激光诱导光学材料后表面损伤的数值模拟

 采用3维时域有限差分方法和完全匹配吸收层，模拟了长方体缺陷在熔石英前后表面时对入射激光为TM波的调制作用，绘出了截面上的电场强度分布及最大电场强度随熔石英深度变化的曲线，并进行了比较和分析。结果表明：缺陷在前表面上时，后表面附近的最大电场强度2.522 41 V/m大于缺陷附近的1958 83 V/m；缺陷在后表面上时，材料中的最大电场强度为2.799 38 V/m，且出现在后表面附近。无论该缺陷在前表面还是在后表面，最大电场强度都是出现在后表面附近，表明光学材料的后表面在一定程度上更容易被损伤。

Numerical simulation of laser-induced damage on rear surface of optical material

The three-dimensional model of cubic defect has heen built. 3D finite-difference time-domain method and perfectly matched layer are used. The modulation caused by TM incident laser is simulated while the cubic defect is on the front surface or on the rear surface of fused silica. Sectional electric field intensity distribution and the maximal electric field intensity variance with depth in fused silica are illustrated. The electric fields for materials with a defect on input or output surface have been compared and analyzed. The maximal electric field intensity 2.522 41 V/m near the rear surface is larger than 1.958 83 V/m near the defect when the cubic defect is on the input surface. When the cubic defect is on the output surface, the maximal electric field intensity 2.799 38 V/m in the m