激光辐射损伤阈值与激光脉宽相互关系的模拟计算(英文)  

Calculation of Threshold Dependence of Laserinduced Damage upon Pulse Duration

作　　者：马国斌[1] 谭维翰[2] 王占山[3] 

机构地区：[1]中国科学院上海光学精密机械研究所 [2]上海大学物理系 [3]中国科学院长春光学精密机械研究所

出　　处：《光学精密工程》1998年第3期22-27,共6页Optics and Precision Engineering

摘　　要：描述了一个超短脉冲引起的电介质激光损伤的理论模型，这个模型考虑了多光子电离、雪崩电离、电子－离子复合和电子扩散。通过假设激光脉冲为高斯型，数值计算得到了激光脉冲宽度与激光辐射损伤间的依赖关系。对于大于１０ｐｓ的脉冲宽度，数值结果与平方根关系符合很好，对于亚皮秒激光脉冲，通过适当选择损伤的评价标准，我们的模型解释了Ｄｕ等［１０］和Ｓｔｕａｒｔ［１１］等的相对实验结果。A theoretical model is developed to describe the process of laserinduced damage of dielectrics with ultrashort pluses,in which the multiphoton ionization,avalanche ionization,electronion recombination,and the electron diffusion are taken into account.By assuming a Gaussian temporal shape of laser pulse,some numerical results of the threshold dependence on pulse duration are presented.For pulse length longer than 10ps,the numerical results agree well with the squareroot relation.For pulse length of subpicosecond,our model principally explains the opposite experimental results of Du et al.'s (Appl.Phys.Lett.,64,3071(1994)and Stuart el al.'s (Phys.Rev.Lett,74,2248(1995) by properly choosing the criterion of damage.

关 键 词：激光损伤 短激光脉冲 雪崩电离 阈值 模拟计算 

分 类 号：TN241[电子电信—物理电子学]