对三种具有商业价值的非线性光学晶体——LBO,KTP,BBO热透镜效应进行了分析研究,通过具体理论计算,给出了三种非线性光学晶体的热透镜焦距在保持输出功率没有变化的情况下随入射到晶体表面的光斑大小的变化曲线,并且理论计算出在平均功率为20 W的绿光激光器中KTP晶体在入射基频光斑w=368 μm的热焦距为852 mm,实验中测得的M2值与理论计算吻合较好。

A discuss on the thermal-lens effect of three nonlinear optical crystals of great commercial value——LBO, KTP and BBO was given in the paper. The curve that the focal length of three crystals mentioned above varying with the spot size of fundamental frequency delivered on the face of the nonlinear optical crystals was also given. At the same time, KTP thermal focal length was calculated 852 mm on the condition that the incident spot size w=368 μm according to 20 W output green laser which used KTP crystal as its double frequency crystal, which agrees well with the experimental data.