为了研究半导体激光器端面抽运激光晶体产生的热效应问题,采用解析分析的方法研究端面抽运激光晶体的温升以及热形变量的大小。通过激光晶体工作特点分析,考虑到Nd:GdVO₄晶体热传导各向异性的特点,采用各向异性传热的Poisson方程,得出了超高斯光束端面抽运Nd:GdVO₄晶体温度场以及热形变场的一般解析表达式。并定量分析了超高斯光束不同阶次、不同光斑尺寸抽运时对于Nd:GdVO₄晶体温度场以及热形变场的影响。结果表明,若半导体激光器的输出功率为30W,光学聚焦耦合器传输效率为85%,5阶超高斯光束沿中心端面抽运掺钕离子原子数分数为0.012的Nd:GdVO₄晶体,抽运面可获得419.3℃的最大温升,并产生0.711μm的热形变。该结果对估算Nd:GdVO₄晶体热焦距变化范围以及进行热不敏谐振腔设计具有理论指导作用。

In order to study the thermal effect of laser crystal end-pumped by diode lasers,the temperature rise and thermal distortion on pumped-face of the laser crystal were analytically studied.After analyzing the working characteristics of the laser crystal,taking into account of the aeolotropism of heat conduction of Nd:GdVO₄ crystal,the general analytical expressions of the temperature field and thermal distortion field of Nd:GdVO₄ crystal end-pumped by super-Gaussian beam were obtained based on the Poisson equation for aeolotropic heat conduction.The effect of different orders and spot size of super-Gaussian beam on the temperature field and the thermal distortion field of Nd:GdVO₄ crystal was quantitatively analyzed.The results show that the maximal temperature rise and thermal distortion on the pumped-face of Nd:GdVO₄ crystal doped with 0.012 (atomicity fraction)neodymium ion are 419.3℃ and 0.711μm respectively with the fifth-order super-Gaussian beam central-end-pumping,if the output power of diode laser is 30W,the transmission efficiency of the optical focusing coupler is 85%.The results have the theoretical instruction for estimating the thermal focus lens of Nd:GdVO₄ crystal and designing the heat insensitive resonant cavity of lasers.