Hannover 2020 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 35: Cold Molecules I (joint session MO/Q)
Q 35.1: Talk
Wednesday, March 11, 2020, 14:00–14:15, f102
Optical pumping of metastable helium: state purification and spin-state selection — •J. Guan, T. Sixt, A. Tsoukala, F. Stienkemeier, and K. Dulitz — Institute of Physics, University of Freiburg, Herman-Herder-Str.3, 79104 Freiburg, Germany
Discharge and electron-impact excitation lead to the production of metastable helium atoms in two metastable states, 23S1 and 21S0. However, many applications require purified beams containing only one of these species. For atom magnetometers and spin-controlled collisions, even magnetic quantum state selection is required.
Recently, we have successfully applied optical quenching via the 41P1 ← 21S0 transition at 397 nm to fully deplete the 21S0 population in a 4He gas beam.1 Equipped with a tunable laser at 1083 nm for excitation of 23S1 → 23P transitions, we continue to make progresses on preparing the spin-labelled 23S1 state after optical quenching. In this talk, I will show our results on the optical quenching of He (21S0) and on the optical pumping of He (23S1). The spin-controlled metastable He atoms (23S1, mJ = 1, 0 or -1) are an ideal source for studying cold and controlled reactive collisions and I will outline possible experiments using this setup.
Reference: 1. Guan et al., Phys. Rev. Appl. 11, 054073 (2019).