24.07.2013 Views

Experiments to Control Atom Number and Phase-Space Density in ...

Experiments to Control Atom Number and Phase-Space Density in ...

Experiments to Control Atom Number and Phase-Space Density in ...

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

The right h<strong>and</strong> side of equation 7.12 consists of a vec<strong>to</strong>r (I−ˆz ′ ˆz ′ )·ˆσ− <strong>and</strong> a scalar ˆσ ∗ −·ˆǫ.<br />

The first solution is hence<br />

ˆǫ1 = γ(I− ˆz ′ ˆz ′ )·ˆσ− = ˆx ′<br />

ξ1 =<br />

Here γ is the normalization constant.<br />

<br />

1<br />

ˆσ<br />

γ<br />

∗ − ·ˆǫ = 1<br />

2<br />

(7.13)<br />

(7.14)<br />

The second solution is easily found as it has <strong>to</strong> be perpendicular <strong>to</strong> the propaga-<br />

tion direction (ˆz ′ · ˆǫ2 = 0) <strong>and</strong> the already known solution (ˆǫ ∗ 2 · ˆǫ1 = 0). The solutions<br />

are thus<br />

ˆǫ2 = ˆy ′<br />

(7.15)<br />

ξ2 = 0. (7.16)<br />

Every polarization can be decomposed <strong>in</strong><strong>to</strong> the two eigenpolarizations, one <strong>in</strong>ter-<br />

act<strong>in</strong>g with the a<strong>to</strong>ms (ˆǫ1), <strong>and</strong> one not (ˆǫ2).<br />

In general the <strong>in</strong>cident field is given by<br />

1<br />

E<strong>in</strong>c = E0 ˆǫ ′ <strong>in</strong>c = E0√<br />

(ˆǫ<br />

2 ′ 1 ∓iˆǫ ′ 2). (7.17)<br />

Exp<strong>and</strong><strong>in</strong>g this field <strong>in</strong> terms of the eigenpolarization leads <strong>to</strong><br />

E<strong>in</strong>c = E0 (ˆǫ<strong>in</strong>c ·ˆǫ ∗ 1)ˆǫ1 +E0 (ˆǫ<strong>in</strong>c ·ˆǫ ∗ 2)ˆǫ2. (7.18)<br />

The field <strong>in</strong> the object plane of the imag<strong>in</strong>g system can then be derived by apply<strong>in</strong>g the<br />

same ansatz <strong>to</strong> each term:<br />

Eobj = E0(ˆǫ ′ <strong>in</strong>c ·ˆǫ ∗ 1)exp<br />

<br />

−nξ1σ0<br />

2(1+δ 2 <br />

(1+iδ) ˆǫ1 +E0(ˆǫ<br />

)<br />

′ <strong>in</strong>c ·ˆǫ ∗ 2)ˆǫ2<br />

(7.19)<br />

For the <strong>in</strong>com<strong>in</strong>g polarization <strong>in</strong> the experimental setup, ˆǫ ′ <strong>in</strong>c = 1/ √ 2(ˆx ′ ∓iˆy ′ ), the field<br />

<strong>in</strong> the object plane simplifies <strong>to</strong><br />

Eobj = E0<br />

√2 exp<br />

<br />

−nξ1σ0<br />

2(1+δ 2 <br />

(1+iδ) ˆǫ1 ∓<br />

)<br />

iE0<br />

√2ˆǫ2, (7.20)<br />

144

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!