高功率CO_2激光作用下硅镜热畸变的动态过程研究

The investigation of the dynamic process on thermal distortion of silicon mirror

以光学干涉方法，实验研究了在ＣＯ２激光束入射在硅镜上，硅镜热畸变的动态过程。在变形之初，硅镜镜面的位移量变化迅速。对于一面７０ｍｍ，厚８ｍｍ的硅镜，吸收激光功率１４０Ｗ，作用时间４ｓ时最大挠变形０７６μｍ。这对于高功率短波长激光器而言是不可忽略的。

Used optical interferometry,the dynamic process of thermal distortion of the silicon mirror was investigated experimentally,while the 2kW CO 2 laser beam is used as incident source.The diplacement of surface of the silicon mirror is varying raplidly in the beginning of the distortion.For a silicon mirror,that is 70mm in diameter and 8mm in thickness,the maximum deflection introduced by thermal distortion is 0.76μm,when the absorbed laser power is 140W and the acting time is 4s.It is not an negligible problem to a high power short wavelength laser.