Wavelength and intensity dependence of multiple forward scattering at above-threshold ionization in mid-infrared strong laser fields

TL;DR

This study investigates how multiple forward scattering influences Coulomb focusing in mid-infrared laser fields during above-threshold ionization, revealing its dependence on laser intensity and wavelength.

Contribution

It provides new insights into the role of high-order rescattering events and their weak dependence on laser parameters in the classical regime.

Findings

High-order rescattering significantly contributes to Coulomb focusing.

The effective number of rescattering events depends weakly on laser parameters.

Forward scattering's contribution decreases with increasing laser intensity and wavelength.

Abstract

The nonperturbative role of multiple forward scattering for Coulomb focusing in mid-infrared laser fields and its dependence on a laser intensity and wavelength are investigated for low-energy photoelectrons at above-threshold ionization. We show that high-order rescattering events can have comparable contributions to the Coulomb focusing and the effective number of rescattering depends weakly on laser parameters in the classical regime. However, the relative contribution of the forward scattering to the Coulomb focusing and the Coulomb focusing in total decrease with the rise of the laser intensity and wavelength.