激光反射镜动态形变的测量

采用泰曼-格林干涉仪,测量了反射镜在高功率激光连续辐照下发生的热形变和镜背侧冷却水压造成的压力形变。测量结果表明,为缩小激光热形变和压力形变,降低激光功率密度和增大反射镜径厚比是必要的。碳化硅是较优秀的反射镜材料。

Measurement of dynamic distortion of laser mirrors

Thermal distortion of mirrors caused by high power CW laser radiation and pressure distortion by water-cooled back pressure have been measured using a Twyman-Green interferometer. Analysis of measurement results show that it is necessary to reduce the radiation power density and increase the diameter-thickness ratio of mirrors in order to minimize the thermal distortion by laser and pressure distortion. SiC is a good substrate material for laser mirrors with higher thermal conductivity, higher Young’s modules and lower coefficient of thermal expansion.