各阶克尔非线性折射率对强激光大气传输的影响  

Effects of Kerr nonlinear refractive index on propagation of femtosecond laser pulse in atmosphere

作　　者：马存良[1] 王乐[1] 林文斌[1] 

机构地区：[1]西南交通大学物理科学与技术学院,成都610031

出　　处：《强激光与粒子束》2015年第4期36-40,共5页High Power Laser and Particle Beams

基　　金：高等学校博士学科点专项科研基金项目(20110184110016);中央高校基本科研业务费专项资金项目(2682014ZT32);2015年西南交通大学博士研究生创新基金项目

摘　　要：用数值方法研究了各阶克尔非线性折射系数对强激光传输的影响,结果显示第7阶克尔非线性系数和第9阶克尔非线性系数协同影响激光传输,当第7阶克尔效应起作用时,忽略第9阶克尔效应的作用会导致光强随传输距离震荡剧烈,传输非常不稳定。要得到稳定传输需要第7阶克尔非线性系数和第9阶克尔非线性系数同时起作用或同时不起作用。在自聚焦阶段第3阶非线性折射率对折射率改变起主要作用,在稳定光丝传输阶段第7阶克尔非线性系数,第9阶克尔非线性系数起主要作用。第5阶克尔系数在整个传输过程中对折射率的改变一直比较小。The effects of the nonlinear refraction indexes（n2,n4,n6,n8）on the propagation of the femtosecond high-intensity laser pulse are studied.We consider three models.The first model includes n2,n4,n6,and n8.The second one only includes n2 and n4.The third model includes n2,n4,and n6.Numerical simulations show that the third model cannot properly describe the propagation of the ultra-short high intensity laser pulse,and the index n2 is the most important focusing mechanism at the beginning of the propagation,and n8 and n6are the most important indexes in the stable propagation stage,and the pulse’s radius in the first model is almost the same as that in the second model,so does the number of filamentations splitted in the temporal direction.This work is useful in understanding the mechanism of the femtosecond laser pulse propagation in air.

关 键 词：飞秒激光脉冲 激光传输 光丝 高阶克尔效应 

分 类 号：O436.1[机械工程—光学工程]