光学玻璃表面裂纹是改变自身光场, 影响抗激光损伤能力的重要因素之一。研究熔融石英玻璃表面裂纹诱导激光损伤的增强效应, 基于光场传播理论和有限元方法, 讨论微裂纹对入射光场的调制作用, 对熔石英表面裂纹周围的光场分布进行数值模拟; 探讨了熔石英入射表面与出射表面裂纹引起的光强增强效应, 给出径向裂纹周围光场的分布; 定量研究光场调制的光强增强因子和裂纹结构参数(裂纹角度、裂纹宽度以及裂纹深度)的关系, 为场致损伤提供理论参考。

Optical glass surface cracks can change the optical field in materials, which play a significant role in the impact of laser damage resistance of optical glass. This paper study on the enhancement effect of laser damage induced by fused quartz glass surface cracks. The theory of optical field propagation and the finite element method are used to study the modulation of incident optical field by micro-cracks. First, light field distributions near fused quartz surface cracks are numerical simulated. Then, the enhanced effects of light intensity caused by cracks on fused quartz incidence surface and emergent surface are analyzed. The distribution of optical fields around the radial cracks are shown. Third, the relationship between crack structure parameters (crack angle, crack depth and crack width) of cracks and the light intensity enhancement factor is studied quantitatively. The results can provide theoretical reference for field induced damage.