建立了矩形激光晶体的热传导模型。通过充分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,建立了更为合理的边界条件。利用有限元差分法求解泊松方程,得到激光晶体内温度和温度场分布。研究结果表明,在考虑晶体的侧面对流和端面导热的情况下,得出了更符合实际的晶体温度场分布,计算的热焦距与实验测量结果更为吻合。 The heat conduction model of rectangular laser crystal was established. By fully considering the convection heat transfer between the side of the crystal and the coolant, and the heat conduction between the crystal face and the outside, a more reasonable boundary condition is established. Finite element difference method is used to solve the Poisson equation to get the temperature and temperature distribution in the laser crystal. The results show that the temperature distribution of the crystal is more suitable when considering the side convection and the thermal conductivity of the end face. The calculated thermal focal length is in good agreement with the experimental results.