Impact of interference between two infrared pulses driving high harmonic generation

TL;DR

This paper explores how interference between two infrared pulses affects high harmonic generation, using experimental and theoretical methods to improve understanding of strong-field nonlinear responses in XUV interferometry.

Contribution

It provides a combined experimental and theoretical analysis of pulse interference effects on high harmonic generation, emphasizing the temporal overlap regime and employing phase-modulation interferometry.

Findings

Interference dynamics are well described by Lewenstein's non-perturbative model.

Phase-modulation interferometry enhances sensitivity in mapping nonlinear responses.

Temporal overlap significantly influences high harmonic generation behavior.

Abstract

Extreme ultraviolet (XUV) interferometry is technically challenging to implement. One approach to generating interference between two XUV pulses relies on driving high-harmonic generation in a gas jet with two collinearly overlapping infrared laser pulses. We investigate this scheme through a combined experimental and theoretical study, with particular emphasis on the regime of temporal overlap between the driving pulses. A special phase-modulation interferometry technique is implemented to increase the sensitivity for the comprehensive mapping of the strong-field induced high-order nonlinear response. We find that the dynamics arising from the interference of the two electric fields can be adequately described by the non-perturbative model developed by Lewenstein and co-workers.