The Theoretical Study On The Magnetic Quantum Numbers Resolved Photoionization Of Hydrogen Atom And Fluorine Anion In Intense Laser Fields

With the development of ultra-intense and ultra-short lasers,one can study ultra-fast dynamics of electrons on the attosecond timescale.In many nonlinear optical processes,ionization is always a hot topic in strong-field physics and attosecond science.In recent years,magnetic quantum number resolved photoionization of hydrogen atom and fluorine anion in strong laser fields attracted a wide attention and many research progresses have been made both experimentally and theoretically.In this thesis,we theoretically investigated orbital-resolved photoionisation process of hydrogen atom and fluorine anion in strong laser fields by numerically solving the three-dimensional time-dependent Schr(?)dinger equation(3D-TDSE).The main contents are as follows:(1)We systematically checked the validity of the time-dependent surface flux(t SURFF)open source code by comparing the photoelectron energy spectra(PES)and two-dimensional photoelectron momentum distributions(2D-PMDs)with those obtained from the projection technique(PT)and the strong field approximation(SFA)theory.Firstly,we solve the 3D-TDSE of atoms in intense laser fields using the split-operator method and compare the PES and 2D-PMDs of hydrogen atom and rare-gas atoms(i.e.,He,Ne,Ar,Kr and Xe)driven by a linearly polarized laser pulse from the t SURFF method with those of the PT.Our results show that the PES and2D-PMDs from these two methods agree very well each other.The advantage of the t SURFF method is that smaller box size and less partial waves can be used and therefore the computational cost is significantly reduced.Secondly,we further examined the validity of the time-dependent surface flux(t SURFF)open source code by comparing with the strong-field approximation theory.We calculated the PES and2D-PMDs of two degenerate 2p_-and 2p_+orbitals in the fluorine anion driven by a circularly polarized laser by using the t SURFF method and the SFA theory and found that simulation results from these two methods agree well with each other.(2)we comparatively investigated the electron rotational asymmetry of the excited hydrogen atom and the fluorine anion in left-handed CPL fields by numerically solving the 3D-TDSE.We found that the corotating electron is more favored to release in single-photon ionization regimes both for the excited hydrogen atom and the fluorine anion.However,ionization preferences of 2p_+and 2p_-in these two systems are completely opposite in multiphoton ionization.These different ionization preferences can be attributed to the important roles played by excited bound states in the excited hydrogen atom which are absent in the fluorine anion.