以激光二极管端面抽运Nd:YAG激光器为例,采用有限元法数值计算了不同散热条件下晶体的温度分布;比较了两种散热方法(铜热沉加半导体制冷(TEC)器散热法和晶体侧面水流散热法)对晶体温度分布的影响,并提出晶体热透镜球差效应。根据温度分布的结果,采用光线追迹理论,定量比较两种散热方式对晶体不同径向位置热透镜焦距的影响。结果表明,采用铜热沉加半导体制冷器散热法时,晶体不同径向位置热透镜焦距较短,焦距差较小,球差效应较弱;采用晶体侧面水流散热法时,不同径向位置热透镜焦距较长,不同径向位置焦距差也较大,球差效应明显。最后模拟了两种散热方式下,晶体散热不对称时热透镜畸变的结果。 Taking laser diode end-pumped Nd: YAG laser as an example, the temperature distribution of the crystal under different heat dissipation conditions is calculated by the finite element method. Two heat dissipation methods (copper heat sink plus semiconductor cooling (TEC) Side water cooling method) on the temperature distribution of the crystal, and put forward the spherical lens thermal lens effect. According to the results of temperature distribution, ray tracing theory was used to quantitatively compare the influence of the two heat dissipation modes on the focal length of thermal lens in different radial positions. The results show that the focal length of the thermal lens in different radial positions of the crystal is shorter, the focal length difference is smaller and the spherical aberration effect is weaker when the copper heat sink and the semiconductor cooler are used for heat dissipation. When using the crystal side water cooling method, Lens focal length is longer, different radial position focal length difference is bigger, the spherical aberration effect is obvious. Finally, we simulate the results of the thermal lens distortion when the two kinds of heat dissipation modes are asymmetric.