater than P c1, but not enough<br />
for filling the photon reservoir. Consequently, the frequency<br />
drift of the si<strong>de</strong>bands is suppressed, but only from the<br />
Fig. 3. Plots illustrating the MI processes in the operating conditions<br />
of nonsuppression of the frequency drifts (P 0 ¼ 35 mW), partial suppression<br />
of the frequency drifts (P 0 ¼ 55 mW), and total suppression<br />
of the frequency drifts (P 0 ¼ 130 mW) for the chalcogeni<strong>de</strong> fiber.
Zambo Abou’ou et al. Vol. 28, No. 6 / June 2011 / J. Opt. Soc. Am. B 1525<br />
Fig. 4. Schematic representation of the MI map in the fiber system<br />
for β 2 < 0 and β 4 > 0, in which the photon reservoir is created by<br />
raising the FOD coefficient β 4.<br />
beginning of the propagation until the total emptying of the<br />
reservoir, which occurs at z∼4:2 m [as can be seen in Figs. 3<br />
(b1) and 3(b2)]. After this distance, the fiber losses cause a<br />
continual frequency drift of the si<strong>de</strong>bands.<br />
3. The power P 0¼ 0:13 W is sufficiently large for completely<br />
filling the photon reservoir. Consequently, the frequency<br />
drift of the si<strong>de</strong>bands is completely suppressed [as Figs. 3(b1)<br />
Fig. 5. Plots illustrating the MI process in the operating conditions of<br />
nonsuppression of the frequency drifts for a chalcogeni<strong>de</strong> type of fiber<br />
with parameters β 2¼−2:6 × 10 −3 ps 2 =m, β 4¼ 5 × 10 −6 ps 4 =m, and<br />
α¼1 dB=m. P 0¼ 55 mW.<br />
<br />
and 3(b2) show]. Our analytical approaches of LSA (ALSA and<br />
ELSA) are remarkably well confirmed by the direct resolution<br />
of the NLSE (1), as illustrated in Fig. 3. However, the predictions<br />
given by the ALSA become consistent only after the initial<br />
transient regime, whereas the ELSA gives excellent<br />
predictions all along the propagation distance.<br />
B. Filling of the Photon Reservoir for Fixed P 0<br />
This strategy, which is new and alternative to the one presented<br />
above, is the one that should be adopted when one<br />
does not have a laser source with tunable power. In this case,<br />
one can still achieve suppression of the frequency drifts in the<br />
MI spectra, but, there, it becomes necessary to <strong>de</strong>sign a fiber<br />
having the appropriate dispersion parameters for the given<br />
pump power P 0. Thus, another interesting version of a <strong>de</strong>vice<br />
for suppressing the frequency drifts can operate with a pump<br />
laser with fixed power, say P 0. In this case, the suppression<br />
procedure is achievable with a fiber for which the FOD coefficient<br />
is adjusted to create the photon reservoir. To this end,<br />
one can proceed in several steps.<br />
1. Having chosen a fiber length L that matches the <strong>de</strong>vice<br />
that we wish to <strong>de</strong>velop, we can then <strong>de</strong>termine the capacity<br />
of the photon reservoir as follows:<br />
Fig. 6. Plots illustrating the MI process in the operating conditions of<br />
partial suppression of the frequency drifts for a chalcogeni<strong>de</strong> type of<br />
fiber with parameters β 2¼−2:6 × 10 −3 ps 2 =m, β 4¼ 9 × 10 −6 ps 4 =m,<br />
and α¼1 dB=m. P 0¼ 55 mW.
1526 J. Opt. Soc. Am. B / Vol. 28, No. 6 / June 2011 Zambo Abou’ou et al.<br />
Fig. 7. Plots illustrating the MI process in the operating conditions of<br />
total suppression of the frequency drifts for a chalcogeni<strong>de</strong> type of<br />
fiber with parameters β 2 ¼−2:6 × 10 −3 ps 2 =m, β 4 ¼ 15 × 10 −6 ps 4 =m,<br />
and α ¼ 1 dB=m. P 0 ¼ 55 mW.<br />
R ¼ P 0½1−expð−αLÞŠ: ð31Þ<br />
2. Next, we <strong>de</strong>termine the critical value of the FOD, which<br />
we <strong>de</strong>note as β 4c1, i.e., the value of β 4 for which P 0 becomes a<br />
critical power. One can clearly observe in Fig. 4 that, by raising<br />
β 4 above β 4c1, the critical power P c1ðβ 4Þ <strong>de</strong>creases and<br />
moves away from P 0. Then, one can simply choose a<br />
coefficient β 40 such that the difference between P 0 and P c1<br />
corresponds to the capacity of the photon reservoir:<br />
P 0− P c1ðβ 40Þ ¼ R: ð32Þ<br />
By applying this procedure to a chalcogeni<strong>de</strong> type of fiber<br />
(for which the dispersion parameters are assumed adjustable<br />
in the manufacturing), we obtained the following results for<br />
an input power P 0 ¼ 55 mW.<br />
Figures 5(a) and 5(b) correspond to a situation where<br />
β 4 ¼ 5 × 10 −6 ps 4 m −1 < β 4c1 ¼ 5:3 × 10 −6 ps 4 m −1 . In this case,<br />
there is no available photon reservoir to compensate for the<br />
pump <strong>de</strong>pletion caused by the losses. Consequently, the si<strong>de</strong>bands<br />
un<strong>de</strong>rgo a frequency drift, as shown in Fig. 5(b). The<br />
lower (higher)-frequency si<strong>de</strong>bands move toward (move away<br />
from) the pump.<br />
Figures 6(a) and 6(b) correspond to a situation where β 4 is<br />
greater than β 4c1, but not large enough to create a photon<br />
reservoir of sufficient capacity to fully compensate the pump<br />
<strong>de</strong>pletion caused by the losses. Consequently, the si<strong>de</strong>band<br />
frequency remains constant until the complete emptying of<br />
the photon reservoir, which occurs at around z ¼ 4 m. Then,<br />
the si<strong>de</strong>bands execute a frequency drift as shown in Fig. 6(b).<br />
Figures 7(a) and 7(b) correspond to a situation where β 4 is<br />
greater than β 4c1 and sufficiently large to create a photon reservoir<br />
whose capacity is sufficient for fully compensating<br />
the pump <strong>de</strong>pletion caused by the losses. Consequently, the<br />
frequency drift of the si<strong>de</strong>bands is completely suppressed<br />
in the MI process as shown in Fig. 7(b).<br />
5. SMOTHERING PROCESS AND<br />
RESTORATION OF MI SIDEBANDS<br />
Of all the physical parameters of an optical fiber, the attenuation<br />
coefficient is probably one of the most sensitive to the<br />
quality of the manufacturing of the fiber. In<strong>de</strong>ed, a dramatic<br />
reduction in this coefficient can be achieved by improving the<br />
manufacturing process (e.g., via a reduction of the amount of<br />
impurities in the glass or an optimization of the amount and<br />
nature of the dopants). In fact, the values of the attenuation<br />
coefficients given in Table 1 are situated rather in the lower<br />
ranges of values of those coefficients for the fibers consi<strong>de</strong>red.<br />
It is therefore instructive to examine the impact of a<br />
substantial variation of the attenuation coefficient on the MI<br />
processes. To this end, we have represented in Fig. 8(a) the<br />
gain curves obtained with the parameters of the chalcogeni<strong>de</strong><br />
fiber of Table 1, but for different values of α and a pump power<br />
fixed at P 0 ¼ 35 mW. In particular, the comparison of the gain<br />
spectra obtained for α ¼ 1 dB=m and α ¼ 2:4 dB=m shows that<br />
Fig. 8. Plots of the gain spectra for a chalcogeni<strong>de</strong> type of fiber with<br />
dispersion parameters β 2 ¼−2:6 × 10 −3 ps 2 =m, β 4 ¼ 9 × 10 −6 ps 4 =m,<br />
and different values of the absorption parameter α.
Zambo Abou’ou et al. Vol. 28, No. 6 / June 2011 / J. Opt. Soc. Am. B 1527<br />
increasing the attenuation coefficient by a factor 2.4 causes a<br />
collapse of the gain of one or<strong>de</strong>r of magnitu<strong>de</strong>. The gain<br />
passes from about 25 dB (for α¼1 dB=m) to 2:5 dB (for<br />
α¼2:4 dB=m). This result indicates that. during the lifetime<br />
of this type of <strong>de</strong>vice, if additional losses occur acci<strong>de</strong>ntally<br />
(e.g., losses due to microbending of the fiber), they will cause<br />
a malfunction of the <strong>de</strong>vice. To cope with such a situation, it is<br />
preferable that the <strong>de</strong>vice be endowed with a pump source of<br />
tunable power. In<strong>de</strong>ed, one can observe in Fig. 8 that the drop<br />
of the MI gain caused by the increase of the attenuation coefficient<br />
from α¼1 dB=m to α¼2:4 dB=m [Fig. 8(a)] is at least<br />
partially restored by an enhancement of the pump power [as<br />
shown in Fig. 8(b)]. However, this enhancement of the pump<br />
power does not suppress the frequency drift, which must be<br />
treated by the method of photon reservoir in or<strong>de</strong>r to obtain a<br />
more efficient <strong>de</strong>vice. Finally, a <strong>de</strong>vice for generating MI with<br />
a photon reservoir and a tunable pump power will compensate<br />
any acci<strong>de</strong>ntal drop of MI gain (caused by an alteration<br />
of the attenuation parameter) via a simple increase of the<br />
power pump, which will have the enormous advantage of<br />
not causing an alteration of the si<strong>de</strong>band frequency. This property<br />
constitutes a major qualitative difference and an advantage<br />
compared to standard <strong>de</strong>vices of generation of MI, which<br />
are generally characterized by a <strong>de</strong>pen<strong>de</strong>nce of the si<strong>de</strong>band<br />
frequency upon the pump power.<br />
6. CONCLUSION<br />
The performance criteria most commonly used to evaluate the<br />
HNLF are the magnitu<strong>de</strong> of the nonlinearity coefficient and a<br />
figure of merit that can be expressed simply as the ratio between<br />
the coefficients of gain and loss. Fibers with high figure<br />
of merit (i.e., that have a high coefficient of nonlinearity and a<br />
mo<strong>de</strong>rate attenuation coefficient) are generally perceived as<br />
the most efficient. However, it is less well perceived that the<br />
gains of performance of fiber optic <strong>de</strong>vices do not increase<br />
simply in a linear fashion (and without limit) with the figure<br />
of merit. We have shown in this study of MI in HNLFs (which<br />
are also those having the highest absorption coefficients) that<br />
the loss effects are not restricted simply to a reduction the<br />
gain of performance in the processes of generation of optical<br />
frequencies. We have shown that beyond a certain level of the<br />
attenuation coefficient, si<strong>de</strong> effects may occur and <strong>de</strong>gra<strong>de</strong><br />
the MI process qualitatively. In particular, during their propagation,<br />
the MI si<strong>de</strong>bands execute a frequency drift whose magnitu<strong>de</strong><br />
<strong>de</strong>pends significantly on the value of the attenuation<br />
coefficient and the fiber length. Thus, we have shown that<br />
the factor of merit and the coefficient of nonlinearity can<br />
no longer be systematically consi<strong>de</strong>red the only major performance<br />
criteria of HNLFs. Perturbations produced intrinsically<br />
by a strong attenuation coefficient should be taken into account.<br />
We have presented a comparative study of performance<br />
of several types of nonlinear fibers, taking into<br />
account the rate of frequency drift in the performance criteria.<br />
We have found that chalcogeni<strong>de</strong> and tellurite fibers with a<br />
nonlinear refractive in<strong>de</strong>x 100 times larger than that of silica<br />
are the most competitive in the MI processes (with respect to<br />
their length, pump power requirements, and the amplitu<strong>de</strong> of<br />
the frequency drift) when their attenuation coefficients are of<br />
the or<strong>de</strong>r of or less than 1 dB=m.<br />
