Wavebreaking-associated transmitted emission of attosecond extreme-ultraviolet pulses from laser-driven overdense plasmas

TL;DR

This paper introduces a novel mechanism for generating attosecond extreme-ultraviolet pulses from laser-driven overdense plasmas, highlighting the role of plasma-density oscillations post-wavebreaking.

Contribution

It reveals a new XUV emission mechanism involving plasma-density oscillations and their coupling with transverse fields in overdense plasmas.

Findings

XUV emission is mainly due to plasma-density oscillations after wavebreaking.

The emitted frequencies are centered around the local plasma frequency.

The mechanism offers new insights into laser-plasma interaction dynamics.

Abstract

We present a new mechanism of attosecond extreme-ultraviolet (XUV) pulses generation from a relativistic laser-driven overdense plasma surfaces in the wavebreaking regime. Through particle-in-cell simulations and analysis, we demonstrate that the observed ultrashort XUV emission for the parameters we considered is predominantly due to a strong plasma-density oscillation subsequent to wavebreaking. The coupling of the strong density variation and the transverse fields in the front surface layer gives rise to the transmitted emission with frequencies mainly around the local plasma frequency. This mechanism provides new insights into the scenarios of XUV generation from solid surfaces and the dynamics of laser-plasma interactions.