熔石英表面铜颗粒污染激光诱导损伤  

Laser-induced damage of fused silica initiated by Cu contamination particles on surface

作　　者：苗心向[1] 程晓锋[1] 袁晓东[1] 吕海兵[1] 叶亚云[1] 贺少勃[1] 郑万国[1] 

机构地区：[1]中国工程物理研究院激光聚变研究中心,四川绵阳621900

出　　处：《强激光与粒子束》2010年第8期1740-1744,共5页High Power Laser and Particle Beams

基　　金：国家高技术发展计划项目

摘　　要：利用SAGA-S激光器输出的355 nm波长激光,研究了熔石英表面铜颗粒污染的激光损伤规律。采用磁控溅射的方式在洁净熔石英表面制备不同尺寸的颗粒状污染物,用1-on-1,10-on-1,20-on-1的方式测试经污染后的熔石英基底的损伤阈值,并采用光学显微镜观察损伤形貌、CCD在线测量损伤斑尺寸。结果表明:污染后的熔石英基底的损伤主要发生在后表面,而且以热烧蚀和热应力为主,基底的损伤阈值与熔石英前表面污染颗粒尺寸呈负指数关系,随后表面污染物颗粒尺寸的增大呈略微下降。前表面颗粒污染物诱导损伤斑尺寸为颗粒污染物尺寸的4倍,后表面颗粒污染物引起的损伤斑尺寸约为颗粒污染物尺寸的2倍。并绘出损伤斑尺寸与颗粒尺寸、辐照方式之间的关系。Fused silica was artificially contaminated to estimate its resistance against laser damage under 355 nm laser irradiation,which was produced by SAGA-S.Cu contamination was sputter-deposited through a mask until the thickness of the deposit reached 1 μm.The region surrounding each dot was characterized and photographed before illumination,after 1 shot,after 10 shots and after 20 shots（1-on-1,10-on-1,and 20-on-1 tests） by the Nomarski optical microscope and CCD on line,in order to track the initiation and growth of laser-induced damage upon repetitive illumination and to study the surface morphology of the damage.The experimental results show that the damage occurs mainly on the output surface of the contaminated fused silica through thermal ablation and thermal stress.The laser damage resistance of fused silica decreases exponentially with the increase of the size of Cu contamination on the input surface,while it decreases slightly with the size increase of the output surface contamination.For input surface contamination,the damage is four times the size of contamination,while for output surface contamination,it is only two times.The relation between contamination size and damage size irradiation mode and damage size was presented.

关 键 词：熔石英基片 激光诱导损伤 损伤形貌 损伤阈值 

分 类 号：TN249[电子电信—物理电子学]