对微片激光晶体的实际工作特点进行分析, 根据热容激光器的管理模式, 建立抽运和冷却阶段的晶体热模型。然后引入变热传导系数对方程进行求解, 分别得到激光二极管(LD)单端抽运和冷却时热容激光器温度场的表达式。并对光斑半径和抽运时间这两个影响晶体温度场的因素进行了分析, 计算结果表明：当Nd∶YAG晶体热导率分别为常量和变量时, 其抽运端面的最大温升分别为459.24 ℃、535.78 ℃。其中晶体钕离子的质量比为1.0%, 微片尺寸为Φ20 mm×1 mm, 抽运功率为60 W, Nd∶YAG晶体对入射抽运光的吸收系数是910 m-1, 超高斯光束阶次为3, 抽运光的光斑半径为800 mm。计算分析结果对LD端面抽运固体热容激光器谐振腔的设计具有借鉴意义。

According to the management mode of the heat capacity laser, the crystal thermal model of the pump stage and the cooling stage are established respectively by analyzing actual working characteristics of microchip laser crystal. Then the equation of the heat transfer coefficient is introduced and the expressions of the temperature field of heat capacity laser are obtained with the status of side-end-pumping and cooling of laser diode (LD). The factors of spot radius and pump time that influencing the crystal temperature field are analyzed respectively. The results show that when the thermal conductivity of Nd∶YAG crystal is constant and variable, the maximum temperature rises of pump end face are 459.24 ℃ and 535.78 ℃,respectively. The mass ratio of neodymium ion in the crystal is 1.0%. The size of microchip is Φ20 mm×1 mm. The pump power is 60 W. The absorption coefficient of Nd∶YAG crystal is 910 m-1 . The super-Gaussian beam order is 3 and the pump light spot radius is 800 mm. The analysis results are helpful to the design of LD end-pumped solid-state heat capacity lasers resonator.