原子激发态在高频强激光作用下的光电离研究  

Investigation of photoionization of excited atom irradiated by the high-frequency intense laser

作　　者：田原野[1] 郭福明[1] 曾思良[2,3] 杨玉军[1] 

机构地区：[1]吉林大学原子与分子物理研究所,长春130012 [2]北京应用物理与计算数学研究所,计算物理重点实验室,北京100088 [3]北京应用物理与计算数学研究所,高能量密度物性数据中心,北京100088

出　　处：《物理学报》2013年第11期209-215,共7页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(批准号:2013CB922200);国家自然科学基金(批准号:11274141;11034003;11274001);中国工程物理研究院科学技术发展基金(批准号:2011B0102026)资助的课题~~

摘　　要：本文通过数值求解动量空间的三维含时薛定谔方程,研究了原子高激发态在高频激光脉冲作用下,在电离阈值附近的光电子能谱和两维动量角分布.研究结果表明:在该能量范围内,单光子电离过程的贡献是最主要的.体系初态的主量子数可以由光电子能谱峰值的位置来确定;体系初态的角量子数可以通过光电子的两维动量角度分布确定.在比较宽泛的参数范围内,这一规律不随入射激光的强度和脉冲时间宽度的改变而改变,因此原则上可以利用它对原子的初态进行识别.此外,还研究了体系的初态为相干叠加态,光电子动量谱随着叠加态相对相位的变化规律.Solving numerically the time-dependent Schr/Sdinger equation in three-dimensional momentum space, we have investigated the energy spectroscopy and two-dimensional momentum angular distribution near the ionization threshold of the photoelectron generated from excited atom under the action of high-frequency laser pulse. The results show that the ionized process is mainly the single-photon ionization in this energy range. The principal quantum number of the initial state can be determined by the position of the first peak in photoelectron spectrum; its angular quantum number of the initial state can be determined by the angular distribution of the two- dimensional momentum of the photoelectron. This law does not change with the variation of the intensity and pulse duration of the incident laser pulse within a relatively broad range of these parameters. In principle, we can utilize these spectra to identify the initial state of the atoms. In addition, the photoelectron momentum spectrum of superposition state is investigated for different relative phase of the state.

关 键 词：阈上电离 激发态 高频激光脉冲 两维动量角度分布 

分 类 号：O562.1[理学—原子与分子物理]