图像处理在双波长激光诱导熔石英损伤增长中的应用

Application of image processing in dual-wavelength laser-induced damage growth of fused silica

利用图像处理方法对比研究了单波长辐照和双波长激光同时辐照下熔石英光学元件的损伤增长阈值。通过实时采集损伤图像和靶面光斑能量空间分布,获取损伤增长发生位置对应的能量密度。针对3ω单独辐照、3ω和1ω同时辐照下熔石英元件损伤增长的实验数据,比较分析了基于图像处理方法和传统损伤增长阈值R-on-1测量方法(国标)所得结果的差异。结果表明:本文采用的图像处理方法在研究小口径非均匀光斑辐照下的熔石英光学元件损伤增长阈值时,能解决传统损伤阈值测试中将能量密度分布非均匀光斑等效为均匀分布的平顶光斑带来的计算误差问题,有助于降低损伤(增长)阈值测量中的光斑口径效应。

The damage growth threshold of fused silica optical elements under single-wavelength irradiation and dual-wavelength laser irradiation was studied based on image processing methods. Through real-time acquisition of the damage image and the spot spatial energy distribution, the energy density at the location where the damage growth occurs was obtained. Aiming at the experimental data of the damage growth of fused silica optical elements under 3 ω irradiation, 3 ω and 1 ω simultaneous irradiation, the differences between the results obtained by the image processing method and the traditional damage growth threshold R-on-1 measurement method(GB) were compared and analyzed. The results show that the image processing method used in this paper can solve the calculation error problems caused by the traditional method that the non-uniform spot with energy density distribution is equivalent to the flat top spot with uniform distribution when the damage of fused silica optical element increases under the nonuniform spot of small aperture irradiation, and reduce the effect of light spot caliber in damage(growth) threshold measurement.