Nonlinear dynamics of laser-generated ion-plasma gratings: a unified description

TL;DR

This paper models the nonlinear dynamics of laser-generated plasma gratings, analyzing fluid and kinetic effects to understand their formation, evolution, and collapse under high-intensity conditions.

Contribution

It introduces a unified model explaining plasma grating behavior, identifying key regimes of ion dynamics and criteria for grating saturation and lifetime.

Findings

Electron compression influences grating stability.

Three regimes of ion behavior identified: reflecting, partially passing, crossing.

Criteria for grating lifetime and effects of ion temperature provided.

Abstract

Laser-generated plasma gratings are dynamic optical elements for the manipulation of coherent light at high intensities, beyond the damage threshold of solid-stated based materials. Their formation, evolution and final collapse require a detailed understanding. In this paper, we present a model to explain the nonlinear dynamics of high amplitude plasma gratings in the spatially periodic ponderomotive potential generated by two identical counter-propagating lasers. Both, fluid and kinetic aspects of the grating dynamics are analyzed. It is shown that the adiabatic electron compression plays a crucial role as the electron pressure may reflect the ions from the grating and induce the grating to break in an X-type manner. A single parameter is found to determine the behaviour of the grating and distinguish three fundamentally different regimes for the ion dynamics: completely reflecting, partially reflecting/partially passing, and crossing. Criteria for saturation and life-time of the grating as well as the effect of finite ion temperature are presented.