Optical pumping of He(23S) atoms by a color-center laser

Abstract

A color-center laser operating at 1.08 μm has been used to optically pump a thermal He(23S) atom beam via 23S→23P transitions. Even modest laser powers (∼10 mW) result in more efficient optical pumping than is obtained using a 400-W rf-excited helium resonance lamp. The laser also permits optical pumping via transitions to selected 23P fine structure levels.

Preparation of individual magnetic sub-levels of $^4$He($2^3$S$_1$) in a supersonic beam using laser optical pumping and magnetic hexapole focusing

“…To the best of our knowledge, we are the first to obtain a maximum efficiency > 90 % for optical pumping into M J = 0. The only previous attempt to selectively populate M J = 0 has been by Giberson et al [22] using linearly polarized light resonant with the 2 3 P 0 − 2 3 S 1 transition and propagating along the quantization axis.…”

“…A few years later, also the optical pumping of the 2 3 S 1 level of the 3 He isotope has been demonstrated using a similar setup [20,21]. The more recent use of narrowband laser radiation has proven to be particularly efficient for the optical pumping of He SP [22][23][24][25].…”

Optically polarizedHe3

“…14(a)) can be used to efficiently obtain a high electronic polarization in the 2 3 S state by depopulating, for instance, the Y 1 and Y 2 sublevels, whereas using the D 0 component depopulates only one sublevel and therefore yields a maximum polarization of 0.5 (Giberson et al , 1982; Wallace et al , 1995). In a similar way, optical pumping can efficiently depopulate selected sublevels of 3 He * atoms whenever ME collisions have a negligible rate, for instance at low temperature (see Fig.…”