超短强激光脉冲在等离子体隧道中传输的理论与数值模拟研究

研究了超短强激光脉冲在非扰动抛物型部分电离的预等离子体隧道中的传输特性.从Maxwell方程出发得到了两个包含衍射、三阶强度非线性、等离子体散焦、等离子体隧道聚焦以及相对论自聚焦等效应在内的激光场演化方程，即折射率方程和哈密顿-雅可比方程.在此基础 上得到了激光在等离子体隧道中传输的包络方程以及光斑半径与传输距离、隧道宽度等初始 参量的关系. 关键词： 等离子体隧道聚焦 相对论自聚焦 势阱

Theoretical and numerical investigation for propagation of ultrashort intense l aser pulse in plasma channel

Characteristics of propagation of ultrashort intense laser pulses in a partially stripped pre-formed plasma channel, assumed to be parabolic and unperturbed, are discussed. From Maxwell equations the refractive index equation and Hamilton-Jacobi equation, which describe the evolution of the electric field, are derived including the effects of the diffraction, the third-order intensity-dependent nonlinearity, plasma defocusing, the self-focusing of the plasma channel, and t he relativistic self-focusing. The envelope equation of laser propagating in the plasma channel, and the general expression relating the laser spot size with th e propagation distance and the width of the plasma channel etc., are derived bas ed on the Hamilton-Jacobi equation and the refractive index equation.