Our method of photon reservoir, which has the virtue of stabilizing<br />
the frequency of MI si<strong>de</strong>bands, can be used to reinforce<br />
<br />
the stability and reliability of light sources generating all optically<br />
pulse trains at ultrahigh repetition rates (well beyond the<br />
current limitations of electronic systems). The most competitive<br />
sources that have been proposed so far in the literature<br />
have achieved repetition rates that can range from a few tens<br />
of gigahertz to several terahertz, both in a configuration of<br />
<strong>de</strong>ployed fiber [6,7,36,37] and in a fiber cavity configuration<br />
[8–11,38,39]. However, most of these systems generate si<strong>de</strong>bands<br />
whose frequencies <strong>de</strong>pend on the pump power [6–9].<br />
Consequently, such systems, which are inherently sensitive<br />
to any un<strong>de</strong>sirable fluctuation of the pump power, could be stabilized<br />
by the method of photon reservoir. For example, in [9],<br />
the authors present a laser cavity that uses an 88 m fiber to produce<br />
a pulse train at a repetition rate (of the or<strong>de</strong>r of a few terahertz)<br />
that <strong>de</strong>pends clearly on the average intracavity power.<br />
In such a cavity, the use of a fiber with very high nonlinearity<br />
associated with a reservoir of photons (obtained by fitting the<br />
dispersive properties of the fiber) would enable one not only to<br />
significantly reduce the length of the fiber cavity but also to<br />
make the system insensitive to un<strong>de</strong>sirable fluctuations of<br />
the intracavity power. On the other hand, although realization<br />
of the photon reservoir requires an adjustment of the dispersive<br />
properties of the fiber up to or<strong>de</strong>r four, technologies for <strong>de</strong>signing<br />
and manufacturing such fibers are currently available. In<br />
our analysis, although we have explicitly displayed the term<br />
of saturation of the nonlinearity, realization of the photon reservoir<br />
does not require that the system operates in the regime<br />
of saturation of the nonlinearity (i.e., with the two branches of<br />
the critical powers). The system can perfectly operate with the<br />
usual Kerr nonlinearity (i.e., with only one branch of the critical<br />
powers). Finally, we have shown that when HNLFs are<br />
exploited with a photon reservoir, they take a <strong>de</strong>cisive advantage<br />
over the standard silica fibers and that, in addition, the use<br />
of a tunable pump power offers the possibility of regenerating<br />
the MI si<strong>de</strong>bands in case of acci<strong>de</strong>ntal alterations of the attenuation<br />
coefficient of the fiber. Hence, the ability of our system<br />
for generating waves at stable and perfectly controlled<br />
frequencies is a key property in many practical applications,<br />
such as the generation of new optical frequencies or the generation<br />
of ultrafast pulse trains for optical communications.<br />
ACKNOWLEDGMENTS<br />
M. N. Zambo and C. M. Ngabireng wish to thank the<br />
Laboratoire ICB for their hospitality. M. N. Zambo thanks<br />
the Cameroon government for financial assistance.<br />
REFERENCES<br />
1. G. P. Agrawal, Nonlinear Fiber Optics, 4th ed. (Aca<strong>de</strong>mic,<br />
2008).<br />
2. A. Hasegawa, “Generation of a train of soliton pulses by induced<br />
modulational instability in optical fibers,” Opt. Lett. 9, 288–<br />
290 (1984).<br />
3. S. K. Turitsyn, A. M. Rubenchik, and M. P. Fedoruk, “On the<br />
theory of the modulation instability in optical fiber amplifiers,”<br />
Opt. Lett. 35, 2684–2686 (2010).<br />
4. A. M. Rubenchik, S. K. Turitsyn, and M. P. Fedoruk, “Modulation<br />
instability in high power laser amplifiers,” Opt. Express 18,<br />
1380–1388 (2010).<br />
5. M. Karlson, “Modulational instability in lossy optical fiber,”<br />
J. Opt. Soc. Am. B 12, 2071–2077 (1995).<br />
6. A. Hasegawa and W. F. Brinkman, “Tunable coherent ir and fir<br />
sources utilizing modulational instability,” IEEE J. Quantum<br />
Electron. 16, 694–697 (1980).
1528 J. Opt. Soc. Am. B / Vol. 28, No. 6 / June 2011 Zambo Abou’ou et al.<br />
7. M. J. Potasek and G. P. Agrawal, “Self-amplitu<strong>de</strong>-modulation of<br />
optical pulses in nonlinear dispersive fibers,” Phys. Rev. A 36,<br />
3862–3867 (1987).<br />
8. M. Nakazawa, K. Suzuki, and H. A. Haus, “The modulational<br />
instability laser. I. Experiment,” IEEE J. Quantum Electron.<br />
25, 2036–2044 (1989).<br />
9. P. Franco, F. Fontana, I. Cristiani, M. Midrio, and M. Romagnoli,<br />
“Self-induced modulational-instability laser,” Opt. Lett. 20,<br />
2009–2011 (1995).<br />
10. S. Coen and M. Haelterman, “Continuous-wave ultrahighrepetition-rate<br />
pulse-train generation through modulational instability<br />
in a passive fiber cavity,” Opt. Lett. 26, 39–41 (2001).<br />
11. T. Sylvestre, S. Coen, P. Emplit, and M. Haelterman, “Self-induced<br />
modulational instability laser revisited: normal dispersion and<br />
dark-pulse train generation,” Opt. Lett. 27, 482–484 (2002).<br />
12. A. Labruyere, S. Ambomo, C. Ngabireng, P. Tchofo Dinda,<br />
K. Nakkeeran, and K. Porsezian, “Suppression of si<strong>de</strong>band<br />
frequency shifts in the modulational instability spectra of wave<br />
propagation in optical fiber systems,” Opt. Lett. 32, 1287–<br />
1289 (2007).<br />
13. R. K. Jain and R. C. Lind, “Degenerate four-wave mixing in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. 73, 647–653 (1983).<br />
14. L. H. Acioli, A. S. L. Gomes, and J. R. R. Leite, “Measurement of<br />
high-or<strong>de</strong>r optical nonlinear susceptibilities in semiconductordoped<br />
glasses,” Appl. Phys. Lett. 53, 1788–1790 (1988).<br />
15. U. Langebein, F. Le<strong>de</strong>rer, T. Peschel, and H. E. Ponath, “Nonlinear<br />
gui<strong>de</strong>d waves in saturable nonlinear media,” Opt. Lett.<br />
10, 571–573 (1985).<br />
16. P. Roussignol, D. Ricard, J. Lukasik, and C. Flytzanis, “New<br />
results on optical phase conjugation in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. B 4, 5–13 (1987).<br />
17. C. N. Ironsi<strong>de</strong>, T. J. Cullen, B. S. Bhumbra, J. Bell, W. C. Banyai,<br />
N. Finlayson, C. T. Seaton, and G. I. Stegeman, “Nonlinearoptical<br />
effects in ion-exchanged semiconductor-doped glass<br />
wavegui<strong>de</strong>s,” J. Opt. Soc. Am. B 5, 492–495 (1988).<br />
18. J. L. Coutaz and M. Kull, “Saturation of nonlinear in<strong>de</strong>x of<br />
refraction in semiconductor-doped glass,” J. Opt. Soc. Am. B<br />
8, 95–98 (1991).<br />
19. X. H. Wang and G. K. Cambrell, “Simulation of strong nonlinear<br />
effects in optical wavegui<strong>de</strong>s,” J. Opt. Soc. Am. B 10,<br />
2048–2055 (1993).<br />
20. D. W. Hall, M. A. Newhouse, N. F. Borrelli, W. H. Dumbaugh, and<br />
D. L. Weidman, “Nonlinear optical susceptibilities of high-in<strong>de</strong>x<br />
glasses,” Appl. Phys. Lett. 54, 1293–1295 (1989).<br />
21. I. Kang, T. D. Krauss, F. W. Wise, B. G. Aitken, and N. F. Borrelli,<br />
“Femtosecond measurement of enhanced optical nonlinearities<br />
of sulphi<strong>de</strong> glasses and heavy-metal-doped oxi<strong>de</strong> glasses,” J.<br />
Opt. Soc. Am. B 12, 2053–2059 (1995).<br />
22. Y. F. Chen, K. Beckwitt, F. K. Wise, B. G. Aitken, J. S. Sanghera,<br />
and I. D. Aggarwal, “Measurement of fifth- and seventh-or<strong>de</strong>r<br />
nonlinearities of glasses,” J. Opt. Soc. Am. B 23, 347–352 (2006).<br />
23. M. N. Zambo Abou’ou, P. Tchofo Dinda, C. M. Ngabireng, B.<br />
Kibler, F. Smektala, and K. Porsezian, “Suppression of the<br />
frequency drift of modulational instability si<strong>de</strong>bands by means<br />
of a fiber system associated with a photon reservoir,” Opt. Lett.<br />
36, 256–258 (2011).<br />
24. P. Tchofo Dinda, and K. Porsezian, “Impact of fourth-or<strong>de</strong>r<br />
dispersion in the modulational instability spectra of wave<br />
propagation in glass fibers with saturable nonlinearity,” J.<br />
Opt. Soc. Am. B 27, 1143–1152 (2010).<br />
25. S. B. Cavalcanti, J. C. Cressoni, H. R. da Cruz, and A. S. Gouveia-<br />
Neto, “Modulation instability in the region of minimum groupvelocity<br />
dispersion of single-mo<strong>de</strong> optical fibers via an exten<strong>de</strong>d<br />
nonlinear Schrodinger equation,” Phys. Rev. A 43, 6162–6165<br />
(1991).<br />
26. J. H. Chou and R. Wu, “A generalization of the frobenius method<br />
for ordinary differential equations with regular singular points,”<br />
J. Math. Stat. 1, 3–7 (2005).<br />
27. A. Ferrando, E. Silvestre, J. J. Miret, and P. Andres, “Nearly zero<br />
ultraflattened dispersion in photonic crystal fibers,” Opt. Lett.<br />
25, 790–792 (2000).<br />
28. T. A. Birks, W. J. Wadsworth, and P. St. J. Russell, “Supercontinuum<br />
generation in tapered fibers,” Opt. Lett. 25, 1415–1417<br />
(2000).<br />
29. S. G. Leon-Saval, T. A. Birks, W. J. Wadsworth, and P. St. J.<br />
Russell, “Supercontinuum generation in submicron fibre wavegui<strong>de</strong>s,”<br />
Opt. Express 12, 2864–2869 (2004).<br />
30. V. V. Ravi Kanth Kumar, A. George, and P. Russel,<br />
“Tellurite photonic crystal fiber,” Opt. Express 11, 2641–2645<br />
(2003).<br />
31. L. Brilland, F. Smektala, G. Renversez, T. Chartier, J. Troles, T.<br />
N. Nguyen, N. Traynor, and A. Monteville, “Fabrication of<br />
complex structures of holey fibers in chalcogeni<strong>de</strong> glass,”<br />
Opt. Express 14, 1280–1285 (2006).<br />
32. C. Chaudhari, T. Suzuki, and Y. Ohishi, “Design of zero<br />
chromatic dispersion chalcogeni<strong>de</strong> As 2S 3 glass nanofibers,” J.<br />
Lightwave Technol. 27, 2095–2099 (2009).<br />
33. A. W. Sny<strong>de</strong>r and J. D. Love, Optical Wavegui<strong>de</strong> Theory<br />
(Chapman and Hall, 1983).<br />
34. M. El-Amraoui, J. Fatome, J. C. Jules, B. Kibler, G. Gadret,<br />
C. Fortier, F. Smektala, I. Skripatchev, C. F. Polacchini, Y.<br />
Messad<strong>de</strong>q, J. Troles, L. Brilland, M. Szpulak, and G. Renversez,<br />
“Strong infrared spectral broa<strong>de</strong>ning in low-loss As-S chalcogeni<strong>de</strong><br />
suspen<strong>de</strong>d core microstructured optical fibers,” Opt.<br />
Express 18, 4547–4556 (2010).<br />
35. M. Liao, C. Chaudhari, G. Qin, X. Yan, C. Kito, T. Suzuki, Y.<br />
Ohishi, M. Matsumoto, and T. Misumi, “Fabrication and characterization<br />
of a chalcogeni<strong>de</strong>-tellurite composite microstructure<br />
fiber with high nonlinearity,” Opt. Express 17, 21608–21614<br />
(2009).<br />
36. K. Tai, A. Tomita, J. L. Jewell, and A. Hasegawa, “Generation of<br />
subpicosecond solitonlike optical pulses at 0:3 thz repetition<br />
rate by induced modulational instability,” Appl. Phys. Lett.<br />
236–238 (1986).<br />
37. P. V. Mamyshev, S. V. Chernikov, E. M. Dianov, and A. M.<br />
Prokhorov, “Generation of a high-repetition-rate train of practically<br />
noninteracting solitons by using the induced modulational<br />
instability and Raman self scattering effects,” Opt. Lett. 15,<br />
1365–1367 (1990).<br />
38. C. J. S. Matos, D. A. Chestnut, and J. R. Taylor, “Low-threshold<br />
self-induced modulational instability ring laser in highly nonlinear<br />
fiber yielding a continuous-wave 262 ghz soliton train,”<br />
Opt. Lett. 27, 915–917 (2002).<br />
39. Y. Gong, P. Shum, D. Tang, C. Lu, and X. Guo, “660 ghz solitons<br />
source based on modulation instability in short cavity,” Opt.<br />
Express 11, 2480–2485 (2003).
