# Achieving extreme light intensities using relativistic plasma mirrors

## TL;DR

This paper demonstrates through advanced 3D simulations that relativistic plasma mirrors can be used to focus harmonics to intensities approaching the Schwinger limit, enabling new pathways for extreme light-matter interactions.

## Contribution

It introduces a comprehensive 3D model of harmonic focusing by curved relativistic plasma mirrors and proposes innovative all-optical methods to enhance plasma mirror curvature.

## Key findings

- Achieved harmonic focusing intensities between 10^{25} and 10^{26} W/cm^2.
- Validated a general 3D model of plasma mirror harmonic focusing.
- Proposed techniques to increase plasma mirror curvature toward the Schwinger limit.

## Abstract

In this letter, cutting-edge 3D Particle-In-Cell simulations are used to demonstrate that so-called relativistic plasma mirrors irradiated by PetaWatt (PW) lasers and naturally curved by laser radiation pressure can be used to tightly focus Doppler-generated harmonics to extreme intensities between $10^{25}-10^{26}W.cm^{-2}$. Those simulations are then employed to develop and validate a general 3D model of harmonic focusing by a curved relativistic plasma mirror. Finally, the insight gained from this model is used to propose novel all-optical techniques that would further increase the plasma mirror curvature with the ultimate goal of approaching the Schwinger limit.