纳秒激光辐照划痕表面熔石英的热应力模型  

Thermal Stress Model of Fused Silica with Scratch Surface Irradiated by Nanosecond Laser

作　　者：卢强 许卫洪[2] 王绶玙[1] 孔艳[1] 刘诚[1,3] Lu Qiang;Xu Weihong;Wang Shouyu;Kong Yan;Liu Cheng(Computational Optics Laboratory,School of Sciences,Jiangnan University,Wuxi 214122,Jiangsu,China;College of Internet of Things and Artificial Intelligence,Wuxi Vocational Institute of Commerce,Wuxi 214153,Jiangsu,China;Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China)

机构地区：[1]江南大学理学院计算光学实验室,江苏无锡214122 [2]无锡商业职业技术学院物联网与人工智能学院,江苏无锡214153 [3]中国科学院上海光学精密机械研究所,上海201800

出　　处：《中国激光》2023年第12期134-142,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(12004141);江苏省自然科学基金(BK20200588)。

摘　　要：为了研究激光辐照含有表面划痕的熔石英的热应力特性,基于电磁场、热传导及弹塑性力学理论,建立了适用于不同表面缺陷类型的纳秒脉冲激光辐照熔石英的热应力数值模型。利用该模型计算得到平滑表面和划痕表面熔石英在激光辐照后的温度场分布和应力场分布,并通过搭建的激光损伤测试及应力在线测量系统实验验证了所建模型。研究结果表明,熔石英的表面结构引起的光场调制会导致激光辐照后熔石英内部应力增强,并且应力大小与其表面结构尺寸密切相关。研究结果不仅有助于分析含有表面划痕的光学元件的激光损伤机理及残余应力,而且能够对激光加工的热应力调控提供理论依据。Objective Lasers are widely used in laser processing,laser medical treatment,optical communication,inertial confinement,and nuclear fusion.With the continuous development of laser technology,the output power and single-pulse energy of lasers are increasing.Under high energy density conditions,the laser damage resistance of optical elements is one of the main factors affecting further development of high-power laser systems.Laser-induced damage shortens the working life of optical elements and considerably reduces the peak power output of high-power laser systems.Therefore,it is necessary to investigate the damage characteristics of optical materials under high-power laser irradiation.The mechanism of laser damage is very complicated and involves several physical processes,such as laser energy deposition,temperature and stress changes,and material phase transformation.During these processes,stress leads to damage of optical components,such as pits and cracks,and the residual stress in optical components increases the difficulty of laser repairing optical components.Therefore,it is crucial to investigate the thermal stress characteristics of laser-irradiated optical materials.However,current research on thermal stress properties is focused on optical materials with smooth surfaces,and the results are not applicable to uneven-surface optical elements with various defects and periodic structures.The thermal stress characteristics of complex surfaces under laser irradiation should be analyzed using thermodynamic models and related experiments.Methods Based on the theories of electromagnetic fields,heat conduction,and elastic-plastic mechanics,thermal stress numerical models of optical materials are established for different types of nanosecond pulse laser irradiation to investigate the uneven-surface thermal stress characteristics of optical materials under laser irradiation.This thermal stress numerical model can simulate the temperature and stress field distributions of optical materials with smooth and uneven surfa

关 键 词：激光技术 激光损伤 应力分布 表面划痕 光场调制 

分 类 号：O343.6[理学—固体力学]