以半解析热分析理论为基础, 研究了超高斯分布激光二极管(LD)端面抽运背冷式方形Nd∶GdVO4微片晶体的热效应。通过对激光晶体工作特点的分析, 建立热模型, 利用新的热传导方程求解方法, 得出了背冷式方形Nd∶GdVO4微片晶体内部温度场、热形变场的半解析计算表达式。研究结果表明, 当使用输出功率为700 W的LD(超高斯阶次为4)端面中心入射背冷方形Nd∶GdVO4晶体(晶体掺钕原子数分数为1.2%)时, 在抽运端面中心获得69.6 ℃最高温升和74.1 nm最大热形变量, 与实验结果一致。得出的方法可以应用到其他激光晶体热问题研究中。

Based on the theory of semi-analytical thermal analysis, thermal effects within a diode-end-pumped cubic Nd∶GdVO4 microchip crystal cooling from back surface are investigated. Based on the analytical theory of aeolotropies, a thermal model that matches the actual working state of the microchip crystal is established. Temperature and thermal distortion fields within the microchip crystal are analyzed and general solutions of the temperature and thermal distribution fields of the crystal are obtained by using a novel method to solve the heat conduction equation of anisotropic medium. Research results show that a maximum temperature rise of 69.6 ℃ and a maximum thermal distortion of 74.1 nm can be obtained in the center of the pump face when the Nd∶GdVO4 microchip crystal doped with 1.2% Nd3+ is end pumped in the center of the front end face by LD (the super-Gaussian order is 4) with an output power of 700 W, which is in agreement with experimental results. The method can be applied to other thermal analyses of laser crystals.