激光二极管端面抽运圆截面激光晶体的热效应

Thermal Effect of End-Pumped Laser Crystal with Circular Cross-Section

以求解热传导方程为基础,研究了端面抽运圆截面激光晶体内部温度场和抽运端热形变。通过对端面抽运激光晶体工作特点的分析,建立了晶体端面与外界非绝热边界条件;提出了热传导方程新的求解方法,得出了圆截面激光晶体内部温度场和抽运端热形变的解析表达式;研究了σ(空气传热系数与晶体导热系数之比)取不同值时,晶体中的温度场和抽运端热变形分布。结果表明,常用的晶体端面绝热假设与晶体实际工作状态不符。当σ=0,0.6和∞时,计算出晶体中的最大温升分别为165.2,135.7和40.1℃,晶体抽运端的最大热变形分别是0.66,0.55和0.22μm。

By solving heat conduction equation,the distribution of temperature field in laser crystal and the thermal distortion of laser crystal pumped-end were investigated,when the crystal with circular cross-section was end-pumped by laser diode.Analyzing the working environment,the more practical thermal model of laser crystal was built.The analytical expressions of temperature field and thermal distortion were obtained.Through numerical calculation,the influence of heat conduction conditions of crystal ends on temperature field and thermal distortion were studied.It was found that the widely used adiabatic conditions on laser crystal ends are not practical,and the proposed heat conduction conditions in the paper are more accurate.The results show that when parameter σ equals 0,0.6 or ∞,the maximum temperature rise in crystal is 165.2,135.7 or 40.1 ℃,and the maximum thermal distortion of crystal pumped-end is 0.66,0.55 or 0.22 μm,respectively.