Dynamic of rescattering-electron wave packets in strong and short-wavelength laser fields:Roles of Coulomb potential and excited states

摘要

We investigate the high-order harmonic generation of atoms and molecules exposed in strong and short-wavelength (shorter than 800 nm) laser fields. Our simulations show that the electronic rescattering trajectorydepends strongly on the property of the Coulomb potential. Using numerical schemes, we identify the importantrole of excited states in the emission times of harmonics from molecules. We propose a model, which considersthe initial position when electrons tunnel out from the potential, to explain the electronic response in intense andrelatively high-frequency laser fields.