激光与光电子学进展, 2019, 56 (12): 120202, 网络出版: 2019-06-13
氢原子在少周期强激光场中阈上电离的干涉效应 下载: 937次
Interference Effect in Above-Threshold Ionization of Hydrogen Atom by Intense Few-Cycle Laser Fields
原子与分子物理学 阈上电离 周期内/周期间干涉 二维动量谱 光电子能谱 atomic and molecular physics above-threshold ionization intracycle/intercycle interferences two-dimensional momentum spectra photoelectron energy spectra
摘要
利用强场近似结合时间窗函数的方法,计算了氢原子在少周期强激光场中阈上电离的二维动量谱,并与利用Coulomb-Volkov近似结合时间窗函数计算的结果进行了比较。发现在长程库仑势作用下,周期内干涉及周期间干涉的共同作用形成了二维动量谱中的扇形结构条纹。通过求解含时薛定谔方程方法,计算了氢原子在不同脉宽下的二维动量谱,发现二维动量谱中除了周期内干涉和周期间干涉条纹,还出现了一些特殊的条纹结构。研究结果表明,该结构是由再散射电子波包形成的。
Abstract
Using the strong field approximation method combined with the time window function, the two-dimensional (2D) momentum spectra of hydrogen atoms for above-threshold ionization by a few-cycle intense laser field were calculated and compared with the results obtained by the Coulomb-Volkov approximation combined with the time window function. It is found that the fanlike structures in the 2D momentum spectra are formed as a result of the interplay of intracycle and intercycle interferences under the action of a long-range Coulomb potential. In addition, the 2D momentum spectra of hydrogen atoms under different pulse durations were calculated by solving the time-dependent Schr dinger equation and it is found that some special fringe structures appear in the 2D momentum spectra beyond the intracycle and intercycle interference fringes. These structures are formed by the rescattered electron wave packets.
郭志坚, 孙乾. 氢原子在少周期强激光场中阈上电离的干涉效应[J]. 激光与光电子学进展, 2019, 56(12): 120202. Zhijian Guo, Qian Sun. Interference Effect in Above-Threshold Ionization of Hydrogen Atom by Intense Few-Cycle Laser Fields[J]. Laser & Optoelectronics Progress, 2019, 56(12): 120202.