Single-Photon Atomic Cooling - Raizen Lab - The University of ...

master laser is dithered at 20 kHz. The signal from the differential photodi-
ode is mixed with the dithering frequency in a lock-in amplifier, resulting in
a dispersion signal, shown in Fig. 3.17. We lock to the dispersion curve cor-
responding to the F = 1 → 1/2 cross-over resonance because it is the most
Voltage
a b c d e f
Frequency
Figure 3.17: The dispersion curves correspond to the following transitions: a)
F = 1 → F ′ = 0, b) F = 1 → 0/1, c) F = 1 → F ′ = 1, d) F = 1 → 0/2, e)
F = 1 → 1/2, f) F = 1 → F ′ = 2.
prominent.
The hyperfine splitting of the F ′ = 1 and F ′ = 2 state is roughly
157 MHz, so the repump master laser frequency is locked 78.5 MHz below the
desired |F = 1〉 → |F ′ = 2〉 transition frequency. This beam is shifted to the
correct frequency with an 80 MHz AOM before being split by a PBSC and
sent to the upper and lower MOT as shown in Fig. 3.18.
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