熔石英亚表面缺陷附近光强分布的数值模拟

 熔石英亚表面缺陷对光场的调制是导致激光辐照场破坏的主要因素。采用有限元方法对熔石英亚表面缺陷（平面和锥形划痕）周围的光强分布进行了数值模拟。结果表明：划痕形状、几何尺寸、方位角、光的入射角等是影响划痕周围光强分布的主要因素；前表面划痕对光强的增强效果比后表面弱；在理想形状的划痕截面和表面同时发生内全反射时，平面划痕周围的光强增强效果明显。锥形划痕周围的光强分布为正确解释交叉划痕的夹角平分线附近的损伤提供了理论依据。

Numerical simulation of light intensity distribution in vicinity of defect on fused silica subsurface

The main factor of laser induced field damage is the modulation of light field by the defects on the fused silica subsurface. The finite element method is used to simulate the light intensity distribution in the vicinity of defects(planar and conical cracks)on the fused silica subsurface.The results show that light intensity distribution around a crack is determined by several factors, including crack morphology, geometry dimension, azimuth and incidence angle. The enhancement effect of a crack on the output surface is stronger than that on the input surface. When total internal reflection occurs at both the ideal morphology planar crack and the surface, high light intensification can occur in area adjacent to the planar crack. The light distribution in the vicinity of a conical crack prov