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

2 P3/2 (J=3/2)
2 S1/2 (J=1/2)
F=3
F=2
F=1
F=0
F=2
F=1
266.65 MHz
156.95 MHz
72.218 MHz
6.835 GHz
Repump
m -3 -2 -1 0 1 2 3
F
Figure 2.17: MOT and repump transition in 87 Rb. The MOT transition drives the atoms
from |F = 2〉 to |F ′ = 3〉, the repump drives the |F = 1〉 to |F ′ = 2〉 transition.
2 P3/2 (J=3/2)
2 S1/2 (J=1/2)
F=1/2
F=3/2
F=5/2
F=3/2
F=1/2
4.4 MHz
228.2 MHz
Δ
unresolved excited
state structure
Δ
Repump
m F -3/2 -1/2 1/2 3/2
Figure 2.18: MOT and repump transition in 6 Li. The MOT transition drives the atoms
from |F = 3/2〉 the unresolved excited state. The repump transition goes from the
|F = 1/2〉 to the excited state.
on the other hand requires a significant amount of repump power. It is therefore ad-
vantageous to use the repump light as a cooling transition as well. This requires a total
of six repump beams co-propagating with the MOT beams and the polarization to be
identical to the MOT beam.
Typical phase-space densities in a MOT are on the order of ρ ≈ 10 −6 . The
25
MOT
MOT