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.

• Received 18 January 1990

DOI:https://doi.org/10.1103/PhysRevA.41.4989