低功率激光作用下的热透镜效应

采用COMSOL Multiphysics 5.5软件构建的模型研究了透镜焦距变化与激光功率变化的关系，利用理论分析设计实验方案并确定热透镜焦距计算公式.通过实验探究了低功率激光作用下的热透镜效应，实现了低功率激光作用下热透镜效应的可视化，测得酱油透镜为热凹透镜；使用刀口法测量激光半径，得到热凹透镜的焦距，实验相对误差为3.6%；以焦距为热透镜效应的强度参照量，得到热透镜效应的强度与光功率呈正相关关系.

Thermal Lens Effect with Low-Power Laser

COMSOL Multiphysics 5.5 software was used to build a model to study the relationship between the change of lens focal length and the change of laser power.The experimental scheme was designed through theoretical analysis and the formula for calculating the focal length of the thermal lens was determined.Experiments were conducted to explore the thermal lens effect with low power laser,and the visualization of the thermal lens effect with low-power laser was realized.The soy sauce lens was measured as thermal concave lens.Using knife edge method and software fitting measurement of laser radius,combined with other data to calculate the focal length of the thermal concave lens,the measured relative error was 3.6%.Finally,taking the focal length as the intensity reference of the thermal lens effect,the measured intensity of the thermal lens effect was positively correlated with the optical power.