Second harmonic generation of the laser radiation in biaxial crystal KTiOPO₄ with regular domain structure

The theory of the laser radiation second harmonic generation in biaxial crystals with periodic domain structure has been developed. In crystals a sign of the tensor of square-law nonlinear susceptibility has been changed when transition from domain to domain is occurred. Comparison results of the numerical calculation with experimental data for efficiency of the second harmonic generation process in biaxial crystal KTiOPO₄ has been shown their coincidence under small value of the powers of the general radiation. It is revealed that dependency of the conversion coefficient of radiation in the second harmonic with growing the length of the crystal is saturated. (authors)