A Relativistic Plasma Polarizer: Impact of Temperature Anisotropy on Relativistic Transparency

TL;DR

This paper shows that temperature anisotropy in relativistically hot plasmas influences their transparency and polarization properties, enabling the plasma to act as a polarizer or waveplate for laser pulses.

Contribution

It reveals how electron distribution anisotropy affects relativistic transparency and polarization control, supported by 3D particle-in-cell simulations.

Findings

Anisotropic electron distributions alter critical density for transparency.

Anisotropy persists despite Weibel instability, affecting laser propagation.

Plasma can function as a polarizer or waveplate for laser pulses.

Abstract

3D particle-in-cell simulations demonstrate that the enhanced transparency of a relativistically hot plasma is sensitive to how the energy is partitioned between different degrees of freedom. For an anisotropic electron distribution, propagation characteristics, like the critical density, will depend on the polarization of the electromagnetic wave. Despite the onset of the Weibel instability in such plasmas, the anisotropy can persist long enough to affect laser propagation. This plasma can then function as a polarizer or a waveplate to dramatically alter the pulse polarization.