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 ...
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Imag<strong>in</strong>g<br />
ber<br />
Imag<strong>in</strong>g<br />
ber<br />
from Imag<strong>in</strong>g<br />
laser<br />
-40MHz<br />
AOM<br />
polariz<strong>in</strong>g beam<br />
splitter cube<br />
50:50 beam<br />
splitter cube<br />
mirror<br />
spherical lens<br />
cyl<strong>in</strong>drical lens<br />
half-wave plate<br />
shutter<br />
ber coupler<br />
AOM<br />
+40MHz<br />
<strong>to</strong> beat lock<br />
setup<br />
additional<br />
resonant beam,<br />
e.g. for the<br />
small extra<br />
MOT beam for<br />
s<strong>in</strong>gle a<strong>to</strong>m<br />
detection<br />
f=50mm<br />
f=250mm<br />
f=60mm<br />
AOM<br />
f=100mm<br />
-114MHz<br />
optical<br />
isola<strong>to</strong>r<br />
AOM<br />
+114MHz<br />
f=50mm<br />
f=50mm<br />
Figure 7.34: Optical layout of the tapered amplifier<br />
MOT ber 1<br />
Tapered Amplier<br />
Zeeman slower<br />
ber<br />
AOM<br />
-80MHz<br />
MOT ber 3<br />
f=150mm f=100mm<br />
MOT ber 2<br />
arm shifts the laser frequency by −114 MHz, the AOM <strong>in</strong> the repump arm shifts the<br />
frequency by +114 MHz. Comb<strong>in</strong>ed this produces a frequency difference of 228 MHz,<br />
the hyperf<strong>in</strong>e splitt<strong>in</strong>g of the ground state of 6 Li. All three MOT beams <strong>and</strong> the Zeeman<br />
slower beam need a repump frequency component as well as the MOT frequency. The<br />
MOT arm <strong>and</strong> the repump arm are therefore recomb<strong>in</strong>ed on a 50:50 beam splitter cube.<br />
To align the polarization of the two beams, a half-wave plate is added <strong>to</strong> the repump<br />
arm.<br />
One of the output ports of the 50:50 beam splitter cube provides the power for<br />
the three MOT beams, the second one provides the power for the Zeeman slower beam.<br />
In the beam path for the MOT beams, a series of half-wave plates <strong>and</strong> polariz<strong>in</strong>g beam<br />
splitter cubes separate the beam <strong>in</strong><strong>to</strong> three beams. Each of these is <strong>in</strong>dividually coupled<br />
<strong>in</strong><strong>to</strong> a s<strong>in</strong>gle-mode polarization-ma<strong>in</strong>ta<strong>in</strong><strong>in</strong>g fiber. The beam of the second output port,<br />
used for the Zeeman slower beam, passes through another spherical telescope, aga<strong>in</strong> used<br />
<strong>to</strong> match the beam size <strong>to</strong> the active area of an 80 MHz AOM (IntraAction, AOM802).<br />
126