Research On The Ionization Time Of Multiple-returning Electron Wave Packet And The Initial Position Of Single Photon Ionized Electron Wave Packet Based On Photoelectron Holography

Tunneling ionization is the basic processes of the interaction between the strong-field laser and matter.The ionized electron wave packet oscillates under the drive of laser pulse,and some electrons return to the parent nucleus and rescatter with it.This process leads to a series of nonlinear phenomena,such as high-order above-threshold ionization,high-order harmonic generation and nonsequential double ionization.After tunneling ionization,the electron wave packets with the same final momentum interfere with each other to form rich interference structures in the photoelectron momentum spectrum.The strong field photoelectron holography is one of the important photoelectron interferences.By studying this structure,the ultrafast dynamics information of electron and parent nuclei can be extracted.In this paper,the photoelectron holographic interference in tunneling ionization are studied and the effects of electron ionization and return time on multiple-returning photoelectron holographic interference are discussed.At the same time,the holographic interference of single photon ionization in attosecond field with the aid of infrared field is studied and the initial position of electron is extracted.The main research contents of this thesis are as following:(1)The multiple-returning photoelectron holographic interference of xenon atoms in the orthogonally polarized two-color fields are studied.By solving the time-dependent Schr(?)dinger equation,it is found that the interference fringes of the first-returning and the second-returning shift periodically with the relative phase of the two-color fields,and the fringes shift depends on the longitudinal momentum.By extracting the phase of the shift at the minimum value,it is revealed that the shift of the first-returning and the second-returning holographic interference fringes have different dependence on the longitudinal momentum.Using the strong field approximation model,it is found that the difference comes from the ionization time and return time of the electron.The time information of the electron in the tunneling ionization process can be measured by analyzing shift of multiple-returning holographic interference fringe with relative phase.In addition,the result clearly indicates that the effect of Coulomb interaction on interference fringes shift of first-returning and the second-returning is negligible.(2)The initial position of the electron wave packet of hydrogen molecule ion in attosecond streaking field is studied.By numerically solving the time-dependent Schr(?)dinger equation,the effects of the pulse duration and frequency of a single attosecond field on the holographic interference structure are studied.In addition,it is found that the holographic interference fringes are shift under different molecular axial orientations.By analyzing the holographic interference fringes,the phase difference between the direct electron and the rescattering electron can be obtained.The difference method is used to extract the initial position information of the electron wave packet under different molecular axial orientations.