The time-dependent population dynamics of hyperfine (HF) levels of n 2 p 3/2 states is examined for cyclic transitions in alkali atoms. We study a slow and cold atomic beam of Na (n = 3) and Cs (n = 6), taking into account the long interaction time of light with atoms (~200 μs) inside the resonant laser beam. Simple analytical expressions for the populations of the excited states and for the intensities of the absorption lines are derived for a three-level system model. We show that at moderate pump laser power the mixing of HF levels is sufficient to form a flow of population from a cyclic transition to partially open transitions. We discuss various phenomena associated with the evolution of optical pumping that cannot be explained by general analysis of two-level system model.
|Журнал||Optics and Spectroscopy (English translation of Optika i Spektroskopiya)|
|Состояние||Опубликовано - 2015|
Bruvelis, M., Cinins, A., Leitis, A., Efimov, D. K., Bezuglov, N. N., Chirtsov, A. S., ... Ekers, A. (2015). Particularities of Optical Pumping Effects in Cold and Ultra-Slow Beams of Na and Cs in the Case of Cyclic Transitions. Optics and Spectroscopy (English translation of Optika i Spektroskopiya), 119(6). https://doi.org/10.1134/S0030400X1512005X