Multiphoton ionization and high-order harmonic generation of He, Ne, and Ar atoms in intense pulsed laser fields: Self-interaction-free time-dependent density-functional theoretical approach

Abstract

The study of the multiphoton ionization and HHG processes of He, Ne, and Ar atoms in intense pulsed laser fields. All the valence electrons are treated explicitly and the electron correlation is included. The instructive and qualitatively different behavior for different atom and different laser intensity. The detailed analysis of the contributions from the individual valence subshell was presented. Three three main factors are identified for accounting the observed phenomena, namely, the relative binding energy and the orientation of the electron density of individual valence electron orbital, and the multiphoton resonant excitation effect.