本文设计了一种材料易得、适用于演示非线性光学现象的热透镜效应装置.低功率激光经凸透镜汇聚，在薄酱油介质中传输时产生热透镜效应，利用刀口法测量和软件拟合计算出激光高斯光束的半径，并结合光学矩阵运算得到酱油热透镜的焦距.由酱油薄膜位于凸透镜焦点前后时高斯光斑大小的变化，得出酱油介质在高斯光束照射下可等效为凹透镜，讨论了酱油浓度、厚度对热透镜效应的影响.本装置结构简单、性价比高，可用于本科的实验教学演示.

A thermal lens effect teaching demonstration device based on soy sauce optics is designed. By observing the phenomenon of thermal lens effect when low-power laser is converged through convex lens and transmitted in thin soy sauce medium，the radius of laser Gaussian beam is calculated by using knife edge method and software fitting，and the focal length of soy sauce hot lens is obtained by combining optical matrix calculation. Based on the changes in the size of the Gaussian spot before and after the soy sauce slice is located at the focal point of the convex lens，it is concluded that the soy sauce medium can be equivalent to a concave lens under the irradiation of the Gaussian beam. This device has simple structure，high cost performance，and can be used for undergraduate experimental teaching demonstration.