基于损伤程度量化评估的光学薄膜元件激光损伤阈值测量方法  

Method for measuring laser damage threshold of optical thin film elements based on quantitative damage evaluation

作　　者：辛磊 杨忠明 孟君 刘兆军[1] Xin Lei;Yang Zhongming;Meng Jun;Liu Zhaojun(School of Information Science and Engineering,Shandong University,Qingdao 266237,China)

机构地区：[1]山东大学信息科学与工程学院,山东青岛266237

出　　处：《红外与激光工程》2024年第3期193-202,共10页Infrared and Laser Engineering

基　　金：国家自然科学基金项目(62175131);教育部联合基金项目(8091B032125);山东省重点研发项目(2020CXGC010204)。

摘　　要：光学薄膜元件是高功率激光器中的关键器件,其抗激光损伤的能力对整个激光系统的运行至关重要。精确测量薄膜元件激光诱导损伤阈值对提升激光器使用寿命与出光效率有着重要意义。提出一种新型激光损伤程度量化评估法,该方法对薄膜元件在不同能量密度下的激光损伤程度量化分析,通过损伤趋势拟合,评估激光损伤阈值。对激光损伤区域的量化采用图像超分辨白光显微干涉测量法,可实现纳米量级测量精度。通过仿真验证该测量方法可实现纳米量级损伤结构的三维重构,重构损伤区域误差小于0.01%。在实验部分,以激光谐振腔镜及窗口片为测试样品,无需大量重复性激光损伤实验,基于单片样品在一组不同能量密度激光束照射下产生的单次损伤结果实现测量,结果数据与S-on-1方法吻合,偏差小于0.5 J/cm^(2),两个样品多次测量结果的标准差分别为0.361 J/cm^(2)和0.064 J/cm^(2)。Objective Optical thin film components play a critical role in high-power lasers,and their ability to withstand laser-induced damage is crucial for the overall performance of the laser systems.Accurate measurement of the laser-induced damage threshold(LIDT)of thin film components is of great significance for improving the lifetime and output efficiency of lasers.However,the traditional test method for laser LIDT,based on the scheme outlined in GB/T 16601,involves evaluating the threshold value through damage probability,which requires numerous repetitive experiments and is both cumbersome and time-consuming.Moreover,the evaluation based on whether the damage occurs on the film surface introduces certain errors.The stability and reliability of the damage are influenced by factors such as laser stability,environmental disturbances,coating processes,and internal defects,which cannot be eliminated and affect the measurement results and accuracy.Additionally,probability statistics require testing many samples,resulting in high capital costs.Therefore,it is necessary to develop a fast and efficient method for measuring LIDT.Methods In this paper a novel method of quantitative evaluation of laser-induced damage degree(QELDD)is presented,for quantitatively assessing the degree of laser-induced damage in thin film components.The method involves analyzing the quantification of laser-induced damage at different energy densities and evaluating the LID threshold(LIDT)through damage trend fitting.To accurately quantify the laser-damaged area,super-resolution white-light interferometric measurement is employed,which ensures nanoscale measurement accuracy.Simulation results demonstrate that the proposed method allows for the three-dimensional reconstruction of nanoscale damage defects with a reconstruction volume error of less than 0.01%.Experimental samples,including laser resonator mirrors and window plates,were measured using this method,without repeating the laser damage experiments.The results were found to be consistent wi

关 键 词：光学薄膜元件 激光诱导损伤 损伤阈值测量 白光干涉技术 三维形貌测量 

分 类 号：TN247[电子电信—物理电子学]