On the influence of laser beams diameters on sub-Doppler resonances of the saturated absorption

Interaction of the counter-propagating coaxial laser beams with mutually orthogonal circular polarizations and various diameters was investigated in the rarefied gas medium at the optical transitions from the long-lived atomic level. The experiment was realized on the D-2 line of cesium atoms. It is shown that by the choice of different diameters of laser beams one can essentially increase the contrast of sub-Doppler resonances of saturated absorption on noncyclic optical transitions. Analysis of experimental results is carried out on the basis of the developed theoretical model.