1528 J. Opt. Soc. Am. B / Vol. 28, No. 6 / June 2011 Zambo Abou’ou et al.<br />
7. M. J. Potasek and G. P. Agrawal, “Self-amplitu<strong>de</strong>-modulation of<br />
optical pulses in nonlinear dispersive fibers,” Phys. Rev. A 36,<br />
3862–3867 (1987).<br />
8. M. Nakazawa, K. Suzuki, and H. A. Haus, “The modulational<br />
instability laser. I. Experiment,” IEEE J. Quantum Electron.<br />
25, 2036–2044 (1989).<br />
9. P. Franco, F. Fontana, I. Cristiani, M. Midrio, and M. Romagnoli,<br />
“Self-induced modulational-instability laser,” Opt. Lett. 20,<br />
2009–2011 (1995).<br />
10. S. Coen and M. Haelterman, “Continuous-wave ultrahighrepetition-rate<br />
pulse-train generation through modulational instability<br />
in a passive fiber cavity,” Opt. Lett. 26, 39–41 (2001).<br />
11. T. Sylvestre, S. Coen, P. Emplit, and M. Haelterman, “Self-induced<br />
modulational instability laser revisited: normal dispersion and<br />
dark-pulse train generation,” Opt. Lett. 27, 482–484 (2002).<br />
12. A. Labruyere, S. Ambomo, C. Ngabireng, P. Tchofo Dinda,<br />
K. Nakkeeran, and K. Porsezian, “Suppression of si<strong>de</strong>band<br />
frequency shifts in the modulational instability spectra of wave<br />
propagation in optical fiber systems,” Opt. Lett. 32, 1287–<br />
1289 (2007).<br />
13. R. K. Jain and R. C. Lind, “Degenerate four-wave mixing in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. 73, 647–653 (1983).<br />
14. L. H. Acioli, A. S. L. Gomes, and J. R. R. Leite, “Measurement of<br />
high-or<strong>de</strong>r optical nonlinear susceptibilities in semiconductordoped<br />
glasses,” Appl. Phys. Lett. 53, 1788–1790 (1988).<br />
15. U. Langebein, F. Le<strong>de</strong>rer, T. Peschel, and H. E. Ponath, “Nonlinear<br />
gui<strong>de</strong>d waves in saturable nonlinear media,” Opt. Lett.<br />
10, 571–573 (1985).<br />
16. P. Roussignol, D. Ricard, J. Lukasik, and C. Flytzanis, “New<br />
results on optical phase conjugation in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. B 4, 5–13 (1987).<br />
17. C. N. Ironsi<strong>de</strong>, T. J. Cullen, B. S. Bhumbra, J. Bell, W. C. Banyai,<br />
N. Finlayson, C. T. Seaton, and G. I. Stegeman, “Nonlinearoptical<br />
effects in ion-exchanged semiconductor-doped glass<br />
wavegui<strong>de</strong>s,” J. Opt. Soc. Am. B 5, 492–495 (1988).<br />
18. J. L. Coutaz and M. Kull, “Saturation of nonlinear in<strong>de</strong>x of<br />
refraction in semiconductor-doped glass,” J. Opt. Soc. Am. B<br />
8, 95–98 (1991).<br />
19. X. H. Wang and G. K. Cambrell, “Simulation of strong nonlinear<br />
effects in optical wavegui<strong>de</strong>s,” J. Opt. Soc. Am. B 10,<br />
2048–2055 (1993).<br />
20. D. W. Hall, M. A. Newhouse, N. F. Borrelli, W. H. Dumbaugh, and<br />
D. L. Weidman, “Nonlinear optical susceptibilities of high-in<strong>de</strong>x<br />
glasses,” Appl. Phys. Lett. 54, 1293–1295 (1989).<br />
21. I. Kang, T. D. Krauss, F. W. Wise, B. G. Aitken, and N. F. Borrelli,<br />
“Femtosecond measurement of enhanced optical nonlinearities<br />
of sulphi<strong>de</strong> glasses and heavy-metal-doped oxi<strong>de</strong> glasses,” J.<br />
Opt. Soc. Am. B 12, 2053–2059 (1995).<br />
22. Y. F. Chen, K. Beckwitt, F. K. Wise, B. G. Aitken, J. S. Sanghera,<br />
and I. D. Aggarwal, “Measurement of fifth- and seventh-or<strong>de</strong>r<br />
nonlinearities of glasses,” J. Opt. Soc. Am. B 23, 347–352 (2006).<br />
23. M. N. Zambo Abou’ou, P. Tchofo Dinda, C. M. Ngabireng, B.<br />
Kibler, F. Smektala, and K. Porsezian, “Suppression of the<br />
frequency drift of modulational instability si<strong>de</strong>bands by means<br />
of a fiber system associated with a photon reservoir,” Opt. Lett.<br />
36, 256–258 (2011).<br />
24. P. Tchofo Dinda, and K. Porsezian, “Impact of fourth-or<strong>de</strong>r<br />
dispersion in the modulational instability spectra of wave<br />
propagation in glass fibers with saturable nonlinearity,” J.<br />
Opt. Soc. Am. B 27, 1143–1152 (2010).<br />
25. S. B. Cavalcanti, J. C. Cressoni, H. R. da Cruz, and A. S. Gouveia-<br />
Neto, “Modulation instability in the region of minimum groupvelocity<br />
dispersion of single-mo<strong>de</strong> optical fibers via an exten<strong>de</strong>d<br />
nonlinear Schrodinger equation,” Phys. Rev. A 43, 6162–6165<br />
(1991).<br />
26. J. H. Chou and R. Wu, “A generalization of the frobenius method<br />
for ordinary differential equations with regular singular points,”<br />
J. Math. Stat. 1, 3–7 (2005).<br />
27. A. Ferrando, E. Silvestre, J. J. Miret, and P. Andres, “Nearly zero<br />
ultraflattened dispersion in photonic crystal fibers,” Opt. Lett.<br />
25, 790–792 (2000).<br />
28. T. A. Birks, W. J. Wadsworth, and P. St. J. Russell, “Supercontinuum<br />
generation in tapered fibers,” Opt. Lett. 25, 1415–1417<br />
(2000).<br />
29. S. G. Leon-Saval, T. A. Birks, W. J. Wadsworth, and P. St. J.<br />
Russell, “Supercontinuum generation in submicron fibre wavegui<strong>de</strong>s,”<br />
Opt. Express 12, 2864–2869 (2004).<br />
30. V. V. Ravi Kanth Kumar, A. George, and P. Russel,<br />
“Tellurite photonic crystal fiber,” Opt. Express 11, 2641–2645<br />
(2003).<br />
31. L. Brilland, F. Smektala, G. Renversez, T. Chartier, J. Troles, T.<br />
N. Nguyen, N. Traynor, and A. Monteville, “Fabrication of<br />
complex structures of holey fibers in chalcogeni<strong>de</strong> glass,”<br />
Opt. Express 14, 1280–1285 (2006).<br />
32. C. Chaudhari, T. Suzuki, and Y. Ohishi, “Design of zero<br />
chromatic dispersion chalcogeni<strong>de</strong> As 2S 3 glass nanofibers,” J.<br />
Lightwave Technol. 27, 2095–2099 (2009).<br />
33. A. W. Sny<strong>de</strong>r and J. D. Love, Optical Wavegui<strong>de</strong> Theory<br />
(Chapman and Hall, 1983).<br />
34. M. El-Amraoui, J. Fatome, J. C. Jules, B. Kibler, G. Gadret,<br />
C. Fortier, F. Smektala, I. Skripatchev, C. F. Polacchini, Y.<br />
Messad<strong>de</strong>q, J. Troles, L. Brilland, M. Szpulak, and G. Renversez,<br />
“Strong infrared spectral broa<strong>de</strong>ning in low-loss As-S chalcogeni<strong>de</strong><br />
suspen<strong>de</strong>d core microstructured optical fibers,” Opt.<br />
Express 18, 4547–4556 (2010).<br />
35. M. Liao, C. Chaudhari, G. Qin, X. Yan, C. Kito, T. Suzuki, Y.<br />
Ohishi, M. Matsumoto, and T. Misumi, “Fabrication and characterization<br />
of a chalcogeni<strong>de</strong>-tellurite composite microstructure<br />
fiber with high nonlinearity,” Opt. Express 17, 21608–21614<br />
(2009).<br />
36. K. Tai, A. Tomita, J. L. Jewell, and A. Hasegawa, “Generation of<br />
subpicosecond solitonlike optical pulses at 0:3 thz repetition<br />
rate by induced modulational instability,” Appl. Phys. Lett.<br />
236–238 (1986).<br />
37. P. V. Mamyshev, S. V. Chernikov, E. M. Dianov, and A. M.<br />
Prokhorov, “Generation of a high-repetition-rate train of practically<br />
noninteracting solitons by using the induced modulational<br />
instability and Raman self scattering effects,” Opt. Lett. 15,<br />
1365–1367 (1990).<br />
38. C. J. S. Matos, D. A. Chestnut, and J. R. Taylor, “Low-threshold<br />
self-induced modulational instability ring laser in highly nonlinear<br />
fiber yielding a continuous-wave 262 ghz soliton train,”<br />
Opt. Lett. 27, 915–917 (2002).<br />
39. Y. Gong, P. Shum, D. Tang, C. Lu, and X. Guo, “660 ghz solitons<br />
source based on modulation instability in short cavity,” Opt.<br />
Express 11, 2480–2485 (2003).
