Mapping the power-law decay of high-harmonic spectra from laser-plasma interactions
Abstract
Visible or near infra-red light can be manipulated to produce bursts of coherent extreme ultraviolet (XUV) or X-rays via the relativistic high-order harmonic generation process when a laser irradiates a solid plasma target. The intensity of the spectral components of the reflected signal decays with increase of harmonic order and the efficiency of this non-linear process largely hinges on how prompt this decay is. This is governed by the conditions of the laser-plasma interaction for which various models have been proposed. At relativistic intensities, a spectrum exhibiting a power-law decay with an exponent of 8/3 or 4/3 is often stated. Here, we analyse the dependence of this exponent on interaction parameters including the angle of incidence, the carrier envelope phase, intensity of the laser and the pre-plasma length, and discuss opportunities for optimization. Our simulations show that, rather than there being one universal exponent, the spectral decay is a continuous function of the laser-plasma interaction parameters.
Keywords
Cite
@article{arxiv.2202.05042,
title = {Mapping the power-law decay of high-harmonic spectra from laser-plasma interactions},
author = {Shikha Bhadoria and Thomas Blackburn and Arkady Gonoskov and Mattias Marklund},
journal= {arXiv preprint arXiv:2202.05042},
year = {2022}
}