Angular and temperature tuning characteristics of an optical parametric oscillator based on a KTiOPO4 crystal

Measurements were made of the wavelengths of the radiation generated in an optical parametric oscillator based on a KTiOPO₄ crystal. This was done for nonlinear elements with different cuts in the XY plane. The crystal was pumped with radiations from Nd³⁺:YAG and Nd³⁺:YA lasers. The temperature dependences of the output wavelengths were calculated and determined experimentally. There was a disagreement between the experimental and calculated angular and temperature tuning characteristics, which resulted from the influence of the absorption edge of the KTiOPO₄ crystal at the idler-wave tuning wavelengths 3.26—3.52 μm.