The propagation of a superintense laser pulse in an underdense, inhomogeneous plasma has been studied numerically by two-dimensional particle-in-cell simulations on a time scale extending up to several picoseconds. The effects of the ion dynamics following the charge-displacement self-channeling of the laser pulse have been addressed. Radial ion acceleration leads to the 'breaking' of the plasma channel walls, causing an inversion of the radial space-charge field and the filamentation of the laser pulse. At later times a number of long-lived, quasi-periodic field structures are observed and their dynamics is characterized with high resolution. Inside the plasma channel, a pattern of electric and magnetic fields resembling both soliton- and vortex-like structures is observed.
超强激光脉冲在欠稠密非均匀等离子体中的传播已通过二维粒子模拟在长达数皮秒的时间尺度上进行了数值研究。研究了电荷位移自通道化激光脉冲之后离子动力学的影响。径向离子加速导致等离子体通道壁的“破裂”，引起径向空间电荷场的反转以及激光脉冲的成丝。在较晚时刻，观察到多个长寿命、准周期的场结构，并对其动力学进行了高分辨率表征。在等离子体通道内部，观察到兼具孤子状和涡旋状特征的电场与磁场分布模式。