Effect of collisions on the shape of the coherent population trapping resonance detected by the Ramsey method

Abstract

We report on a theoretical model of the effect of coherent population trapping in alkali atoms in an optically thin gas cell with a buffer gas at a nonzero temperature in a pulsed laser field. The shape of the Ramsey resonance is analysed for two different temperature ranges, i. e. for a ‘cold’ atomic ensemble and for an ensemble of ‘hot’ atoms in a cell with a buffer gas. The influence of the hyperfine structure of the excited level on the shift of the central Ramsey resonance is investigated.

Influence of collisions on the effect of electromagnetic-induced transparency in cells of finite sizes with anti-relaxation coating of walls

“…At the same time, it is well known that taking into account the real atomic structure leads to qualitative features that do not allow description by means of a simple three-level model [68]. So, in the case of CPC, it turns out [69][70][71] that taking into account already one additional excited state in the theoretical description leads to significant differences from the predictions obtained when describing such phenomena in the framework of a threelevel lambda model.…”