1528 J. Opt. Soc. Am. B / Vol. 28, No. 6 / June 2011 Zambo Abou’ou et al.<br />
7. M. J. Potasek and G. P. Agrawal, “Self-amplitu<strong>de</strong>-modulation of<br />
optical pulses in nonlinear dispersive fibers,” Phys. Rev. A 36,<br />
3862–3867 (1987).<br />
8. M. Nakazawa, K. Suzuki, and H. A. Haus, “The modulational<br />
instability laser. I. Experiment,” IEEE J. Quantum Electron.<br />
25, 2036–2044 (1989).<br />
9. P. Franco, F. Fontana, I. Cristiani, M. Midrio, and M. Romagnoli,<br />
“Self-induced modulational-instability laser,” Opt. Lett. 20,<br />
2009–2011 (1995).<br />
10. S. Coen and M. Haelterman, “Continuous-wave ultrahighrepetition-rate<br />
pulse-train generation through modulational instability<br />
in a passive fiber cavity,” Opt. Lett. 26, 39–41 (2001).<br />
11. T. Sylvestre, S. Coen, P. Emplit, and M. Haelterman, “Self-induced<br />
modulational instability laser revisited: normal dispersion and<br />
dark-pulse train generation,” Opt. Lett. 27, 482–484 (2002).<br />
12. A. Labruyere, S. Ambomo, C. Ngabireng, P. Tchofo Dinda,<br />
K. Nakkeeran, and K. Porsezian, “Suppression of si<strong>de</strong>band<br />
frequency shifts in the modulational instability spectra of wave<br />
propagation in optical fiber systems,” Opt. Lett. 32, 1287–<br />
1289 (2007).<br />
13. R. K. Jain and R. C. Lind, “Degenerate four-wave mixing in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. 73, 647–653 (1983).<br />
14. L. H. Acioli, A. S. L. Gomes, and J. R. R. Leite, “Measurement of<br />
high-or<strong>de</strong>r optical nonlinear susceptibilities in semiconductordoped<br />
glasses,” Appl. Phys. Lett. 53, 1788–1790 (1988).<br />
15. U. Langebein, F. Le<strong>de</strong>rer, T. Peschel, and H. E. Ponath, “Nonlinear<br />
gui<strong>de</strong>d waves in saturable nonlinear media,” Opt. Lett.<br />
10, 571–573 (1985).<br />
16. P. Roussignol, D. Ricard, J. Lukasik, and C. Flytzanis, “New<br />
results on optical phase conjugation in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. B 4, 5–13 (1987).<br />
17. C. N. Ironsi<strong>de</strong>, T. J. Cullen, B. S. Bhumbra, J. Bell, W. C. Banyai,<br />
N. Finlayson, C. T. Seaton, and G. I. Stegeman, “Nonlinearoptical<br />
effects in ion-exchanged semiconductor-doped glass<br />
wavegui<strong>de</strong>s,” J. Opt. Soc. Am. B 5, 492–495 (1988).<br />
18. J. L. Coutaz and M. Kull, “Saturation of nonlinear in<strong>de</strong>x of<br />
refraction in semiconductor-doped glass,” J. Opt. Soc. Am. B<br />
8, 95–98 (1991).<br />
19. X. H. Wang and G. K. Cambrell, “Simulation of strong nonlinear<br />
effects in optical wavegui<strong>de</strong>s,” J. Opt. Soc. Am. B 10,<br />
2048–2055 (1993).<br />
20. D. W. Hall, M. A. Newhouse, N. F. Borrelli, W. H. Dumbaugh, and<br />
D. L. Weidman, “Nonlinear optical susceptibilities of high-in<strong>de</strong>x<br />
glasses,” Appl. Phys. Lett. 54, 1293–1295 (1989).<br />
21. I. Kang, T. D. Krauss, F. W. Wise, B. G. Aitken, and N. F. Borrelli,<br />
“Femtosecond measurement of enhanced optical nonlinearities<br />
of sulphi<strong>de</strong> glasses and heavy-metal-doped oxi<strong>de</strong> glasses,” J.<br />
Opt. Soc. Am. B 12, 2053–2059 (1995).<br />
22. Y. F. Chen, K. Beckwitt, F. K. Wise, B. G. Aitken, J. S. Sanghera,<br />
and I. D. Aggarwal, “Measurement of fifth- and seventh-or<strong>de</strong>r<br />
nonlinearities of glasses,” J. Opt. Soc. Am. B 23, 347–352 (2006).<br />
23. M. N. Zambo Abou’ou, P. Tchofo Dinda, C. M. Ngabireng, B.<br />
Kibler, F. Smektala, and K. Porsezian, “Suppression of the<br />
frequency drift of modulational instability si<strong>de</strong>bands by means<br />
of a fiber system associated with a photon reservoir,” Opt. Lett.<br />
36, 256–258 (2011).<br />
24. P. Tchofo Dinda, and K. Porsezian, “Impact of fourth-or<strong>de</strong>r<br />
dispersion in the modulational instability spectra of wave<br />
propagation in glass fibers with saturable nonlinearity,” J.<br />
Opt. Soc. Am. B 27, 1143–1152 (2010).<br />
25. S. B. Cavalcanti, J. C. Cressoni, H. R. da Cruz, and A. S. Gouveia-<br />
Neto, “Modulation instability in the region of minimum groupvelocity<br />
dispersion of single-mo<strong>de</strong> optical fibers via an exten<strong>de</strong>d<br />
nonlinear Schrodinger equation,” Phys. Rev. A 43, 6162–6165<br />
(1991).<br />
26. J. H. Chou and R. Wu, “A generalization of the frobenius method<br />
for ordinary differential equations with regular singular points,”<br />
J. Math. Stat. 1, 3–7 (2005).<br />
27. A. Ferrando, E. Silvestre, J. J. Miret, and P. Andres, “Nearly zero<br />
ultraflattened dispersion in photonic crystal fibers,” Opt. Lett.<br />
25, 790–792 (2000).<br />
28. T. A. Birks, W. J. Wadsworth, and P. St. J. Russell, “Supercontinuum<br />
generation in tapered fibers,” Opt. Lett. 25, 1415–1417<br />
(2000).<br />
29. S. G. Leon-Saval, T. A. Birks, W. J. Wadsworth, and P. St. J.<br />
Russell, “Supercontinuum generation in submicron fibre wavegui<strong>de</strong>s,”<br />
Opt. Express 12, 2864–2869 (2004).<br />
30. V. V. Ravi Kanth Kumar, A. George, and P. Russel,<br />
“Tellurite photonic crystal fiber,” Opt. Express 11, 2641–2645<br />
(2003).<br />
31. L. Brilland, F. Smektala, G. Renversez, T. Chartier, J. Troles, T.<br />
N. Nguyen, N. Traynor, and A. Monteville, “Fabrication of<br />
complex structures of holey fibers in chalcogeni<strong>de</strong> glass,”<br />
Opt. Express 14, 1280–1285 (2006).<br />
32. C. Chaudhari, T. Suzuki, and Y. Ohishi, “Design of zero<br />
chromatic dispersion chalcogeni<strong>de</strong> As 2S 3 glass nanofibers,” J.<br />
Lightwave Technol. 27, 2095–2099 (2009).<br />
33. A. W. Sny<strong>de</strong>r and J. D. Love, Optical Wavegui<strong>de</strong> Theory<br />
(Chapman and Hall, 1983).<br />
34. M. El-Amraoui, J. Fatome, J. C. Jules, B. Kibler, G. Gadret,<br />
C. Fortier, F. Smektala, I. Skripatchev, C. F. Polacchini, Y.<br />
Messad<strong>de</strong>q, J. Troles, L. Brilland, M. Szpulak, and G. Renversez,<br />
“Strong infrared spectral broa<strong>de</strong>ning in low-loss As-S chalcogeni<strong>de</strong><br />
suspen<strong>de</strong>d core microstructured optical fibers,” Opt.<br />
Express 18, 4547–4556 (2010).<br />
35. M. Liao, C. Chaudhari, G. Qin, X. Yan, C. Kito, T. Suzuki, Y.<br />
Ohishi, M. Matsumoto, and T. Misumi, “Fabrication and characterization<br />
of a chalcogeni<strong>de</strong>-tellurite composite microstructure<br />
fiber with high nonlinearity,” Opt. Express 17, 21608–21614<br />
(2009).<br />
36. K. Tai, A. Tomita, J. L. Jewell, and A. Hasegawa, “Generation of<br />
subpicosecond solitonlike optical pulses at 0:3 thz repetition<br />
rate by induced modulational instability,” Appl. Phys. Lett.<br />
236–238 (1986).<br />
37. P. V. Mamyshev, S. V. Chernikov, E. M. Dianov, and A. M.<br />
Prokhorov, “Generation of a high-repetition-rate train of practically<br />
noninteracting solitons by using the induced modulational<br />
instability and Raman self scattering effects,” Opt. Lett. 15,<br />
1365–1367 (1990).<br />
38. C. J. S. Matos, D. A. Chestnut, and J. R. Taylor, “Low-threshold<br />
self-induced modulational instability ring laser in highly nonlinear<br />
fiber yielding a continuous-wave 262 ghz soliton train,”<br />
Opt. Lett. 27, 915–917 (2002).<br />
39. Y. Gong, P. Shum, D. Tang, C. Lu, and X. Guo, “660 ghz solitons<br />
source based on modulation instability in short cavity,” Opt.<br />
Express 11, 2480–2485 (2003).
