Coherent effects in the field of elliptically polarized light

Abstract

In the present communication we report on the investigation of the effect of elliptically polarized laser light exciting the Fg=3 Cs D2 absorption line. Coherent resonances in Cs have been studied, obtained in Hanle configuration by scanning of magnetic field parallel to the light propagation direction. The resonances were investigated depending on the polarization of the irradiating light field. It has been observed that for linear polarization dark resonances in the fluorescence are registered, while for circularly polarized light, bright resonances are obtained, probably due to stray orthogonal magnetic field. For elliptical polarization a narrow peak appears superimposed on a broader dip. Theoretical description has been made, which shows that at elliptical polarization and orthogonal magnetic field in the case of weak light fields, a single peak in the excited state population is observed, while strong fields lead to the splitting of this peak into two peaks. The presence of both weak and strong light fields, probably due to reflection of the light beam on the cell walls, could lead to the experimentally observed fluorescence behaviour.