高功率激光诱导光学元件损伤阈值测量的不确定度分析

 激光诱导损伤阈值作为一实验参量，对其结果作不确定度分析有利于激光工作者在某个精度范围内获知该参量的信息。从激光损伤和损伤阈值定义出发，分析了基于ISO11254的损伤几率测试法测试激光诱导损伤阈值的不确定度来源，包括激光能量测量、激光光斑有效面积测量、各能量密度处损伤几率的计算以及对损伤几率点进行直线拟合这4个方面。并利用统计学原理和线性拟合等理论对这4个方面引起的不确定度分量及最终测试结果的相对合成不确定度进行了计算。以1 064 nm高反薄膜样品为例，分析表明：损伤几率点的计算和几率图中损伤几率的直线拟合是损伤阈值测试结果不确定度的主要来源，当样品的损伤阈值为7.79 J/cm²时，这两种因素引起的相对不确定度可分别在4%和18%左右，损伤阈值的相对合成不确定度达18.72%。

Analysis of uncertainty of measured laser-induced damage threshold

The laser-induced damage threshold (LIDT) is regulated by the ISO11254 standard based on the damage frequency method, and its uncertainty information is useful for the researchers. Analysis shows that the origins of the uncertainty, which valves can be solved by statistics and linear fit theory, lie in measurements of the energy and effective area of the laser beam, calculation of the damage probability in a limited fluence range and the linear fit process in the damage frequency scheme. At last, an 1 064 nm HR thin-film sample was tested in this work. The results indicate that the last two origins are the major uncertainty of the LIDT, they are respectively about 4% and 18% while the LIDT is 7.79 J/cm~2, and the total relative combined uncertainty of LIDT of the sample reaches 18.72%.