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