Efficiency of optical frequency conversion in inhomogeneous nonlinear media

Results are presented of an analysis, carried out using the fixed-intensity approximation, of the nonlinear interaction of optical waves in media with regular inhomogeneities. It is found that, if the intensity of the fundamental radiation is fixed, the efficiency of second harmonic generation in such media saturates and, in parametric processes, the threshold pump intensity increases. Moreover, the inhomogeneities of the medium increase the duration of the excited pulses and broaden the parametric locking band. Parametric amplification is also analyzed for the case of statistically inhomogeneous media.