Effect of the pressure of light on the shape of saturated-absorption resonance in a gas

The effect of a force of resonance pressure of light on the amplitude and frequency properties of saturated-absorption resonance in a gas of two-level atoms was studied. On the basis of numerical solutions of the Liouville and Fokker-Planck equations, dynamics of changes in the velocity-distribution function of an ensemble of atomic particles, depending on the saturation parameter and time of their interaction with a strong field of light, was evaluated. The shape of a resonance line, related to saturated absorption, and its location relative to the frequency of the atomic transition were determined taking into account the dynamics of the distribution function. The results of the calculations are compared with the experimental data.