吴金明 1,2,4赵元安 2,4,5,*汪琳 1,**彭小聪 2,3,4[ ... ]邵建达 2,4,***
1 上海大学材料科学与工程学院, 上海 200444
2 中国科学院上海光学精密机械研究所薄膜光学实验室, 上海 201800
3 中国科学院大学材料与光电研究中心, 北京 100049
4 中国科学院强激光材料重点实验室, 上海 201800
5 中国科学院长春光学精密机械与物理研究所应用光学国家重点实验室, 吉林 长春 130033
6 中国工程物理研究院上海激光等离子体研究所, 上海 201800
为了研究DKDP晶体在惯性约束核聚变(ICF)装置应用中的多波长激光诱导损伤特性,建立了1064 nm激光和355 nm激光同时辐照DKDP晶体的损伤测试装置,分析了不同激光能量密度组合下的损伤针点形貌、密度、尺寸和损伤概率。结果表明,当355 nm激光以R-on-1方式辐照样品,并加入不同能量密度的1064 nm激光时,随着1064 nm激光能量密度的升高,测试样品的抗激光损伤性能得到改善,损伤针点形貌逐渐与1064 nm激光单独作用时的损伤形貌类似,损伤针点密度减小,损伤针点尺寸增大,整体上表现出耦合预处理效应。
激光光学 晶体 预处理效应 多波长激光 损伤缺陷 
Author Affiliations
Abstract
1 Laboratory of Thin Film Optics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
3 Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
A time-resolved high-power laser photometer, which measures the real-time variations of transmission, internal reflection, and scattering simultaneously with picosecond time resolution, was developed to investigate the material response sequence during high-power nanosecond laser irradiation in thick fused silica. It was found that the transient transmission decreased sharply, accompanied by an increase in internal reflection at the rising edge of the laser pulse. The transient transmission recovered, while laser damage did not occur, but it did not recover if the scattering increased, indicating the occurrence of laser damage. The reason for the sharp decrease of transmission and the relationship between the transmission drop and laser damage were discussed.
160.4760 Optical properties 140.3330 Laser damage 160.3380 Laser materials Chinese Optics Letters
2019, 17(5): 051601
Author Affiliations
Abstract
1 Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
3 State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
4 National Engineering Laboratory for Modern Materials Surface Engineering Technology, Guangdong Institute of New Materials, Guangzhou 510650, China
Laser-induced modification at 355 nm of deuterated potassium dihydrogen phosphate (DKDP) crystals following exposure to nanosecond (ns) and sub-ns laser irradiation is investigated in order to probe the absorption mechanism in damage initiation. Laser damage resistance is greatly improved by sub-ns laser conditioning, whereas only a little improvement occurred after ns laser conditioning at the same laser fluence. Moreover, scattering and transmittance variations after the two types of laser conditioning indicate similar reduction of linear absorption. However, by contrast, large differences on nonlinear absorption modification are discovered using Z-scan measurement. This characteristic absorption modification by laser irradiation provides evidence that a nonlinear absorption mechanism plays a key role in damage initiation at 355 nm.
160.4670 Optical materials 190.4180 Multiphoton processes Chinese Optics Letters
2018, 16(5): 051601
1 中国科学院 上海光学精密机械研究所 中国科学院强激光材料重点实验室，上海 201800
2 中国科学院大学，北京 100049
针对晶体表面的损伤特性，采用小光斑扫描激光预处理技术预辐照DKDP晶体元件，并采用表面损伤自动探测系统实时分析每个脉冲辐照后晶体表面的损伤情况，比较预处理和未预处理区域的损伤点密度确定表面预处理效果，并进一步模拟分析表面各类缺陷在纳秒强激光辐照下的动态过程，解释激光预处理对精抛表面提升作用的微观机制并分析它对粗抛表面提升不明显的原因。实验结果表明，激光预处理技术对粗抛表面的提升作用并不明显，但是可以大幅度抑制精抛表面的损伤点密度。在本文的实验条件下，晶体表面的抗激光损伤能力可以提升约60%。比较体材料和精抛表面的预处理效果发现: 当体材料的抗破坏能力通过预处理提升后，精抛表面的抗激光损伤能力也会提升，由此可见精抛表面的激光预处理效果与体材料性能相关。
激光损伤 激光预处理 损伤阈值 预处理效果 氘化磷酸二氢钾(DKDP) laser damage laser conditioning damage threshold laser conditioning effects dopted deuterium KDP (DKDP)
