Second optical harmonic generation in nonlinear crystals with a disordered domain structure

Abstract

A theory describing the second harmonic generation in nonlinear-optical crystals with random domains is developed. The theory takes into account the fluctuations of both the phase mismatch and the nonlinear coupling coefficient of the interacting waves. It is shown that, in such crystals, the maximal efficiency of fundamental-to-second harmonic conversion is low, and the dependence of the average intensity of the second harmonic on the fundamental intensity differs considerably from a square law.