1528 J. Opt. Soc. Am. B / Vol. 28, No. 6 / June 2011 Zambo Abou’ou et al.<br />
7. M. J. Potasek and G. P. Agrawal, “Self-amplitu<strong>de</strong>-modulation of<br />
optical pulses in nonlinear dispersive fibers,” Phys. Rev. A 36,<br />
3862–3867 (1987).<br />
8. M. Nakazawa, K. Suzuki, and H. A. Haus, “The modulational<br />
instability laser. I. Experiment,” IEEE J. Quantum Electron.<br />
25, 2036–2044 (1989).<br />
9. P. Franco, F. Fontana, I. Cristiani, M. Midrio, and M. Romagnoli,<br />
“Self-induced modulational-instability laser,” Opt. Lett. 20,<br />
2009–2011 (1995).<br />
10. S. Coen and M. Haelterman, “Continuous-wave ultrahighrepetition-rate<br />
pulse-train generation through modulational instability<br />
in a passive fiber cavity,” Opt. Lett. 26, 39–41 (2001).<br />
11. T. Sylvestre, S. Coen, P. Emplit, and M. Haelterman, “Self-induced<br />
modulational instability laser revisited: normal dispersion and<br />
dark-pulse train generation,” Opt. Lett. 27, 482–484 (2002).<br />
12. A. Labruyere, S. Ambomo, C. Ngabireng, P. Tchofo Dinda,<br />
K. Nakkeeran, and K. Porsezian, “Suppression of si<strong>de</strong>band<br />
frequency shifts in the modulational instability spectra of wave<br />
propagation in optical fiber systems,” Opt. Lett. 32, 1287–<br />
1289 (2007).<br />
13. R. K. Jain and R. C. Lind, “Degenerate four-wave mixing in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. 73, 647–653 (1983).<br />
14. L. H. Acioli, A. S. L. Gomes, and J. R. R. Leite, “Measurement of<br />
high-or<strong>de</strong>r optical nonlinear susceptibilities in semiconductordoped<br />
glasses,” Appl. Phys. Lett. 53, 1788–1790 (1988).<br />
15. U. Langebein, F. Le<strong>de</strong>rer, T. Peschel, and H. E. Ponath, “Nonlinear<br />
gui<strong>de</strong>d waves in saturable nonlinear media,” Opt. Lett.<br />
10, 571–573 (1985).<br />
16. P. Roussignol, D. Ricard, J. Lukasik, and C. Flytzanis, “New<br />
results on optical phase conjugation in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. B 4, 5–13 (1987).<br />
17. C. N. Ironsi<strong>de</strong>, T. J. Cullen, B. S. Bhumbra, J. Bell, W. C. Banyai,<br />
N. Finlayson, C. T. Seaton, and G. I. Stegeman, “Nonlinearoptical<br />
effects in ion-exchanged semiconductor-doped glass<br />
wavegui<strong>de</strong>s,” J. Opt. Soc. Am. B 5, 492–495 (1988).<br />
18. J. L. Coutaz and M. Kull, “Saturation of nonlinear in<strong>de</strong>x of<br />
refraction in semiconductor-doped glass,” J. Opt. Soc. Am. B<br />
8, 95–98 (1991).<br />
19. X. H. Wang and G. K. Cambrell, “Simulation of strong nonlinear<br />
effects in optical wavegui<strong>de</strong>s,” J. Opt. Soc. Am. B 10,<br />
2048–2055 (1993).<br />
20. D. W. Hall, M. A. Newhouse, N. F. Borrelli, W. H. Dumbaugh, and<br />
D. L. Weidman, “Nonlinear optical susceptibilities of high-in<strong>de</strong>x<br />
glasses,” Appl. Phys. Lett. 54, 1293–1295 (1989).<br />
21. I. Kang, T. D. Krauss, F. W. Wise, B. G. Aitken, and N. F. Borrelli,<br />
“Femtosecond measurement of enhanced optical nonlinearities<br />
of sulphi<strong>de</strong> glasses and heavy-metal-doped oxi<strong>de</strong> glasses,” J.<br />
Opt. Soc. Am. B 12, 2053–2059 (1995).<br />
22. Y. F. Chen, K. Beckwitt, F. K. Wise, B. G. Aitken, J. S. Sanghera,<br />
and I. D. Aggarwal, “Measurement of fifth- and seventh-or<strong>de</strong>r<br />
nonlinearities of glasses,” J. Opt. Soc. Am. B 23, 347–352 (2006).<br />
23. M. N. Zambo Abou’ou, P. Tchofo Dinda, C. M. Ngabireng, B.<br />
Kibler, F. Smektala, and K. Porsezian, “Suppression of the<br />
frequency drift of modulational instability si<strong>de</strong>bands by means<br />
of a fiber system associated with a photon reservoir,” Opt. Lett.<br />
36, 256–258 (2011).<br />
24. P. Tchofo Dinda, and K. Porsezian, “Impact of fourth-or<strong>de</strong>r<br />
dispersion in the modulational instability spectra of wave<br />
propagation in glass fibers with saturable nonlinearity,” J.<br />
Opt. Soc. Am. B 27, 1143–1152 (2010).<br />
25. S. B. Cavalcanti, J. C. Cressoni, H. R. da Cruz, and A. S. Gouveia-<br />
Neto, “Modulation instability in the region of minimum groupvelocity<br />
dispersion of single-mo<strong>de</strong> optical fibers via an exten<strong>de</strong>d<br />
nonlinear Schrodinger equation,” Phys. Rev. A 43, 6162–6165<br />
(1991).<br />
26. J. H. Chou and R. Wu, “A generalization of the frobenius method<br />
for ordinary differential equations with regular singular points,”<br />
J. Math. Stat. 1, 3–7 (2005).<br />
27. A. Ferrando, E. Silvestre, J. J. Miret, and P. Andres, “Nearly zero<br />
ultraflattened dispersion in photonic crystal fibers,” Opt. Lett.<br />
25, 790–792 (2000).<br />
28. T. A. Birks, W. J. Wadsworth, and P. St. J. Russell, “Supercontinuum<br />
generation in tapered fibers,” Opt. Lett. 25, 1415–1417<br />
(2000).<br />
29. S. G. Leon-Saval, T. A. Birks, W. J. Wadsworth, and P. St. J.<br />
Russell, “Supercontinuum generation in submicron fibre wavegui<strong>de</strong>s,”<br />
Opt. Express 12, 2864–2869 (2004).<br />
30. V. V. Ravi Kanth Kumar, A. George, and P. Russel,<br />
“Tellurite photonic crystal fiber,” Opt. Express 11, 2641–2645<br />
(2003).<br />
31. L. Brilland, F. Smektala, G. Renversez, T. Chartier, J. Troles, T.<br />
N. Nguyen, N. Traynor, and A. Monteville, “Fabrication of<br />
complex structures of holey fibers in chalcogeni<strong>de</strong> glass,”<br />
Opt. Express 14, 1280–1285 (2006).<br />
32. C. Chaudhari, T. Suzuki, and Y. Ohishi, “Design of zero<br />
chromatic dispersion chalcogeni<strong>de</strong> As 2S 3 glass nanofibers,” J.<br />
Lightwave Technol. 27, 2095–2099 (2009).<br />
33. A. W. Sny<strong>de</strong>r and J. D. Love, Optical Wavegui<strong>de</strong> Theory<br />
(Chapman and Hall, 1983).<br />
34. M. El-Amraoui, J. Fatome, J. C. Jules, B. Kibler, G. Gadret,<br />
C. Fortier, F. Smektala, I. Skripatchev, C. F. Polacchini, Y.<br />
Messad<strong>de</strong>q, J. Troles, L. Brilland, M. Szpulak, and G. Renversez,<br />
“Strong infrared spectral broa<strong>de</strong>ning in low-loss As-S chalcogeni<strong>de</strong><br />
suspen<strong>de</strong>d core microstructured optical fibers,” Opt.<br />
Express 18, 4547–4556 (2010).<br />
35. M. Liao, C. Chaudhari, G. Qin, X. Yan, C. Kito, T. Suzuki, Y.<br />
Ohishi, M. Matsumoto, and T. Misumi, “Fabrication and characterization<br />
of a chalcogeni<strong>de</strong>-tellurite composite microstructure<br />
fiber with high nonlinearity,” Opt. Express 17, 21608–21614<br />
(2009).<br />
36. K. Tai, A. Tomita, J. L. Jewell, and A. Hasegawa, “Generation of<br />
subpicosecond solitonlike optical pulses at 0:3 thz repetition<br />
rate by induced modulational instability,” Appl. Phys. Lett.<br />
236–238 (1986).<br />
37. P. V. Mamyshev, S. V. Chernikov, E. M. Dianov, and A. M.<br />
Prokhorov, “Generation of a high-repetition-rate train of practically<br />
noninteracting solitons by using the induced modulational<br />
instability and Raman self scattering effects,” Opt. Lett. 15,<br />
1365–1367 (1990).<br />
38. C. J. S. Matos, D. A. Chestnut, and J. R. Taylor, “Low-threshold<br />
self-induced modulational instability ring laser in highly nonlinear<br />
fiber yielding a continuous-wave 262 ghz soliton train,”<br />
Opt. Lett. 27, 915–917 (2002).<br />
39. Y. Gong, P. Shum, D. Tang, C. Lu, and X. Guo, “660 ghz solitons<br />
source based on modulation instability in short cavity,” Opt.<br />
Express 11, 2480–2485 (2003).
1528 J. Opt. Soc. Am. B / Vol. 28, No. 6 / June 2011 Zambo Abou’ou et al.<br />
7. M. J. Potasek and G. P. Agrawal, “Self-amplitu<strong>de</strong>-modulation of<br />
optical pulses in nonlinear dispersive fibers,” Phys. Rev. A 36,<br />
3862–3867 (1987).<br />
8. M. Nakazawa, K. Suzuki, and H. A. Haus, “The modulational<br />
instability laser. I. Experiment,” IEEE J. Quantum Electron.<br />
25, 2036–2044 (1989).<br />
9. P. Franco, F. Fontana, I. Cristiani, M. Midrio, and M. Romagnoli,<br />
“Self-induced modulational-instability laser,” Opt. Lett. 20,<br />
2009–2011 (1995).<br />
10. S. Coen and M. Haelterman, “Continuous-wave ultrahighrepetition-rate<br />
pulse-train generation through modulational instability<br />
in a passive fiber cavity,” Opt. Lett. 26, 39–41 (2001).<br />
11. T. Sylvestre, S. Coen, P. Emplit, and M. Haelterman, “Self-induced<br />
modulational instability laser revisited: normal dispersion and<br />
dark-pulse train generation,” Opt. Lett. 27, 482–484 (2002).<br />
12. A. Labruyere, S. Ambomo, C. Ngabireng, P. Tchofo Dinda,<br />
K. Nakkeeran, and K. Porsezian, “Suppression of si<strong>de</strong>band<br />
frequency shifts in the modulational instability spectra of wave<br />
propagation in optical fiber systems,” Opt. Lett. 32, 1287–<br />
1289 (2007).<br />
13. R. K. Jain and R. C. Lind, “Degenerate four-wave mixing in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. 73, 647–653 (1983).<br />
14. L. H. Acioli, A. S. L. Gomes, and J. R. R. Leite, “Measurement of<br />
high-or<strong>de</strong>r optical nonlinear susceptibilities in semiconductordoped<br />
glasses,” Appl. Phys. Lett. 53, 1788–1790 (1988).<br />
15. U. Langebein, F. Le<strong>de</strong>rer, T. Peschel, and H. E. Ponath, “Nonlinear<br />
gui<strong>de</strong>d waves in saturable nonlinear media,” Opt. Lett.<br />
10, 571–573 (1985).<br />
16. P. Roussignol, D. Ricard, J. Lukasik, and C. Flytzanis, “New<br />
results on optical phase conjugation in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. B 4, 5–13 (1987).<br />
17. C. N. Ironsi<strong>de</strong>, T. J. Cullen, B. S. Bhumbra, J. Bell, W. C. Banyai,<br />
N. Finlayson, C. T. Seaton, and G. I. Stegeman, “Nonlinearoptical<br />
effects in ion-exchanged semiconductor-doped glass<br />
wavegui<strong>de</strong>s,” J. Opt. Soc. Am. B 5, 492–495 (1988).<br />
18. J. L. Coutaz and M. Kull, “Saturation of nonlinear in<strong>de</strong>x of<br />
refraction in semiconductor-doped glass,” J. Opt. Soc. Am. B<br />
8, 95–98 (1991).<br />
19. X. H. Wang and G. K. Cambrell, “Simulation of strong nonlinear<br />
effects in optical wavegui<strong>de</strong>s,” J. Opt. Soc. Am. B 10,<br />
2048–2055 (1993).<br />
20. D. W. Hall, M. A. Newhouse, N. F. Borrelli, W. H. Dumbaugh, and<br />
D. L. Weidman, “Nonlinear optical susceptibilities of high-in<strong>de</strong>x<br />
glasses,” Appl. Phys. Lett. 54, 1293–1295 (1989).<br />
21. I. Kang, T. D. Krauss, F. W. Wise, B. G. Aitken, and N. F. Borrelli,<br />
“Femtosecond measurement of enhanced optical nonlinearities<br />
of sulphi<strong>de</strong> glasses and heavy-metal-doped oxi<strong>de</strong> glasses,” J.<br />
Opt. Soc. Am. B 12, 2053–2059 (1995).<br />
22. Y. F. Chen, K. Beckwitt, F. K. Wise, B. G. Aitken, J. S. Sanghera,<br />
and I. D. Aggarwal, “Measurement of fifth- and seventh-or<strong>de</strong>r<br />
nonlinearities of glasses,” J. Opt. Soc. Am. B 23, 347–352 (2006).<br />
23. M. N. Zambo Abou’ou, P. Tchofo Dinda, C. M. Ngabireng, B.<br />
Kibler, F. Smektala, and K. Porsezian, “Suppression of the<br />
frequency drift of modulational instability si<strong>de</strong>bands by means<br />
of a fiber system associated with a photon reservoir,” Opt. Lett.<br />
36, 256–258 (2011).<br />
