中文摘要：

理论上研究了两束交叉传播的激光束与等离子体相互作用产生的电子和离子密度调制.用一维粒子模拟程序（particle-in-cell,PIC）研究了两束激光脉冲产生的干涉场激发的等离子体布拉格光栅.研究表明等离子体初始密度、脉冲强度和宽度共同影响等离子体布拉格光栅的演化.光栅的密度峰值可以达到初始等离子体密度的8倍以上,并且可以维持几皮秒的时间.等离子体布拉格光栅可以囚禁由受激拉曼散射形成的电磁孤子,从而形成准稳态的孤子结构,很大程度上降低了形成电磁孤子所要求的激光脉冲强度.

英文摘要：

Solutions of electron and ion density gratings at the linear stage are given.Deep plasma gratings produced by the ponderomotive force of the interference of the two intersecting laser pulses are investigated.Dependence of the plasma grating on the plasma density,duration and intensity of the laser pulses are studied with 1D particle-in-cell（PIC） simulation.It is found that the density of peaks of such gratings can be 8 times the initial plasma density and can last a few picoseconds.We have found stable,long-lifetime electromagnetic solitons by use of these gratings.It is shown that the intensity for the formation of relativistic EM solitons with two crossed-propagating pulses is reduced to a great extent.