355 nm和1064 nm激光辐照下DKDP晶体的表面损伤特性  

Investigating surface damage characteristics in DKDP crystalsby laser irradiation at 355 nm and 1064 nm

作　　者：史晋芳[1] 邱荣[2] 郭德成 周磊[2] 蒋勇[2] 周强[2] 余健 陈元攀 谢准 Shi Jinfang;Qiu Rong;Guo Decheng;Zhou Lei;Jiang Yong;Zhou Qiang;Yu Jian;Chen Yuanpan;Xie Zhun(Key Laboratory of Testing Technology for Manufacturing Process of Ministry of Education,Southwest University of Science and Technology,Mianyang 621010,China;Joint Laboratory for Extreme Conditions Matter Properties,Southwest University of Science and Technology,Mianyang 621010,China)

机构地区：[1]西南科技大学制造过程测试技术教育部重点实验室,四川绵阳621010 [2]西南科技大学极端条件物质特性联合实验室,四川绵阳621010

出　　处：《强激光与粒子束》2023年第7期25-32,共8页High Power Laser and Particle Beams

基　　金：国家自然科学基金委员会与中国工程物理研究院联合基金项目(U1530109);国家自然科学基金项目(11972313)。

摘　　要：利用Nd:YAG激光器研究了DKDP晶体元件在激光辐照下的表面损伤特性,对比研究了355 nm和1064 nm激光辐照下晶体元件的表面损伤形貌,分析了每种损伤形貌对应的前驱体和损伤机制。研究结果表明:相对于体损伤,晶体的表面损伤更加复杂,在脉宽约10 ns、损伤概率小于等于50%的激光能量密度辐照下,DKDP晶体的表面损伤主要有带坑底空腔损伤坑、表面损伤裂纹、平底损伤坑、表面烧蚀四种典型形貌。通过光学显微镜和扫描电子显微镜的成像和分析发现:带坑底空腔损伤坑和表面损伤裂纹的前驱体都是晶体体缺陷,平底损伤坑的前驱体则可能是表面加工裂纹、裂纹内碎屑、表层体缺陷等中的一种或多种,表面烧蚀主要由表面污染和浅表层缺陷形成。与熔石英光学元件一样,表面损伤仍然是晶体元件抗激光辐照损伤的薄弱环节。The surface damage characteristics in DKDP crystals under laser irradiation at 355 nm and 1064 nmwere studied and compared by using a Nd:YAG laser.The damage precursors and mechanisms corresponding to eachdamage morphologies were analyzed.The damage results reveal that the surface damage in DKDP crystal is morecomplex than that in bulk damage.Under the irradiation laser corresponding to the pulse width of 10 ns and thedamage probability at 0%−50%,surface damage morphology in DKDP crystals mainly contained four typicaldamage morphology:crater with cavity,crater with flat bottom,surface damage crack,and surface ablation.Throughthe comparison and analysis of the imaging of optical microscope and scanning electron microscope,damageprecursors that induced damage craters with bottom cavity and surface cracks were mainly bulk defects,which werethe same as the precursors forming the internal damage points(pinpoints).The precursors that induced damage craterswith flat bottom were relatively complex,which could be the surface contamination,surface cracks,machiningdefects,and shallow surface bulk defects.For surface ablation,it was mainly caused by surface contamination andsurface absorption defects.Surface damage is still one of the important factors limiting the laser damage resistance ofKDPD crystals.

关 键 词：激光诱导表面损伤 DKDP晶体 损伤形貌 材料体缺陷 表面加工缺陷 

分 类 号：TP244[自动化与计算机技术—检测技术与自动化装置]