24. P. Tchofo Dinda, and K. Porsezian, “Impact of fourth-or<strong>de</strong>r<br />
dispersion in the modulational instability spectra of wave<br />
propagation in glass fibers with saturable nonlinearity,” J.<br />
Opt. Soc. Am. B 27, 1143–1152 (2010).<br />
25. S. B. Cavalcanti, J. C. Cressoni, H. R. da Cruz, and A. S. Gouveia-<br />
Neto, “Modulation instability in the region of minimum groupvelocity<br />
dispersion of single-mo<strong>de</strong> optical fibers via an exten<strong>de</strong>d<br />
nonlinear Schrodinger equation,” Phys. Rev. A 43, 6162–6165<br />
(1991).<br />
26. J. H. Chou and R. Wu, “A generalization of the frobenius method<br />
for ordinary differential equations with regular singular points,”<br />
J. Math. Stat. 1, 3–7 (2005).<br />
27. A. Ferrando, E. Silvestre, J. J. Miret, and P. Andres, “Nearly zero<br />
ultraflattened dispersion in photonic crystal fibers,” Opt. Lett.<br />
25, 790–792 (2000).<br />
28. T. A. Birks, W. J. Wadsworth, and P. St. J. Russell, “Supercontinuum<br />
generation in tapered fibers,” Opt. Lett. 25, 1415–1417<br />
(2000).<br />
29. S. G. Leon-Saval, T. A. Birks, W. J. Wadsworth, and P. St. J.<br />
Russell, “Supercontinuum generation in submicron fibre wavegui<strong>de</strong>s,”<br />
Opt. Express 12, 2864–2869 (2004).<br />
30. V. V. Ravi Kanth Kumar, A. George, and P. Russel,<br />
“Tellurite photonic crystal fiber,” Opt. Express 11, 2641–2645<br />
(2003).<br />
31. L. Brilland, F. Smektala, G. Renversez, T. Chartier, J. Troles, T.<br />
N. Nguyen, N. Traynor, and A. Monteville, “Fabrication of<br />
complex structures of holey fibers in chalcogeni<strong>de</strong> glass,”<br />
Opt. Express 14, 1280–1285 (2006).<br />
32. C. Chaudhari, T. Suzuki, and Y. Ohishi, “Design of zero<br />
chromatic dispersion chalcogeni<strong>de</strong> As 2S 3 glass nanofibers,” J.<br />
Lightwave Technol. 27, 2095–2099 (2009).<br />
33. A. W. Sny<strong>de</strong>r and J. D. Love, Optical Wavegui<strong>de</strong> Theory<br />
(Chapman and Hall, 1983).<br />
34. M. El-Amraoui, J. Fatome, J. C. Jules, B. Kibler, G. Gadret,<br />
C. Fortier, F. Smektala, I. Skripatchev, C. F. Polacchini, Y.<br />
Messad<strong>de</strong>q, J. Troles, L. Brilland, M. Szpulak, and G. Renversez,<br />
“Strong infrared spectral broa<strong>de</strong>ning in low-loss As-S chalcogeni<strong>de</strong><br />
suspen<strong>de</strong>d core microstructured optical fibers,” Opt.<br />
Express 18, 4547–4556 (2010).<br />
35. M. Liao, C. Chaudhari, G. Qin, X. Yan, C. Kito, T. Suzuki, Y.<br />
Ohishi, M. Matsumoto, and T. Misumi, “Fabrication and characterization<br />
of a chalcogeni<strong>de</strong>-tellurite composite microstructure<br />
fiber with high nonlinearity,” Opt. Express 17, 21608–21614<br />
(2009).<br />
36. K. Tai, A. Tomita, J. L. Jewell, and A. Hasegawa, “Generation of<br />
subpicosecond solitonlike optical pulses at 0:3 thz repetition<br />
rate by induced modulational instability,” Appl. Phys. Lett.<br />
236–238 (1986).<br />
37. P. V. Mamyshev, S. V. Chernikov, E. M. Dianov, and A. M.<br />
Prokhorov, “Generation of a high-repetition-rate train of practically<br />
noninteracting solitons by using the induced modulational<br />
instability and Raman self scattering effects,” Opt. Lett. 15,<br />
1365–1367 (1990).<br />
38. C. J. S. Matos, D. A. Chestnut, and J. R. Taylor, “Low-threshold<br />
self-induced modulational instability ring laser in highly nonlinear<br />
fiber yielding a continuous-wave 262 ghz soliton train,”<br />
Opt. Lett. 27, 915–917 (2002).<br />
39. Y. Gong, P. Shum, D. Tang, C. Lu, and X. Guo, “660 ghz solitons<br />
source based on modulation instability in short cavity,” Opt.<br />
Express 11, 2480–2485 (2003).
1528 J. Opt. Soc. Am. B / Vol. 28, No. 6 / June 2011 Zambo Abou’ou et al.<br />
7. M. J. Potasek and G. P. Agrawal, “Self-amplitu<strong>de</strong>-modulation of<br />
optical pulses in nonlinear dispersive fibers,” Phys. Rev. A 36,<br />
3862–3867 (1987).<br />
8. M. Nakazawa, K. Suzuki, and H. A. Haus, “The modulational<br />
instability laser. I. Experiment,” IEEE J. Quantum Electron.<br />
25, 2036–2044 (1989).<br />
9. P. Franco, F. Fontana, I. Cristiani, M. Midrio, and M. Romagnoli,<br />
“Self-induced modulational-instability laser,” Opt. Lett. 20,<br />
2009–2011 (1995).<br />
10. S. Coen and M. Haelterman, “Continuous-wave ultrahighrepetition-rate<br />
pulse-train generation through modulational instability<br />
in a passive fiber cavity,” Opt. Lett. 26, 39–41 (2001).<br />
11. T. Sylvestre, S. Coen, P. Emplit, and M. Haelterman, “Self-induced<br />
modulational instability laser revisited: normal dispersion and<br />
dark-pulse train generation,” Opt. Lett. 27, 482–484 (2002).<br />
12. A. Labruyere, S. Ambomo, C. Ngabireng, P. Tchofo Dinda,<br />
K. Nakkeeran, and K. Porsezian, “Suppression of si<strong>de</strong>band<br />
frequency shifts in the modulational instability spectra of wave<br />
propagation in optical fiber systems,” Opt. Lett. 32, 1287–<br />
1289 (2007).<br />
13. R. K. Jain and R. C. Lind, “Degenerate four-wave mixing in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. 73, 647–653 (1983).<br />
14. L. H. Acioli, A. S. L. Gomes, and J. R. R. Leite, “Measurement of<br />
high-or<strong>de</strong>r optical nonlinear susceptibilities in semiconductordoped<br />
glasses,” Appl. Phys. Lett. 53, 1788–1790 (1988).<br />
15. U. Langebein, F. Le<strong>de</strong>rer, T. Peschel, and H. E. Ponath, “Nonlinear<br />
gui<strong>de</strong>d waves in saturable nonlinear media,” Opt. Lett.<br />
10, 571–573 (1985).<br />
16. P. Roussignol, D. Ricard, J. Lukasik, and C. Flytzanis, “New<br />
results on optical phase conjugation in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. B 4, 5–13 (1987).<br />
17. C. N. Ironsi<strong>de</strong>, T. J. Cullen, B. S. Bhumbra, J. Bell, W. C. Banyai,<br />
N. Finlayson, C. T. Seaton, and G. I. Stegeman, “Nonlinearoptical<br />
effects in ion-exchanged semiconductor-doped glass<br />
wavegui<strong>de</strong>s,” J. Opt. Soc. Am. B 5, 492–495 (1988).<br />
18. J. L. Coutaz and M. Kull, “Saturation of nonlinear in<strong>de</strong>x of<br />
refraction in semiconductor-doped glass,” J. Opt. Soc. Am. B<br />
8, 95–98 (1991).<br />
19. X. H. Wang and G. K. Cambrell, “Simulation of strong nonlinear<br />
effects in optical wavegui<strong>de</strong>s,” J. Opt. Soc. Am. B 10,<br />
2048–2055 (1993).<br />
20. D. W. Hall, M. A. Newhouse, N. F. Borrelli, W. H. Dumbaugh, and<br />
D. L. Weidman, “Nonlinear optical susceptibilities of high-in<strong>de</strong>x<br />
glasses,” Appl. Phys. Lett. 54, 1293–1295 (1989).<br />
21. I. Kang, T. D. Krauss, F. W. Wise, B. G. Aitken, and N. F. Borrelli,<br />
“Femtosecond measurement of enhanced optical nonlinearities<br />
of sulphi<strong>de</strong> glasses and heavy-metal-doped oxi<strong>de</strong> glasses,” J.<br />
Opt. Soc. Am. B 12, 2053–2059 (1995).<br />
22. Y. F. Chen, K. Beckwitt, F. K. Wise, B. G. Aitken, J. S. Sanghera,<br />
and I. D. Aggarwal, “Measurement of fifth- and seventh-or<strong>de</strong>r<br />
nonlinearities of glasses,” J. Opt. Soc. Am. B 23, 347–352 (2006).<br />
23. M. N. Zambo Abou’ou, P. Tchofo Dinda, C. M. Ngabireng, B.<br />
Kibler, F. Smektala, and K. Porsezian, “Suppression of the<br />
frequency drift of modulational instability si<strong>de</strong>bands by means<br />
of a fiber system associated with a photon reservoir,” Opt. Lett.<br />
36, 256–258 (2011).<br />
24. P. Tchofo Dinda, and K. Porsezian, “Impact of fourth-or<strong>de</strong>r<br />
dispersion in the modulational instability spectra of wave<br />
propagation in glass fibers with saturable nonlinearity,” J.<br />
Opt. Soc. Am. B 27, 1143–1152 (2010).<br />
25. S. B. Cavalcanti, J. C. Cressoni, H. R. da Cruz, and A. S. Gouveia-<br />
Neto, “Modulation instability in the region of minimum groupvelocity<br />
dispersion of single-mo<strong>de</strong> optical fibers via an exten<strong>de</strong>d<br />
nonlinear Schrodinger equation,” Phys. Rev. A 43, 6162–6165<br />
(1991).<br />
26. J. H. Chou and R. Wu, “A generalization of the frobenius method<br />
for ordinary differential equations with regular singular points,”<br />
J. Math. Stat. 1, 3–7 (2005).<br />
27. A. Ferrando, E. Silvestre, J. J. Miret, and P. Andres, “Nearly zero<br />
ultraflattened dispersion in photonic crystal fibers,” Opt. Lett.<br />
25, 790–792 (2000).<br />
28. T. A. Birks, W. J. Wadsworth, and P. St. J. Russell, “Supercontinuum<br />
generation in tapered fibers,” Opt. Lett. 25, 1415–1417<br />
(2000).<br />
29. S. G. Leon-Saval, T. A. Birks, W. J. Wadsworth, and P. St. J.<br />
Russell, “Supercontinuum generation in submicron fibre wavegui<strong>de</strong>s,”<br />
Opt. Express 12, 2864–2869 (2004).<br />
30. V. V. Ravi Kanth Kumar, A. George, and P. Russel,<br />
“Tellurite photonic crystal fiber,” Opt. Express 11, 2641–2645<br />
(2003).<br />
31. L. Brilland, F. Smektala, G. Renversez, T. Chartier, J. Troles, T.<br />
N. Nguyen, N. Traynor, and A. Monteville, “Fabrication of<br />
complex structures of holey fibers in chalcogeni<strong>de</strong> glass,”<br />
Opt. Express 14, 1280–1285 (2006).<br />
32. C. Chaudhari, T. Suzuki, and Y. Ohishi, “Design of zero<br />
chromatic dispersion chalcogeni<strong>de</strong> As 2S 3 glass nanofibers,” J.<br />
Lightwave Technol. 27, 2095–2099 (2009).<br />
33. A. W. Sny<strong>de</strong>r and J. D. Love, Optical Wavegui<strong>de</strong> Theory<br />
(Chapman and Hall, 1983).<br />
34. M. El-Amraoui, J. Fatome, J. C. Jules, B. Kibler, G. Gadret,<br />
C. Fortier, F. Smektala, I. Skripatchev, C. F. Polacchini, Y.<br />
Messad<strong>de</strong>q, J. Troles, L. Brilland, M. Szpulak, and G. Renversez,<br />
“Strong infrared spectral broa<strong>de</strong>ning in low-loss As-S chalcogeni<strong>de</strong><br />
suspen<strong>de</strong>d core microstructured optical fibers,” Opt.<br />
Express 18, 4547–4556 (2010).<br />
35. M. Liao, C. Chaudhari, G. Qin, X. Yan, C. Kito, T. Suzuki, Y.<br />
Ohishi, M. Matsumoto, and T. Misumi, “Fabrication and characterization<br />
of a chalcogeni<strong>de</strong>-tellurite composite microstructure<br />
fiber with high nonlinearity,” Opt. Express 17, 21608–21614<br />
(2009).<br />
36. K. Tai, A. Tomita, J. L. Jewell, and A. Hasegawa, “Generation of<br />
subpicosecond solitonlike optical pulses at 0:3 thz repetition<br />
rate by induced modulational instability,” Appl. Phys. Lett.<br />
236–238 (1986).<br />
37. P. V. Mamyshev, S. V. Chernikov, E. M. Dianov, and A. M.<br />
Prokhorov, “Generation of a high-repetition-rate train of practically<br />
noninteracting solitons by using the induced modulational<br />
instability and Raman self scattering effects,” Opt. Lett. 15,<br />
1365–1367 (1990).<br />
38. C. J. S. Matos, D. A. Chestnut, and J. R. Taylor, “Low-threshold<br />
self-induced modulational instability ring laser in highly nonlinear<br />
fiber yielding a continuous-wave 262 ghz soliton train,”<br />
Opt. Lett. 27, 915–917 (2002).<br />
39. Y. Gong, P. Shum, D. Tang, C. Lu, and X. Guo, “660 ghz solitons<br />
source based on modulation instability in short cavity,” Opt.<br />
Express 11, 2480–2485 (2003).
