微观缺陷对材料损伤阈值的影响分析  

Analysis of laser-induced damage threshold influenced by micro-defects

作　　者：李风雨[1] 刘国栋[2] 杜立峰[1] 罗银川[1] 张蓉竹[1] 

机构地区：[1]四川大学电子信息学院,成都610065 [2]中国工程物理研究院流体物理研究所,四川绵阳621900

出　　处：《强激光与粒子束》2015年第6期113-117,共5页High Power Laser and Particle Beams

基　　金：四川省科技支撑计划资助项目(2012F20046);四川省教育厅创新团队资助项目(13TD0048)

摘　　要：为了研究材料表面高频缺陷对损伤阈值的影响规律,针对典型表面圆锥凸起状表面缺陷建立了三维分析模型,使用有限元算法计算了两种不同波长激光辐照下,表面缺陷周围的电场变化规律。基于激光诱导材料产生损伤的场效应理论,对缺陷存在条件下材料的损伤阈值进行了定量计算。结果表明,缺陷的存在会对电场产生明显的放大效应,这将直接导致损伤阈值的下降;损伤阈值与缺陷高度成反比关系,与入射波长成正比关系;缺陷导致的损伤阈值下降幅度会随脉宽增加先减小后增大,当入射波长分别为351nm和1064nm时,缺陷导致的损伤阈值下降幅度分别在脉宽为1.80ps和15.80ps处最小。In order to study the effect of the defects on damage threshold of the surface, we modeled a classical three-dimen- sion defect which is similar to the circular cone protuberance and calculated the electric field around this kind of defects by finite- difference method. Based on the field effect theory we calculated the damage thresholds of surfaces with different size defects. It can be got that the electric fields were amplified obviously, which directly leads to lower damage thresholds. The damage thresh- old increases as incident wavelength increases and the height of defect decreases. The reduction of damage threshold caused by de fect decreases first and then increases with the pulse increasing. The damage threshold owns a minimum at 1.80 ps and 15.80 ps when the wavelength is respectively 351 nm and 1064 nm.

关 键 词：激光 损伤阈值 电场 表面高频缺陷 圆锥凸起 

分 类 号：TN248[电子电信—物理电子学]