Author Affiliations
Abstract
1 State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-Intense Laser Science, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
We present a velocity-gauge model for the generation of even-order high harmonics, and reveal that the even-order harmonics originate from the multiple-step transitions among the energy bands in momentum space, while the odd-order harmonics are mainly from direct transitions. The lower valence band is found vital for the generation of even harmonics. Relative intensity of even-order harmonics versus the odd orders is calculated and shows a growing trend as the laser field amplitude increases.
solid high-harmonic generation inversion asymmetry even-order harmonics Chinese Optics Letters
2021, 19(4): 043201
1 常熟理工学院 物理与电子工程学院，江苏 常熟 215500
2 中国科学院上海光学精密机械研究所 强场激光物理国家重点实验室，上海 201800
应用不对称性参量对周期量级强激光脉冲下原子电离分布的反演不对称性进行了定量分析.采用非微扰的散射理论解析方法和三个激光模式模拟超短脉冲，研究不对称性参量随激光强度、包络位相和脉冲宽度的变化.计算表明,这种不对称性是随着波包的绝对位相以正弦形式变化而变化，其最大不对称程度依赖于脉冲强度和脉冲宽度.随着激光强度的提高，不对称性参量是先降低到最小值然后增加.对脉冲宽度相对长、有几个周期量级的高强度激光，其不对称性具有显著的特点.因此，提高脉冲强度有助于对包络绝对位相变化的观察.
反演不对称 周期量级激光脉冲 光电子角分布 包络位相 Inversion asymmetry Few-cycle laser pulse Photoelectron angular distribution Carrier-envelope phase
