Photoelectron Holography In The Atomic Ionization By Parallel Polarized Two Color Laser Field

The appearance of the first ultrashort intense laser pulse promotes the development of attosecond science and its related fields.When ultrashort intense laser pulse interacts with atoms and molecules,it can produce many highly nonlinear effects,such as high-order over threshold ionization,tunneling ionization,high-order harmonic generation,photoelectron holography and so on.In recent years,the photoelectron holography based on the process of photoelectron re scattering has attracted people's attention.Optoelectronic holography can be used to detect the ultrafast kinetic information of the parent nucleus and photoelectron on the attosecond time scale,so it has been the research hotspot of intense field physics since it was observed experimentally.In the past,people mostly used monochromatic laser field in the research of photoelectron holography.In this paper,we studied the interference of photoelectron holography in parallel polarized two-color laser field in detail.We found that with the change of relative phase,the swing of holographic interference fringe position recorded the difference between the time of photoelectron re scattering and the time of ionization in the two-color laser field,and found that the effect of Coulomb potential on the light in the two-color laser field The movement of electron holographic fringes has an important influence.The research content of this paper is as follows:In this paper,the photoelectron momentum spectrum of Ar atom is measured by cold target recoil ion momentum imaging spectrometer and femtosecond parallel two-color laser field.It is found that the fringe position of photoelectron holographic interference will change with the change of relative p hase.The exact numerical simulation of the time-dependent Schrodinger equation is carried out in theory,and the results are in good agreement with the experimental results.In order to find out the root cause of this phenomenon,the strong field approximation model is used to simulate the calculation.The calculation results show that the movement of photoelectron holographic interference fringes is caused by the difference between the time of photoelectron re scattering and the time of ionization.Furthe r research shows that,unlike the photoelectron holographic fringes in the orthogonal dichroic field,the effect of Coulomb potential has an important influence on the movement of photoelectron holographic fringes in the parallel dichroic laser field,whic h is of great significance for understanding the formation and change process of holographic interference.