中文摘要：

光学元件的亚表面损伤直接影响其使用性能和抗激光损伤阈值等重要指标，而造成这些危害的根本原因是损伤引入的光散射。针对K9玻璃光学元件建立损伤模型，结合时域有限差分（FDTD）算法，模拟研究了会聚入射光被光学元件亚表面缺陷如微裂纹、气泡等调制后的光场分布以及光沿纵深方向扫描时探测器所接收的亚表面损伤引入的散射光强变化。研究结果对探索光学元件亚表面损伤的测量方法有重要的理论指导意义。

英文摘要：

There is a serious effect directly for optical element sub-surface damage to optical performance and laser damage threshold in the application, and the primary cause is due to light scattered by subsurface damage. Aim to K9 glass optical element, the simulation model is built. By using finite difference time domain （FDTD） method, the light field distributions, which are the incident light modulated by subsurface micro-cracks and bubbles, are simulated, and the scattering light intensity variation received by detector is analyzed. The results have important theoretical guideline to further study the measuring methods of optical components subsurface damage.