激光场中原子阈上电离的强场近似方法研究  

Study on the strong field approximation method for above threshold ionization of atom in laser field

作　　者：仝小刚[1] 薛玉峰[1] 张治国 杨淑萍 TONG Xiao-Gang;XUE Yu-Feng;ZHANG Zhi-Guo;YANG Shu-Ping(School of Mechanical and Electrical Engineering,Longnan Teachers College,Longnan 742500,China;School of Mathematics and Computational Science,Shaanxi University of Technology,Hanzhong 723000,China)

机构地区：[1]陇南师范高等专科学校机电工程学院,陇南742500 [2]陕西理工大学数学与计算机科学学院,汉中723000

出　　处：《原子与分子物理学报》2025年第2期111-116,共6页Journal of Atomic and Molecular Physics

基　　金：甘肃省高等学校教师创新基金项目(2023B-417,2023B-415)。

摘　　要：强激光与原子相互作用的基本现象是原子的电离,其中阈上电离是一种非常重要的强场电离现象,许多方法被用于研究激光场中原子的阈上电离性质,其中强场近似方法是十分重要的理论方法之一.本文利用时间演化算符及鞍点近似论述了激光场中单原子阈上电离行为的二级强场近似理论,其中一阶近似项给出低能电子的直接电离振幅,二阶近似项描述电子与母离子的重散射过程,表示高能光电子的电离振幅.文章给出了强场近似理论下线性极化的激光场中光电子能谱和电离概率,为应用强场近似方法模拟研究激光场中单原子的动力学行为提供了一定的理论参考和依据.The basic phenomenon of the interaction between intense laser and atom is ionization of atom,among which the above-threshold ionization is a very important phenomenon.Many methods have been used to study the properties of above-threshold ionization of atom in laser field,and the strong field approximation method is one of the very important theoretical methods.In this paper,the second order strong field approximation theory under perturbation theory is derived by using the time evolution operator and saddle point approximation method,the first order approximation term gives the direct ionization amplitude of low energy electron,the second order approximation term describes the rescattering process of electron and parention,and represents the ionization amplitude of high energy photoelectron.The photoelectron spectra and ionization probability of single atom in linearly polarized laser field are given,which provides a theoretical reference and basis for the simulation and study of the kinetic behavior of atoms in laser field under the strong field approximation theory.

关 键 词：阈上电离 强场近似 Schr9dinger方程 时间演化算符 鞍点近似 

分 类 号：O437[机械工程—光学工程]