High-order above-threshold ionization in elliptically polarized laser fields: Identifying the recollision time

Abstract

We simulate the two-dimensional high-energy photoelectron momentum distributions (PMDs) for high-order above threshold ionization (HATI) of hydrogen atoms in intense elliptically polarized laser fields by using the strong-field approximation and solving the time-dependent Schr\"odinger equation. It is found that the centers of the left- and right-side circular rescattered ridges in the PMDs due to elastic collision of the returning electron with the parent ion, that locate on the polarization axis for linearly polarized laser field, move slightly below and above the major polarization axis, respectively, for elliptically polarized laser fields. We suggest that, by analyzing the center shift of the measured PMDs for HATI in elliptically polarized fields, one can identify the recollision time.