Coulomb effects on time-trajectory-resolved high-order harmonic generation

Abstract We studied the effects of Coulomb potential on high-order harmonic generation (HHG) numerically and analytically. focus influence emission times HHG associated with specific electron trajectories. By using a numerical procedure based solution time-dependent Schrödinger equation (TDSE) in three dimensions, we extract both for long short compare TDSE predictions those Coulomb-modified model arising from strong-field approximation (SFA). show that effect induces earlier than predicted by general SFA without considering potential. In particular, this influences trajectories differently is more remarkable low-energy harmonics high ones. It also changes amplitudes validate our discussions diverse laser parameters forms Our results strongly support four-step HHG.