石英光学元件激光损伤修复形貌的优化  

Optimization of Morphology of Laser Induced Damage Mitigation Pit on Silica Optical Component

作　　者：周丽[1,2] 姜有恩[1] 韦辉[1] 范薇[1] 李学春[1] 

机构地区：[1]中国科学院上海光学精密机械研究所高功率激光物理联合实验室,上海201800 [2]中国科学院大学,北京100049

出　　处：《中国激光》2016年第6期110-118,共9页Chinese Journal of Lasers

基　　金：中国科学院青年创新促进会

摘　　要：针对三倍频光学元件后表面的损伤修复形貌,分别采用时域有限差分法(FDTD)和瑞利-索末菲(R-S)衍射积分法,来模拟不同形貌下元件修复区域内以及其后续的光场分布。结果表明,当修复坑截面轮廓线端点切线与光束传播方向夹角大于70°时,元件内部光强极大值小于1.66,修复效果优于其他角度。夹角为70°、宽200μm的抛物面型、圆锥型和圆台型凹坑的后续光强极大值小于1.46。但是当修复坑宽度较大如达到1mm时,圆台型凹坑的后续光强极大值高达9.31,且作用区间长。因此,考虑实际激光修复工艺的难度,夹角大于70°的圆锥型凹坑是石英元件后表面损伤修复的首选形貌。Aiming at morphology of laser induced damage mitigation pit on the rear surface of 3ω silica optical component, the mitigated area and its downstream intensity distributions with different morphologies are simulated by finite-difference time-domain method （FDTD） and Rayleigh-Sommerfeld （R-S） diffraction integral method, respectively. The results show that when the angle between the tangent line of endpoints on the section contour of the pit and incident light is over 70°, the maximum intensity inside the mitigated optics is less than 1.66, and mitigation effect is better than that of other angles. The maximum downstream intensities of a pit in shape of parabolic surface, cone and truncated cone are all less than 1.46 with an angle of 70° and a width of 200 μm. But when the width of pit increases to 1 mm, for instance, the maximum downstream intensity is as high as 9.31 and area with high intensity covers a long range. Thus, taking the difficulty of laser machining technology into account, a conical pit with an angle larger than 70° is the first choice for the damage mitigation on the rear surface of silica optical component.

关 键 词：激光技术 激光损伤修复 时域有限差分法 瑞利索末菲衍射积分 

分 类 号：TN249[电子电信—物理电子学]