相对论长脉冲激光在非均匀等离子体中的传播特性  

Propagation characteristics of relativistic long pulse laser in inhomogeneous plasma

作　　者：薛具奎[1] 黄茂 张小波 张爱霞 唐荣安[1] XUE Ju-kui;HUANG Mao;ZHANG Xiao-bo;ZHANG Ai-xia;TANG Rong-an(College of Physics and Electronic Engineering,Northwest Normal University,Lanzhou 730070,Gansu,China)

机构地区：[1]西北师范大学物理与电子工程学院,甘肃兰州730070

出　　处：《西北师范大学学报（自然科学版）》2021年第3期44-51,73,共9页Journal of Northwest Normal University(Natural Science)

基　　金：国家自然科学基金资助项目(11865014,11764039)。

摘　　要：通过解析和数值方法研究了相对论长脉冲激光在非均匀等离子体中的传播.首先,得到了激光脉冲在均匀等离子体中传播的解析解,并通过数值模拟进行了验证.结果表明,长脉冲激光在均匀等离子体中传播时,脉冲宽度的变化不影响激光强度空间分布的变化;然而,激光脉冲的强度和电子密度的空间分布可以通过调制等离子体频率来调节.在具有高斯型密度分布的非均匀等离子体中,随着高斯型密度分布振幅的增大,激光脉冲的强度逐渐增强,激光脉冲的横向分布逐渐呈现出尖锐状分布;在具有反高斯型密度分布的非均匀等离子体中,随着反高斯型密度分布振幅的减小,激光脉冲的强度逐渐减小,激光脉冲呈现横向平台状分布.因此,等离子体的非均匀性对长脉冲激光的传播有着重要的影响.The propagation of relativistic long pulse laser in inhomogeneous plasma is study by analytical and numerical methods.An analytical solution of the laser pulse propagating in the homogeneous plasma is obtained and verified by numerical results.It is found that the change of laser pulse width does not affect the laser intensity and spatial distribution when the long pulse laser propagates in homogeneous plasma.However,the spatial distribution of laser pulse intensity and electron density can be adjusted by modulating the plasma frequency.In the inhomogeneous plasma with Gaussian density distribution,the intensity of the laser pulse is enhanced significantly with the increase of the amplitude of the Gaussian density distribution,and the transverse distribution of the laser pulse gradually appears a sharp distribution.In inhomogeneous plasma with inverse Gaussian density distribution,the intensity of laser pulse decreases with the decrease of the amplitude of inverse Gaussian density distribution,and the transverse distribution of laser pulse appears a platform distribution.Therefore,the inhomogeneity of plasma has an important influence on the propagation of long pulse laser.

关 键 词：激光等离子体相互作用 非均匀等离子体 激光脉冲的传播特性 

分 类 号：O53[理学—等离子体物理]