Influence of the polarization of radiation on the shape of resonances of coherent population trapping on fine-structure levels

The dependence of the shape of resonances of coherent population trapping (CPT) on rnagnetic sublevels of thallium atoms, forming a generalized A-system with the magnetic sublevels of the line-structure levels as lower ones,on the polarization of the radiation fields has been numerically studied. The cases of linear, elliptical, and circular polarizations have been considered. The shape and the number of CPT resonances For different polarizations have been compared. It has been concluded that the electromagnetically induced transparency can be changed by changing the polarization properties of the laser radiation. The possibility to decrease the number of observed resonances may be useful in high-resolution spectroscopy.