1528 J. Opt. Soc. Am. B / Vol. 28, No. 6 / June 2011 Zambo Abou’ou et al.<br />
7. M. J. Potasek and G. P. Agrawal, “Self-amplitu<strong>de</strong>-modulation of<br />
optical pulses in nonlinear dispersive fibers,” Phys. Rev. A 36,<br />
3862–3867 (1987).<br />
8. M. Nakazawa, K. Suzuki, and H. A. Haus, “The modulational<br />
instability laser. I. Experiment,” IEEE J. Quantum Electron.<br />
25, 2036–2044 (1989).<br />
9. P. Franco, F. Fontana, I. Cristiani, M. Midrio, and M. Romagnoli,<br />
“Self-induced modulational-instability laser,” Opt. Lett. 20,<br />
2009–2011 (1995).<br />
10. S. Coen and M. Haelterman, “Continuous-wave ultrahighrepetition-rate<br />
pulse-train generation through modulational instability<br />
in a passive fiber cavity,” Opt. Lett. 26, 39–41 (2001).<br />
11. T. Sylvestre, S. Coen, P. Emplit, and M. Haelterman, “Self-induced<br />
modulational instability laser revisited: normal dispersion and<br />
dark-pulse train generation,” Opt. Lett. 27, 482–484 (2002).<br />
12. A. Labruyere, S. Ambomo, C. Ngabireng, P. Tchofo Dinda,<br />
K. Nakkeeran, and K. Porsezian, “Suppression of si<strong>de</strong>band<br />
frequency shifts in the modulational instability spectra of wave<br />
propagation in optical fiber systems,” Opt. Lett. 32, 1287–<br />
1289 (2007).<br />
13. R. K. Jain and R. C. Lind, “Degenerate four-wave mixing in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. 73, 647–653 (1983).<br />
14. L. H. Acioli, A. S. L. Gomes, and J. R. R. Leite, “Measurement of<br />
high-or<strong>de</strong>r optical nonlinear susceptibilities in semiconductordoped<br />
glasses,” Appl. Phys. Lett. 53, 1788–1790 (1988).<br />
15. U. Langebein, F. Le<strong>de</strong>rer, T. Peschel, and H. E. Ponath, “Nonlinear<br />
gui<strong>de</strong>d waves in saturable nonlinear media,” Opt. Lett.<br />
10, 571–573 (1985).<br />
16. P. Roussignol, D. Ricard, J. Lukasik, and C. Flytzanis, “New<br />
results on optical phase conjugation in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. B 4, 5–13 (1987).<br />
17. C. N. Ironsi<strong>de</strong>, T. J. Cullen, B. S. Bhumbra, J. Bell, W. C. Banyai,<br />
N. Finlayson, C. T. Seaton, and G. I. Stegeman, “Nonlinearoptical<br />
effects in ion-exchanged semiconductor-doped glass<br />
wavegui<strong>de</strong>s,” J. Opt. Soc. Am. B 5, 492–495 (1988).<br />
18. J. L. Coutaz and M. Kull, “Saturation of nonlinear in<strong>de</strong>x of<br />
refraction in semiconductor-doped glass,” J. Opt. Soc. Am. B<br />
8, 95–98 (1991).<br />
19. X. H. Wang and G. K. Cambrell, “Simulation of strong nonlinear<br />
effects in optical wavegui<strong>de</strong>s,” J. Opt. Soc. Am. B 10,<br />
2048–2055 (1993).<br />
20. D. W. Hall, M. A. Newhouse, N. F. Borrelli, W. H. Dumbaugh, and<br />
D. L. Weidman, “Nonlinear optical susceptibilities of high-in<strong>de</strong>x<br />
glasses,” Appl. Phys. Lett. 54, 1293–1295 (1989).<br />
21. I. Kang, T. D. Krauss, F. W. Wise, B. G. Aitken, and N. F. Borrelli,<br />
“Femtosecond measurement of enhanced optical nonlinearities<br />
of sulphi<strong>de</strong> glasses and heavy-metal-doped oxi<strong>de</strong> glasses,” J.<br />
Opt. Soc. Am. B 12, 2053–2059 (1995).<br />
22. Y. F. Chen, K. Beckwitt, F. K. Wise, B. G. Aitken, J. S. Sanghera,<br />
and I. D. Aggarwal, “Measurement of fifth- and seventh-or<strong>de</strong>r<br />
nonlinearities of glasses,” J. Opt. Soc. Am. B 23, 347–352 (2006).<br />
23. M. N. Zambo Abou’ou, P. Tchofo Dinda, C. M. Ngabireng, B.<br />
Kibler, F. Smektala, and K. Porsezian, “Suppression of the<br />
frequency drift of modulational instability si<strong>de</strong>bands by means<br />
of a fiber system associated with a photon reservoir,” Opt. Lett.<br />
36, 256–258 (2011).<br />
24. P. Tchofo Dinda, and K. Porsezian, “Impact of fourth-or<strong>de</strong>r<br />
dispersion in the modulational instability spectra of wave<br />
propagation in glass fibers with saturable nonlinearity,” J.<br />
Opt. Soc. Am. B 27, 1143–1152 (2010).<br />
25. S. B. Cavalcanti, J. C. Cressoni, H. R. da Cruz, and A. S. Gouveia-<br />
Neto, “Modulation instability in the region of minimum groupvelocity<br />
dispersion of single-mo<strong>de</strong> optical fibers via an exten<strong>de</strong>d<br />
nonlinear Schrodinger equation,” Phys. Rev. A 43, 6162–6165<br />
(1991).<br />
26. J. H. Chou and R. Wu, “A generalization of the frobenius method<br />
for ordinary differential equations with regular singular points,”<br />
J. Math. Stat. 1, 3–7 (2005).<br />
27. A. Ferrando, E. Silvestre, J. J. Miret, and P. Andres, “Nearly zero<br />
ultraflattened dispersion in photonic crystal fibers,” Opt. Lett.<br />
25, 790–792 (2000).<br />
28. T. A. Birks, W. J. Wadsworth, and P. St. J. Russell, “Supercontinuum<br />
generation in tapered fibers,” Opt. Lett. 25, 1415–1417<br />
(2000).<br />
29. S. G. Leon-Saval, T. A. Birks, W. J. Wadsworth, and P. St. J.<br />
Russell, “Supercontinuum generation in submicron fibre wavegui<strong>de</strong>s,”<br />
Opt. Express 12, 2864–2869 (2004).<br />
30. V. V. Ravi Kanth Kumar, A. George, and P. Russel,<br />
“Tellurite photonic crystal fiber,” Opt. Express 11, 2641–2645<br />
(2003).<br />
31. L. Brilland, F. Smektala, G. Renversez, T. Chartier, J. Troles, T.<br />
N. Nguyen, N. Traynor, and A. Monteville, “Fabrication of<br />
complex structures of holey fibers in chalcogeni<strong>de</strong> glass,”<br />
Opt. Express 14, 1280–1285 (2006).<br />
32. C. Chaudhari, T. Suzuki, and Y. Ohishi, “Design of zero<br />
chromatic dispersion chalcogeni<strong>de</strong> As 2S 3 glass nanofibers,” J.<br />
Lightwave Technol. 27, 2095–2099 (2009).<br />
33. A. W. Sny<strong>de</strong>r and J. D. Love, Optical Wavegui<strong>de</strong> Theory<br />
(Chapman and Hall, 1983).<br />
34. M. El-Amraoui, J. Fatome, J. C. Jules, B. Kibler, G. Gadret,<br />
C. Fortier, F. Smektala, I. Skripatchev, C. F. Polacchini, Y.<br />
Messad<strong>de</strong>q, J. Troles, L. Brilland, M. Szpulak, and G. Renversez,<br />
“Strong infrared spectral broa<strong>de</strong>ning in low-loss As-S chalcogeni<strong>de</strong><br />
suspen<strong>de</strong>d core microstructured optical fibers,” Opt.<br />
Express 18, 4547–4556 (2010).<br />
35. M. Liao, C. Chaudhari, G. Qin, X. Yan, C. Kito, T. Suzuki, Y.<br />
Ohishi, M. Matsumoto, and T. Misumi, “Fabrication and characterization<br />
of a chalcogeni<strong>de</strong>-tellurite composite microstructure<br />
fiber with high nonlinearity,” Opt. Express 17, 21608–21614<br />
(2009).<br />
36. K. Tai, A. Tomita, J. L. Jewell, and A. Hasegawa, “Generation of<br />
subpicosecond solitonlike optical pulses at 0:3 thz repetition<br />
rate by induced modulational instability,” Appl. Phys. Lett.<br />
236–238 (1986).<br />
37. P. V. Mamyshev, S. V. Chernikov, E. M. Dianov, and A. M.<br />
Prokhorov, “Generation of a high-repetition-rate train of practically<br />
noninteracting solitons by using the induced modulational<br />
instability and Raman self scattering effects,” Opt. Lett. 15,<br />
1365–1367 (1990).<br />
38. C. J. S. Matos, D. A. Chestnut, and J. R. Taylor, “Low-threshold<br />
self-induced modulational instability ring laser in highly nonlinear<br />
fiber yielding a continuous-wave 262 ghz soliton train,”<br />
Opt. Lett. 27, 915–917 (2002).<br />
39. Y. Gong, P. Shum, D. Tang, C. Lu, and X. Guo, “660 ghz solitons<br />
source based on modulation instability in short cavity,” Opt.<br />
Express 11, 2480–2485 (2003).
