空气中飞秒激光脉冲成丝的干涉诊断研究  

Research on Interference Diagnostics of Femtosecond Laser Pulses Filament in Air

作　　者：刘复麟 张兰芝 常峻巍 李东伟 林景全[1] 郝作强[1] L;ZHANG Lanzhi;CHANG Junwei;LI Dongwei;LIN Jingquan;HAO Zuoqiang(School of Science,Changchun University of Science and Technology,Changchun 130022)

机构地区：[1]长春理工大学理学院,长春130022

出　　处：《长春理工大学学报（自然科学版）》2018年第4期1-5,共5页Journal of Changchun University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金(11474039;11774038;11274053);吉林省科技厅项目(20170519018JH);长春理工大学科技创新基金项目(XJJLG-2016-02)

摘　　要：使用马赫-曾德激光干涉方法对空气中的飞秒激光成丝进行了测量分析。首先获得了激光成丝等离子体的阴影图像,通过调节探测光的延迟,获得了激光成丝的电离波前速度。进一步,利用快速傅利叶变换和相位解缠等方法对马赫-曾德干涉图进行了处理,获得了相移分布及电子密度分布,得到了电子密度随延迟时间的变化规律。结果表明,在紧聚焦的条件下,成丝等离子体的电子密度达到了10^(18)cm^(-3)量级并随着延迟的增加而迅速降低。The femtosecond filamention in air is measured and analyzed by Mach-Zehnder femtosecond laser Interferometer. Firstly,the formation of the filament is recorded by time resolved shadowgraph;and the ionization front velocity of the filamentation plasma is obtained. Furthermore,by using algorithms of fast Fourier transform and phase unwrapping,the distribution of phase shift and electron density at difference delay times are obtained. It is found that the electron densities of the femtosecond filaments formed with different focal lens reach the level of 1018 cm-3 followed by a rapid decrease.

关 键 词：飞秒激光成丝 电离波前 等离子体 电子密度 

分 类 号：O437.5[机械工程—光学工程]