脉冲泵浦对准三能级Nd:YAG激光晶体热效应的影响

Impact of pulse pumped on thermal effect of quasi three level Nd: YAG laser crystal

对热效应影响严重的准三能级系统激光晶体采用脉冲激光泵浦,在泊松方程中引入矩形方波函数,考虑晶体侧面与冷却液之间的对流传热,以及晶体端面与外界的热传导,建立圆柱形Nd:YAG晶体的热传导模型和边界条件,采用有限元差分方法,求解变形后的泊松方程,得到激光晶体内温度的建立过程和临界稳定温度场分布。结果表明,采用脉冲泵浦方式能大大降低晶体内部的温度,有效减小晶体内部的热效应,为准三能级和三能级系统激光晶体的热效应研究提供了参考。

We apply pulse laser pumped to the laser crystal of quasi three level system with severe thermal effect.We also introduce a rectangular wave function into a Poisson equation.We further establish the thermal conduction model and its boundary conditions of a cylindrical laser crystal Nd ∶YAG,based on the convection heat transfer between crystal profile and coolant and the heat transfer between crystal terminal face and externality.We then employ finite element difference method to solve the deformed Poisson equation,and obtain the temperature construction process in the laser crystal and the critical stable temperature field distribution.Results show that pulse pump can significantly decrease the internal temperature of a crystal,and effectively reduce its internal heat effect.This paper provides a reference for the research on the thermal effect of quasi three level and three-level laser crystal.