椭圆偏振激光在等离子体中的调制不稳定性  

Modulation instability of an elliptically polarized laser pulse in plasma

作　　者：陈华英[1,2] 刘三秋[1,2] 李晓卿[3] 

机构地区：[1]南昌大学材料学院,南昌330031 [2]南昌大学理学院,南昌330031 [3]南京师范大学物理系,南京210097

出　　处：《激光技术》2009年第1期77-79,共3页Laser Technology

基　　金：新世纪优秀人才支持计划资助项目(NCET-05-0575);江西省跨世纪学术和技术带头人培养计划资助项目(040010);江西省科技攻关计划资助项目(20061B0402100)

摘　　要：为了研究椭圆偏振激光在等离子体中的调制不稳定性,采用洛伦兹技巧推导出椭圆偏振激光在等离子体中的非线性色散关系,基于横波所满足的非线性控制方程,分析了有限振幅的扰动态引起的调制不稳定性,得到了调制不稳定的时间增长率与扰动态波数之间的函数关系,并对等离子体中不同区域的调制增长率进行了比较。结果表明,激光等离子体的临界面附近的调制不稳定性的时间增长率较激光等离子体中其余位置处更为显著。The nonlinear dispersion relation of an elliptically polarized laser pulse in plasmas was derived by means of Lorentz technique. The modulation instability with finite amplitude in plasmas was analyzed on the basis of the nonlinear controlling equation for transverse wave. The temporal growth rate as a function of perturbed wave number for laser beam propagating through plasmas was found analytically and the modulation instability growth rates in the different regions of plasmas were compared. It is shown that the temporal growth rate of modulation instability is increased significantly in the corona region near the critical surface in laser-produced plasmas.

关 键 词：激光物理 调制不稳定性 微扰法 非线性色散关系 

分 类 号：O534[理学—等离子体物理]