Classical trajectories in polar-asymmetric laser fields: Synchronous THz and XUV emission

TL;DR

This paper investigates the generation of synchronized XUV and THz emissions in argon plasma driven by two-color femtosecond lasers, revealing correlations linked to electric field asymmetry and classical electron trajectories.

Contribution

It introduces a simple analytical model based on classical trajectories that accurately predicts the observed correlations in asymmetric laser fields.

Findings

Correlations between high-harmonics and THz radiation depend on phase delay.

Classical trajectory model matches experimental results.

Asymmetry degree influences emission characteristics.

Abstract

Synchronous extreme ultraviolet (XUV) and single-cycle terahertz (THz) bursts are generated in argon plasma induced by intense two-color femtosecond laser pulses. Correlations between the intensity of the even and odd high-harmonics and the THz radiation are found by studying the phase-delay between the excitation pulses at 800 and 400 nm as well as the degree of polar asymmetry in the incident electric field. Experiments in both the weak- and strong- polar asymmetric regimes show remarkable agreement with a simple analytical model based on classical electron trajectories in an arbitrary synthetic electric field.