Study On Electron Correlation And Manipulation In Double Ionization Process Driven By Two-color Laser Field

Electron correlation is a universal phenomenon in the microscopic world.A simple model of electron correlation is provided for the non-sequential double ionization process of atoms or molecules in the intense laser field,which provides a simple and direct way for the study of electron correlation,and becomes one of the hot spots in the research of intense laser physics.In this paper,the classical Monte Carlo method based on Newton equation is used to study the non-sequential double ionization process of atoms or molecules in a strong laser field.A scheme of controlling the electron collision in the double ionization process by using the two-color field is proposed,and some innovative research results are obtained.The main contents of this thesis are as follows:(1)The double ionization process of Ar atom in the two-color linear polarized laser field is studied.it is found that the intensity and pulse delay of laser field have significant influence on the electron collision,a scheme of controlling the electron collision by using the two-color linear polarized field is proposed,and the optimal laser parameters are determined.This study provides a reference for the effective regulation of electron micro motion.(2)The double ionization process of Ar atom in a two-color circular polarized laser field is studied.It is proposed that the electron collision can be controlled in the time scale of sub-femtosecond by selecting the intensity and frequency of the laser field.It is found that a single electron collision can be obtained by selecting the appropriate laser intensity,and the electron collision time can be controlled within 0.2 period in the two-color laser field with the combination of the fundamental and second harmonic,and within 0.1 period in the two-color laser field with the combination of the fundamental and third harmonic,reaching the femtosecond level.(3)The double ionization process of oxygen molecules in the two-color circular polarized field is studied.According to the valence electron distribution characteristics of oxygen molecules,a scheme is proposed to increase the probability of electronnuclear collision by using combined field of the fundamental frequency and tripled frequency.It is found that the scheme can increase the double ionization rate of oxygen molecules by three orders of magnitude at a lower laser intensity,which is very beneficial to observe the electron correlation effect in the process of double ionization of oxygen molecules.