激光尾波场中光子加速研究

在SILEX-Ⅰ激光装置上，测量了超短超强激光脉冲与稀薄等离子体相互作用之后的透射谱. 实验中发现，激光尾波场产生的密度扰动导致等离子体折射率随时间空间不断变化，导致光子的加速/减速. 透射谱上主要表现为激光频率谱峰的劈裂和随密度变化的展宽，没有发现与前向受激拉曼散射或自调制不稳定性相联系的边频波. 同时，利用LPIC++无碰撞粒子模拟程序模拟了超短超强激光与稀薄等离子体相互作用后的透射谱，模拟结果也发现了明显的光子加速过程. 关键词： 超短超强激光脉冲 透射谱 光子加速/减速

Photon acceleration in the laser wakefield

On the SILEX-Ⅰlaser facility, we measured the transmission spectra after ultrashort and ultraintense laser pulse interaction with tenuous plasma. Due to the existence of the wakefield, the time-dependent refractive index of the plasma can accelerate or decelerate photons of laser pulse when the laser pulse propagates in the plasma. Its main features are the spliting of the fundamental frequency and its evident broadening in the laser transmission spectra.The side_band wave which is often associated with Raman and Self modulation were not observed in our experiments. Utilizing the LPIC++ code, we also simulated the transmission spectrum after the ultrashort_ultrahigh intensity laser pulse interacts with the tenuous plasma. The simulation results are in good agreement with the experiment results.