Time-resolved measurements of electron density and plasma diameter of 1 kHz femtosecond laser filament in air  

作　　者：Hengyi Zheng Fukang Yin Tie-Jun Wang Yaoxiang Liu Yingxia Wei Bin Zhu Kainan Zhou Yuxin Leng 郑恒毅;尹富康;王铁军;刘尧香;魏迎霞;朱斌;周凯南;冷雨欣(State Key Laboratory of High Field Laser Physics,Shanghai Institute of Optics and Fine Mechanics and CAS Center for Excellence in Ultra-intense Laser Science,Chinese Academy of Sciences,Shanghai 201800,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;Laser Fusion Research Center and Science&Technology on Plasma Physics Laboratory,China Academy of Engineering Physics,Mianyang 621999,China)

机构地区：[1]State Key Laboratory of High Field Laser Physics,Shanghai Institute of Optics and Fine Mechanics and CAS Center for Excellence in Ultra-intense Laser Science,Chinese Academy of Sciences,Shanghai 201800,China [2]Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China [3]Laser Fusion Research Center and Science&Technology on Plasma Physics Laboratory,China Academy of Engineering Physics,Mianyang 621999,China

出　　处：《Chinese Optics Letters》2022年第9期73-78,共6页中国光学快报（英文版）

基　　金：supported in part by NSAF(No.U2130123);International Partnership Program of Chinese Academy of Sciences(Nos.181231KYSB20200033 and 181231KYSB20200040);Shanghai Science and Technology Program(No.21511105000)。

摘　　要：The temporal evolutions of electron density and plasma diameter of 1 kHz femtosecond laser filament in air are experimentally investigated by utilizing a pump-probe longitudinal diffraction method.A model based on scalar diffraction theory is proposed to extract the spatial phase shift of the probe pulse from the diffraction patterns by the laser air plasma channel.The hydrodynamic effect on plasma evolution at 1 kHz filament is included and analyzed.The measured initial peak electron density of~10^(18)cm^(-3) in our experimental conditions decays rapidly by nearly two orders of magnitude within200 ps.Moreover,the plasma channel size rises from 90μm to 120μm as the delay time increases.The experimental observation is in agreement with numerical simulation results by solving the rate equations of the charged particles.

关 键 词：femtosecond laser filamentation electron density DIFFRACTION 

分 类 号：TN249[电子电信—物理电子学] O53[理学—等离子体物理]