周期性表面光学元件激光损伤阈值的拟合

Fitting Model of Laser-Induced Damage Threshold for Optical Elements with Periodic Surface

光学元件的激光诱导损伤阈值是衡量其抗激光损伤能力的重要指标。周期性表面光学元件具有良好的光学特性,在高功率激光系统中也有着潜在的应用,准确测定其激光诱导损伤阈值尤为关键。本文分析了激光诱导损伤阈值不确定度的主要来源,建立了激光诱导损伤阈值不确定度的计算公式,给出了减小激光损伤阈值不确定度的处理方法。结果表明:当激光的标定光斑半径为400μm、误差为10μm、激光能量误差为5%时,能量密度引入的不确定度为0。则激光损伤阈值的不确定度主要来源为损伤几率不确定度和线性拟合不确定度。通过增加每一能量级的测量次数,可以进一步减小激光损伤阈值的不确定度。

The laser-induced damage threshold of optical elements is a key indicator for measuring laser damage resistance.Optical elements with periodic surfaces have advantageous optical characteristics and potential applications in high-power laser systems.It is important to determine the laser-induced damage threshold accurately.In this paper,the main sources of uncertainty are analyzed,a calculation formula for the uncertainty of laser-induced damage threshold is established,and the processing methods for reducing the uncertainty of laser-induced damage threshold are provided.The results show that when the spot radius is 400μm,the error is 10μm,the laser energy error is 5%,and the uncertainty introduced by energy density is zero.Then,the main factors contributing to the uncertainty of the laser damage threshold are the uncertainty of the damage probability and that of the linear fitting.The precision of the laser-induced damage threshold can be further improved by increasing the number of measurements for each energy level.