在高功率Nd:YAG激光器中,由于部分抽运能量转化为热能沉积在介质之中,以及不均匀的冷却,导致激光介质内的温度分布不均匀,温度梯度进一步导致了介质内应力双折射、热透镜等热效应。模拟计算了Nd:YAG薄片激光介质在一定温度和应力分布条件下的应力双折射,并模拟计算了线偏振光通过该薄片介质后的退偏损失,计算结果与实验结果相符合。总结了一套计算晶体应力双折射的数值方法,并在此方法基础上编制了相应的MATLAB程序,为晶体应力双折射的消弱和退偏损失的补偿提供参考。 In high-power Nd: YAG lasers, due to partial pumping energy into heat deposition in the medium, as well as uneven cooling, leading to uneven temperature distribution within the laser medium, the temperature gradient further leads to stress birefringence in the medium, Thermal lens and other thermal effects. The stress birefringence of Nd: YAG lamellar laser medium under simulated temperature and stress distribution is calculated and the depolarization loss of linearly polarized light passing through the lamellar medium is simulated. The calculation results are in good agreement with the experimental results. A set of numerical methods for calculating the stress birefringence of the crystal was summarized. Based on this method, a corresponding MATLAB program was compiled to provide reference for the attenuation of the crystal stress birefringence and the compensation of the depolarization loss.