Long Tianyun, Zhou Cangtao, Wu Sizhong, Ju Libao, Jiang Ke, Bai Ruixue, Huang Taiwu, Zhang Hua, Yu Mingyang, Ruan Shuangchen, He Xiantu
Center for Applied Physics and Technology, HEDPS, and School of Physics, Peking University, Beijing 100871, China.
Center for Advanced Material Diagnostic Technology, and College of Engineering Physics, Shenzhen Technology University, Shenzhen 518118, China.
Phys Rev E. 2021 Feb;103(2-1):023204. doi: 10.1103/PhysRevE.103.023204.
It is shown theoretically and by simulation that a Gaussian laser beam of relativistic intensity interacting with a uniform-thickness plasma slab of azimuthally varying density can acquire orbital angular momentum (OAM). During the interaction, the laser ponderomotive force and the charge-separation force impose a torque on the plasma particles. The affected laser light and plasma ions gain oppositely directed axial OAM, but the plasma electrons remain almost OAM free. High OAM conversion efficiency is achieved due to the strong azimuthal electromagnetic energy flow during the laser phase modulation. The present scheme should provide useful reference for applications requiring relativistic-intense vortex light.
理论分析和模拟结果表明，相对论强度的高斯激光束与密度呈方位角变化的均匀厚度等离子体平板相互作用时可获得轨道角动量（OAM）。在相互作用过程中，激光有质动力和电荷分离力对等离子体粒子施加了一个转矩。受影响的激光和等离子体离子获得方向相反的轴向OAM，但等离子体电子几乎保持无OAM状态。由于激光相位调制过程中强烈的方位角电磁能流，实现了高OAM转换效率。该方案应为需要相对论强涡旋光的应用提供有用的参考。