1528 J. Opt. Soc. Am. B / Vol. 28, No. 6 / June 2011 Zambo Abou’ou et al.<br />
7. M. J. Potasek and G. P. Agrawal, “Self-amplitu<strong>de</strong>-modulation of<br />
optical pulses in nonlinear dispersive fibers,” Phys. Rev. A 36,<br />
3862–3867 (1987).<br />
8. M. Nakazawa, K. Suzuki, and H. A. Haus, “The modulational<br />
instability laser. I. Experiment,” IEEE J. Quantum Electron.<br />
25, 2036–2044 (1989).<br />
9. P. Franco, F. Fontana, I. Cristiani, M. Midrio, and M. Romagnoli,<br />
“Self-induced modulational-instability laser,” Opt. Lett. 20,<br />
2009–2011 (1995).<br />
10. S. Coen and M. Haelterman, “Continuous-wave ultrahighrepetition-rate<br />
pulse-train generation through modulational instability<br />
in a passive fiber cavity,” Opt. Lett. 26, 39–41 (2001).<br />
11. T. Sylvestre, S. Coen, P. Emplit, and M. Haelterman, “Self-induced<br />
modulational instability laser revisited: normal dispersion and<br />
dark-pulse train generation,” Opt. Lett. 27, 482–484 (2002).<br />
12. A. Labruyere, S. Ambomo, C. Ngabireng, P. Tchofo Dinda,<br />
K. Nakkeeran, and K. Porsezian, “Suppression of si<strong>de</strong>band<br />
frequency shifts in the modulational instability spectra of wave<br />
propagation in optical fiber systems,” Opt. Lett. 32, 1287–<br />
1289 (2007).<br />
13. R. K. Jain and R. C. Lind, “Degenerate four-wave mixing in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. 73, 647–653 (1983).<br />
14. L. H. Acioli, A. S. L. Gomes, and J. R. R. Leite, “Measurement of<br />
high-or<strong>de</strong>r optical nonlinear susceptibilities in semiconductordoped<br />
glasses,” Appl. Phys. Lett. 53, 1788–1790 (1988).<br />
15. U. Langebein, F. Le<strong>de</strong>rer, T. Peschel, and H. E. Ponath, “Nonlinear<br />
gui<strong>de</strong>d waves in saturable nonlinear media,” Opt. Lett.<br />
10, 571–573 (1985).<br />
16. P. Roussignol, D. Ricard, J. Lukasik, and C. Flytzanis, “New<br />
results on optical phase conjugation in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. B 4, 5–13 (1987).<br />
17. C. N. Ironsi<strong>de</strong>, T. J. Cullen, B. S. Bhumbra, J. Bell, W. C. Banyai,<br />
N. Finlayson, C. T. Seaton, and G. I. Stegeman, “Nonlinearoptical<br />
effects in ion-exchanged semiconductor-doped glass<br />
wavegui<strong>de</strong>s,” J. Opt. Soc. Am. B 5, 492–495 (1988).<br />
18. J. L. Coutaz and M. Kull, “Saturation of nonlinear in<strong>de</strong>x of<br />
refraction in semiconductor-doped glass,” J. Opt. Soc. Am. B<br />
8, 95–98 (1991).<br />
19. X. H. Wang and G. K. Cambrell, “Simulation of strong nonlinear<br />
effects in optical wavegui<strong>de</strong>s,” J. Opt. Soc. Am. B 10,<br />
2048–2055 (1993).<br />
20. D. W. Hall, M. A. Newhouse, N. F. Borrelli, W. H. Dumbaugh, and<br />
D. L. Weidman, “Nonlinear optical susceptibilities of high-in<strong>de</strong>x<br />
glasses,” Appl. Phys. Lett. 54, 1293–1295 (1989).<br />
21. I. Kang, T. D. Krauss, F. W. Wise, B. G. Aitken, and N. F. Borrelli,<br />
“Femtosecond measurement of enhanced optical nonlinearities<br />
of sulphi<strong>de</strong> glasses and heavy-metal-doped oxi<strong>de</strong> glasses,” J.<br />
Opt. Soc. Am. B 12, 2053–2059 (1995).<br />
22. Y. F. Chen, K. Beckwitt, F. K. Wise, B. G. Aitken, J. S. Sanghera,<br />
and I. D. Aggarwal, “Measurement of fifth- and seventh-or<strong>de</strong>r<br />
nonlinearities of glasses,” J. Opt. Soc. Am. B 23, 347–352 (2006).<br />
23. M. N. Zambo Abou’ou, P. Tchofo Dinda, C. M. Ngabireng, B.<br />
Kibler, F. Smektala, and K. Porsezian, “Suppression of the<br />
frequency drift of modulational instability si<strong>de</strong>bands by means<br />
of a fiber system associated with a photon reservoir,” Opt. Lett.<br />
36, 256–258 (2011).<br />
24. P. Tchofo Dinda, and K. Porsezian, “Impact of fourth-or<strong>de</strong>r<br />
dispersion in the modulational instability spectra of wave<br />
propagation in glass fibers with saturable nonlinearity,” J.<br />
Opt. Soc. Am. B 27, 1143–1152 (2010).<br />
25. S. B. Cavalcanti, J. C. Cressoni, H. R. da Cruz, and A. S. Gouveia-<br />
Neto, “Modulation instability in the region of minimum groupvelocity<br />
dispersion of single-mo<strong>de</strong> optical fibers via an exten<strong>de</strong>d<br />
nonlinear Schrodinger equation,” Phys. Rev. A 43, 6162–6165<br />
(1991).<br />
26. J. H. Chou and R. Wu, “A generalization of the frobenius method<br />
for ordinary differential equations with regular singular points,”<br />
J. Math. Stat. 1, 3–7 (2005).<br />
27. A. Ferrando, E. Silvestre, J. J. Miret, and P. Andres, “Nearly zero<br />
ultraflattened dispersion in photonic crystal fibers,” Opt. Lett.<br />
25, 790–792 (2000).<br />
28. T. A. Birks, W. J. Wadsworth, and P. St. J. Russell, “Supercontinuum<br />
generation in tapered fibers,” Opt. Lett. 25, 1415–1417<br />
(2000).<br />
29. S. G. Leon-Saval, T. A. Birks, W. J. Wadsworth, and P. St. J.<br />
Russell, “Supercontinuum generation in submicron fibre wavegui<strong>de</strong>s,”<br />
Opt. Express 12, 2864–2869 (2004).<br />
30. V. V. Ravi Kanth Kumar, A. George, and P. Russel,<br />
“Tellurite photonic crystal fiber,” Opt. Express 11, 2641–2645<br />
(2003).<br />
31. L. Brilland, F. Smektala, G. Renversez, T. Chartier, J. Troles, T.<br />
N. Nguyen, N. Traynor, and A. Monteville, “Fabrication of<br />
complex structures of holey fibers in chalcogeni<strong>de</strong> glass,”<br />
Opt. Express 14, 1280–1285 (2006).<br />
32. C. Chaudhari, T. Suzuki, and Y. Ohishi, “Design of zero<br />
chromatic dispersion chalcogeni<strong>de</strong> As 2S 3 glass nanofibers,” J.<br />
Lightwave Technol. 27, 2095–2099 (2009).<br />
33. A. W. Sny<strong>de</strong>r and J. D. Love, Optical Wavegui<strong>de</strong> Theory<br />
(Chapman and Hall, 1983).<br />
34. M. El-Amraoui, J. Fatome, J. C. Jules, B. Kibler, G. Gadret,<br />
C. Fortier, F. Smektala, I. Skripatchev, C. F. Polacchini, Y.<br />
Messad<strong>de</strong>q, J. Troles, L. Brilland, M. Szpulak, and G. Renversez,<br />
“Strong infrared spectral broa<strong>de</strong>ning in low-loss As-S chalcogeni<strong>de</strong><br />
suspen<strong>de</strong>d core microstructured optical fibers,” Opt.<br />
Express 18, 4547–4556 (2010).<br />
35. M. Liao, C. Chaudhari, G. Qin, X. Yan, C. Kito, T. Suzuki, Y.<br />
Ohishi, M. Matsumoto, and T. Misumi, “Fabrication and characterization<br />
of a chalcogeni<strong>de</strong>-tellurite composite microstructure<br />
fiber with high nonlinearity,” Opt. Express 17, 21608–21614<br />
(2009).<br />
36. K. Tai, A. Tomita, J. L. Jewell, and A. Hasegawa, “Generation of<br />
subpicosecond solitonlike optical pulses at 0:3 thz repetition<br />
rate by induced modulational instability,” Appl. Phys. Lett.<br />
236–238 (1986).<br />
37. P. V. Mamyshev, S. V. Chernikov, E. M. Dianov, and A. M.<br />
Prokhorov, “Generation of a high-repetition-rate train of practically<br />
noninteracting solitons by using the induced modulational<br />
instability and Raman self scattering effects,” Opt. Lett. 15,<br />
1365–1367 (1990).<br />
38. C. J. S. Matos, D. A. Chestnut, and J. R. Taylor, “Low-threshold<br />
self-induced modulational instability ring laser in highly nonlinear<br />
fiber yielding a continuous-wave 262 ghz soliton train,”<br />
Opt. Lett. 27, 915–917 (2002).<br />
39. Y. Gong, P. Shum, D. Tang, C. Lu, and X. Guo, “660 ghz solitons<br />
source based on modulation instability in short cavity,” Opt.<br />
Express 11, 2480–2485 (2003).
1528 J. Opt. Soc. Am. B / Vol. 28, No. 6 / June 2011 Zambo Abou’ou et al.<br />
7. M. J. Potasek and G. P. Agrawal, “Self-amplitu<strong>de</strong>-modulation of<br />
optical pulses in nonlinear dispersive fibers,” Phys. Rev. A 36,<br />
3862–3867 (1987).<br />
8. M. Nakazawa, K. Suzuki, and H. A. Haus, “The modulational<br />
instability laser. I. Experiment,” IEEE J. Quantum Electron.<br />
25, 2036–2044 (1989).<br />
9. P. Franco, F. Fontana, I. Cristiani, M. Midrio, and M. Romagnoli,<br />
“Self-induced modulational-instability laser,” Opt. Lett. 20,<br />
2009–2011 (1995).<br />
10. S. Coen and M. Haelterman, “Continuous-wave ultrahighrepetition-rate<br />
pulse-train generation through modulational instability<br />
in a passive fiber cavity,” Opt. Lett. 26, 39–41 (2001).<br />
11. T. Sylvestre, S. Coen, P. Emplit, and M. Haelterman, “Self-induced<br />
modulational instability laser revisited: normal dispersion and<br />
dark-pulse train generation,” Opt. Lett. 27, 482–484 (2002).<br />
12. A. Labruyere, S. Ambomo, C. Ngabireng, P. Tchofo Dinda,<br />
K. Nakkeeran, and K. Porsezian, “Suppression of si<strong>de</strong>band<br />
frequency shifts in the modulational instability spectra of wave<br />
propagation in optical fiber systems,” Opt. Lett. 32, 1287–<br />
1289 (2007).<br />
13. R. K. Jain and R. C. Lind, “Degenerate four-wave mixing in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. 73, 647–653 (1983).<br />
14. L. H. Acioli, A. S. L. Gomes, and J. R. R. Leite, “Measurement of<br />
high-or<strong>de</strong>r optical nonlinear susceptibilities in semiconductordoped<br />
glasses,” Appl. Phys. Lett. 53, 1788–1790 (1988).<br />
15. U. Langebein, F. Le<strong>de</strong>rer, T. Peschel, and H. E. Ponath, “Nonlinear<br />
gui<strong>de</strong>d waves in saturable nonlinear media,” Opt. Lett.<br />
10, 571–573 (1985).<br />
16. P. Roussignol, D. Ricard, J. Lukasik, and C. Flytzanis, “New<br />
results on optical phase conjugation in semiconductor-doped<br />
glasses,” J. Opt. Soc. Am. B 4, 5–13 (1987).<br />
17. C. N. Ironsi<strong>de</strong>, T. J. Cullen, B. S. Bhumbra, J. Bell, W. C. Banyai,<br />
N. Finlayson, C. T. Seaton, and G. I. Stegeman, “Nonlinearoptical<br />
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