物理学报2016，Vol.65Issue(3)：033201-1-033201-6,6.DOI:10.7498/aps.65.033201
势函数对强激光辐照下原子高次谐波辐射的影响∗
Influence of atomic p otential on the generation of high harmonic generation from the atoms irradiated by mid-infrared laser pulses
摘要
Abstract
By numerically solving the time dependent Schrodinger equation, the harmonic spectra generated from the atoms are obtained. The atomic potentials are modeled by a short-range potential and a long-range soft Coulomb potential, respectively. It is found that using the same laser parameters, the intensity of harmonic spectrum from the short-range atom is lower than the one from the long-range atom. However, in a high energy (near the cutoff) region of harmonic spectra, their conversion efficiencies are almost the same. The differences in emission intensity among harmonic spectra decrease as the harmonic energy increases. We calculate the time dependent probabilities of the ground state and ionization. It is found that the ionization probability of the long-range potential is larger than that of the short-range potential. There is no large difference in ground probability between the potentials of two models. The high harmonic generation is a stimulated process, and its intensity is proportional to the product between the amplitude for ground state and the amplitude of the continuum state. Thus the product of the long-range atom is larger than that of the short-range atom, and the emission spectrum presents a similar character. In order to analyze the mechanism of the intensity difference between two models, we perform a time-frequency analysis of the harmonic emission spectrum. The analysis is selected of the wavelet of the time dependent dipole moment. From the emission profile of the harmonic analysis, we find that the harmonic generated from long orbit plays a dominant role for the short-range atom. The amplitudes of electric field are large for the long orbit harmonic emission, thus the ionization mechanism of the atom is the tunnel ionization. For the short orbit, the instant field for the ionization is weak. Thus the short orbit plays a small role in the harmonic emission from the short-range atom. Using this feature of the short-range atom, we generate an isolated attosecond pulse. The short model atom is widely used to study the ionization of the plasma. Thus this work will contribute to the research on the high-order harmonic generation from the plasma.关键词
高次谐波辐射/阿秒脉冲/短程势Key words
high harmonic generation/attosecond pulse/short-range potential引用本文复制引用
刘艳,贾成,郭福明,杨玉军..势函数对强激光辐照下原子高次谐波辐射的影响∗[J].物理学报,2016,65(3):033201-1-033201-6,6.基金项目
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:11274141,11304116,11534004)和吉林省科学基金(批准号20140101168JC)资助的课题.* Project supported by the National Basic Research Program of China (Grant No.2013CB922200), the National Natural Science Foundation of China (Grants Nos.11274141,11304116,11534004), and the Jilin Provincial Research Foundation for Basic Research, China (Grant No.20140101168JC) （批准号:2013CB922200）
