Characteristics of the dynamics of stimulated Raman scattering in a gas excited by a train of short pulses

An investigation was made of the dynamics of stimulated Raman scattering (SRS) in compressed hydrogen excited by a train of short pulses. The observed features of the SRS dynamics were attributed to the competition between the focusing influence of an SRS lens and the defocusing influence of a thermal lens generated as a result of relaxation of an excited state. The method employed made it possible to determine the polarizability of the vibrational state of the molecules excited by SRS.