Strong-interaction approximation in the theory of second harmonic generation of intense short laser pulses

The method of strong interaction of nonlinear waves has been developed to a nalyse the second harmonic generation of intense laser radiation in the tra nsient regime. Analytic solution for frequency conversion efficiency - taki ng into account the pump radiation depletion, influence of phase mismatch, dispersion of group velocities and higher nonlinearities - has been first o btained. A comparison of theoretically derived results and known experiment al data has been conducted, and a general agreement of these results has be en obtained. The optimal conditions of the second harmonic generation of ne odymium laser radiation into femtosecond pulse duration range have been det ermined.