周期量级超短激光脉冲在近临界密度等离子体中形成的光孤子

Solitons formed by ultrashort laser pulses propagating in a plasma

利用一维粒子模拟程序 ,观测到周期量级的超短激光脉冲在等离子体中可以以孤子形式传播 .它在一定密度等离子体中以较高的群速度向前传播 ,并在到达等离子体与真空界面时发生反射和透射 .当入射激光脉冲强度增大时 ,非线性调制效应使它产生较大的频率下移 ,致使光孤子传播速度变小 .另外 ,对于同样光强下的几十个周期以上的光脉冲 。

Using one-dimensional particle-in-cell simulations, we observed the formation of solitons which can move with high group velocities when ultrashort laser pulses at a few cycles only propagate in underdense plasma near the critical density. There exist reflection and transmission when the solitons arrive at the plasma-vacuum boundary. When the intensity of initial laser pulses increases, the velocity of the formed solitons decreases. When a laser pulse at a few tens of cycles propagates in such a plasma, a cluster of solitons are left behind, and trapped in the plasma.