We describe optically pumping a beam of sodium atoms to >96% ms and >92% ms, mI state selection. (We have accurately measured the population of every ms, mI state in the optically pumped beam.) For the optical pumping both ground hyperfine states are pumped, using single-mode cw dye-laser radiation tuned to the 3S½–3P½ transition that is phase modulated in a LiTaO3 crystal to produce first-order sidebands at approximately the 1772-MHz hyperfine splitting of the ground state. The z-directed optical pumping is performed in a z-directed magnetic field of ˜5 G. The state-selected atoms then move, in ˜1 cm, into an ˜200 G, z-directed field. The downstream probe laser beam is scanned through the 3S½ (ms, mI)→ 3P3/2 (ms′, mI) transitions, which are spectroscopically resolved at 200 G, and the fluorescence intensities portray the residual populations in each of the eight 3S½ states.
© 1991 Optical Society of America
Gregory W. Schinn, Xianming L. Han, and Alan Gallagher, "Production and diagnosis of a highly spin-polarized Na beam," J. Opt. Soc. Am. B 8, 169-173 (1991)