Enhanced harmonic generation in relativistic laser plasma interaction

TL;DR

This paper demonstrates enhanced harmonic generation at a relativistic plasma interface due to coupled oscillations at laser and plasma frequencies, supported by simulations showing the underlying physical mechanism.

Contribution

It introduces a novel mechanism for harmonic enhancement involving coupled oscillations at fundamental and plasma frequencies in relativistic laser plasma interactions.

Findings

Harmonic emission results from coupled oscillations at ω_L and ω_P.

Simulation confirms the reflection at a relativistic oscillating mirror.

Enhanced harmonics are due to the combined action of two high velocity oscillations.

Abstract

We report the enhancement of individual harmonics generated at a relativistic ultra-steep plasma vacuum interface. Simulations show the harmonic emission to be due to the coupled action of two high velocity oscillations -- at the fundamental $\omega_L$ and at the plasma frequency $\omega_P$ of the bulk plasma. The synthesis of the enhanced harmonics can be described by the reflection of the incident laser pulse at a relativistic mirror oscillating at $\omega_L$ and $\omega_P$.