激光预处理提升DKDP晶体加工表面的抗损伤能力  

Improvement of laser damage resistance at surface of DKDP crystal by laser conditioning process

作　　者：罗阳[1,2] 胡国行[1] 赵元安[1] 杨留江 曹珍[1,2] 李大伟[1] 刘晓凤[1] 

机构地区：[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

出　　处：《光学精密工程》2017年第8期1987-1994,共8页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.61405219;No.11304328)

摘　　要：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。In view of damage characteristics of on the laser induced surface damage threshold scan pre-exposure and real-time damage event crystal surface, the effect of laser conditioning process of DKDP crystals was determined by combining raster imaging technique. By simulating dynamic process of different defects exposed to intense nanosecond laser pulse, the mechanisms of the effect of laser con- ditioning process on rough and well polished surfaces were discussed separately. The results show that laser damage density of well polished surface is remarkably decreased by the laser conditioning process while laser damage resistance of the rough polished surface cannot be improved. The laser damage re- sistance is increased by 60% under given experimental conditions. By comparing effects of laser condi-tioning process on the well polished surface to that in the bulk, it indicates that damage resistance on the surface can be improved when laser damage resistance in the bulk is increased by laser conditioning process. Thereby the effect of laser conditioning process on surface damage threshold is related to that of bulk material.

关 键 词：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) 

分 类 号：TN249[电子电信—物理电子学] TN244