Heat-coupled Gaussian continuous-wave double-pass optical parametric oscillator: thermally induced phase mismatching for periodically poled MgO:LiNbO_3 crystal

In this paper, a model describing the thermal effects on the optical parametric oscillator (OPO) of Gaussian continuous waves in double-pass cavities is presented. Eight equations, including forward and backward nonlinear waves, heat, and thermally induced phase mismatching equations, were coupled and solved simultaneously to investigate the effect of heat generation on the OPO’s efficiency. The model was applied for a periodically poled MgO:LiNbO3 crystal with an excellent agreement with experimental data. The numerical calculations have been carried out by a homemade code written in Intel FORTRAN, which used a finite difference method.