Pumping efficiency in an optically pumped rubidium beam with σ+π linearly polarized counterpropagating lasers
Jin Woo Jun, Ho Seong Lee
We investigate the population differences between ground-state hyperfine levels (${5S}_{1/2},F=2$ and ${5S}_{1/2},$ $F=1$) of an optically pumped ${}^{87}\mathrm{Rb}$ beam in a static magnetic field, taking into account the various kinds of atomic coherence (Zeeman, hyperfine, and optical). The pumping lasers are monochromatic and in resonance with the ${(5S}_{1/2},F=1\ensuremath{\leftrightarrow}{5P}_{1/2}{,F}^{\ensuremath{'}}=1)$ transition. By varying the polarization configuration of the pumping lasers, we find that the pumping efficiency is substantially enhanced when a $\ensuremath{\sigma}$-polarized laser and a $\ensuremath{\pi}$-polarized laser are counterpropagating. In this case, the pumping efficiency remains high even in a weak magnetic field, which explains qualitatively experimental data reported previously from a cesium beam experiment.
Physical Review A•Nov 1, 1998•4 citations