利用一维质点网格法（PIC）数值模拟了低密度等离子体薄膜对高强度激光脉冲的整形效应，通过改变薄膜靶的厚度，得到了不同宽度的具有陡峭上升沿的激光脉冲。研究结果表明，激光脉冲的前沿被光压驱动形成的高速运动电子层反射，激光脉冲主要部分在电子层到达靶后表面时发生透射。激光等离子体薄膜相互作用过程中没有形成电子-离子双层结构，电子层到达靶后表面时迅速扩散消失不再反射光脉冲，因此透射的激光脉冲峰值功率衰减较少。

The shaping effects for the intense laser pulse of a low-density plasma foil is investigated by numerical simulation employing a one dimensional particle-in-cell (PIC) code. Laser pulses with steep leading edge of different pulse durations are obtained by changing the thickness of the plasma foil.The results show that a moving-electron-layer (MEL) is generated and driven forward by the radiation pressure, the leading edge is reflected by the MEL and the main part of the pulse is transmitted when the MEL reaches the rear surface of the foil. The single MEL vanishes quickly without double-layer structure, so the peak power of the pulse has no obvious attenuation.