'Temporal and spatial evolution of collision-induced stimulated effects in alkali atoms

A computational study of the optical propagation of Stokes light in a collisionally broadened three-level V-system Raman amplifier is presented. The Stokes light consists of two distinct spectral components: off-resonance stimulated Raman scattering and on-resonance stimulated fluorescence. These two signals are induced by collisional transfer of population from the P-2(3/2) excited state to the P-2(1/2) state. The intensity dependence of these effects on the buffer gas and intensity and detuning of the exciting radiations is calculated. In the calculations the probe signals and spontaneous scatterings were used to induce the stimulated signals. We have carried out the calculations over physically realistic propagation distances. The theory was compared with our experimental work and the results of the numerical analysis are used to explain some events observed in the experiments in which the physical mechanism has not yet been understood.