基于单束强激光和固体靶相互作用的瞬态等离子体密度光栅产生研究

Generation of transient plasma density grating induced by interaction between single laser pulse and solid-density plasma

通过1维粒子模拟(PIC)的方法,发现利用单束超短激光与固体密度的等离子体碳靶相互作用可以产生瞬态等离子体密度光栅。研究表明,当选取合适的激光以及等离子体参数,等离子靶后表面的反射激光与入射激光通过干涉形成驻波,然后等离子体在有质动力势和电荷分离场的调制下演化出瞬态等离子体数密度光栅。当波长在40~130 nm之间的紫外飞秒激光束和亚临界密度等离子体相互作用时,瞬态等离子密度光栅的稳定时间可达数十个皮秒,峰值密度最大可达初始数密度二十倍以上。和传统的通过双激光束干涉或者梯度靶形成等离子体光栅的方案相比,该方案只需要单束激光和均匀固体靶相互作用就可以实现等离子体光栅,且具有更高的对比度,在实验上更容易实现。

In 1D particle-in-cell(PIC)simulation,it is found that a plasma grating is produced by the interaction of a single ultra-short laser pulse with a solid-density plasma carbon target.When the appropriate laser and plasma parameters are used,the incident laser and the laser reflected by the rear-surface of the plasma target can form a standing wave,resulting in a ponderomotive force and charge-separation field that can modulate the plasma density and form a plasma density grating.Under this mechanism,we have studied the plasma density gratings generated by the interaction between plasma and ultraviolet laser pulses with wavelengths ranging from 40nm to 130 nm.The results show that,using a single laser pulse and a under-critical plasma target,stable plasma gratings can last more than several tens of picoseconds,with the max peak density greater than twenty times that of the initial density.Compared with traditional generation of plasma gratings with two laser beams or density-gradient plasmas,this scheme with uniform plasma is easier to carry out.