激光脉冲初相位调制电子受激辐射后向对称性

Backward symmetry of the excited electron radiation modulated by the initial phase of laser pulse

为了研究线偏振超短超强激光脉冲中高能电子运动和辐射的后向对称性,基于经典非线性Thomson散射的框架,借助数值模拟软件绘制了电子轨迹、空间辐射能量的角分布和空间频率分布直方图。研究发现,当激光脉冲短至只有几个周期时,非线性Thomson散射受激光初始相位的影响十分显著,其能量空间分布和运动轨迹具有很强的相关性,并且相对于驱动激光的初始相位具有“三重对称”的特性。高次谐波频谱的截止可以达到1×10^(6)ω_(0),而频谱峰值的对称性则可为实际激光参数的选择提供可行的思路。研究表明,通过激光脉冲包络相位调制获得理想的非线性Thomson后向散射空间辐射角分布和高次谐波幅度峰值是可行的。

To investigate the motion and radiation backward symmetry of high-energy electrons in linearly polarized ultrashort ultrastrong laser pulses,the electron trajectory,the angular distribution of spatial radiation energy,and the histogram of the spatial frequency distribution is plotted with the aid of numerical simulation software,based on the framework of classical nonlinear Thomson scattering.According to the research,nonlinear Thomson scattering is significantly influenced by the initial phase of the laser when the laser pulse is only a few cycles long.Also,its moving trajectory and spatial energy distribution which have apparent correlations have a"triple-symmetric"property concerning the initial phase of driving laser.The cutoff of the high harmonic spectrum can reach 1×10^(6)ω_(0),and the symmetry of high harmonic amplitude peaks provides a feasible idea of the selection of laser parameters in actual experiments.The study also provides a viable approach to obtain the desired spatial angle distribution of radiation energy and high harmonic amplitude peak of inverse nonlinear Thomson scattering by initial envelop phase modulation of the laser pulse.