A self-consistent model of second harmonic generation of laser radiation in the periodically poled nonlinear-optical crystal conditioned by its nonuniform heating

Abstract

We introduce a self-consistent model that describes the process of the second harmonic generation (SHG) of the laser radiation in a nonlinear-optical crystal in conditions of its nonuniform heating induced by optical absorption. A periodically poled crystal pumped by the pulse laser radiation focused into its center was considered. The iteration procedure of solving the SHG problem relies on the interrelated solution of two equation systems describing the temperature dependent SHG and the heat conduction processes. The heat sources are represented by the absorbed power of both pump and generated radiations. Along with the absorption of pump and generated waves the diffraction effect was also taken into account. Eventually the resulting distribution of the crystal temperature should correspond to the radiation intensity distributions of pump and second harmonic.