Optical Pumping with Lasers

Thomas R. Carver

Pierre‐Luc Tremblay, Claude Jacques

Two-laser optical pumping schemes show great promise for atom preparation since they can act as a nearly perfect state selector. This paper presents a new theoretical model to evaluate the pumping efficiency of two-laser pumping schemes, taking into account optical, ground and excited states hyperfine and Zeeman coherences, neighboring transitions, and fluctuating laser fields. The model is used to predict the optical pumping efficiency of two lasers with Lorentzian spectral profiles on a beam of cesium atoms. The particular laser intensities and linewidths that optimize the optical pumping efficiency and rate are calculated.

M. Elbel, Christian Larat, Pierre-Jean Nacher +1 more

We have operated an electrooptical modulator to generate sidebands to the laser used for optical pumping of a helium-3 gas. Spreading the laser power over the Doppler absorption profile of the metastable helium atoms can enhance the efficiency of the optical pumping process. This improvement is discussed in terms of velocity changing collisions and compared to the result of a velocity selective optical pumping experiment.

Robert A. Bernheim, Ernst K. Franke

Pierre Tremblay, Jean Beaubien, A. Michaud +1 more

Optical pumping of an atomic vapor with low-power lasers often results in low pumping efficiency because of the narrow laser linewidth. Broadening of the laser spectrum by frequency modulation (FM) ensures the contribution of atoms from all velocity classes. We numerically evaluate the difference between the population enhancement for a vapor pumped with a modulated laser and that with a nonmodulated laser. The most efficient modulation scheme among those considered is FM with narrow-band Gaussian noise. The achieved optical pumping enhancement depends on laser linewidth and available power.