Semiclassical analysis of photoelectron interference in a synthesized two-color laser pulse

TL;DR

This study investigates photoelectron interference patterns in strong-field ionization of krypton using a two-color laser pulse, revealing phase-dependent oscillations and interference effects through analytical modeling.

Contribution

It extends RABBITT analysis to the strong-field regime by deriving analytical expressions for phase-dependent oscillations in photoelectron spectra.

Findings

Oscillations of ATI and sideband peaks depend oppositely on the relative phase.

A phase shift of π/4 is observed for interference maxima in the main ATI peak.

Analytical expressions accurately describe the phase-dependent oscillations.

Abstract

We measure the photoelectron energy spectra from strong-field ionization of Kr in a two-color laser pulse consisting of a strong 400-nm field and a weak 800-nm field. The intensities of the main above-threshold ionization (ATI) and sideband peaks in the photoelectron energy spectra oscillate roughly oppositely with respect to the relative phase between the two-color components. We study the photoelectron interferometry in strong-field ATI regime from the view of interference of different electron trajectories in order to extend RABBITT type analysis to the strong-field regime. Based on the strong-field approximation model, we obtain analytical expressions for the oscillations of both ATI and sideband peaks with the relative phase. A phase shift of \pi/4 with respect to the field maximum of the two-color laser pulse is revealed for the interference maximum in the main ATI peak without including the effect of the atomic potential.