Plasma q-plate for generation and manipulation of intense optical vortices

TL;DR

This paper introduces a plasma-based q-plate that converts high-intensity Gaussian beams into optical vortices with high efficiency, enabling applications in high-power laser manipulation and broad frequency ranges.

Contribution

It proposes a novel plasma q-plate design that enables direct conversion of intense laser beams into optical vortices with high efficiency across a wide frequency spectrum.

Findings

High power conversion efficiency demonstrated in simulations

Effective vortex generation from terahertz to optical frequencies

Potential for high-intensity optical vortex applications

Abstract

An optical vortex is a light wave with a twisting wavefront around its propagation axis and null intensity in the beam center. Its unique spatial structure of field lends itself to a broad range of applications, including optical communication, quantum information, superresolution microscopy, and multi-dimensional manipulation of particles. However, accessible intensity of optical vortices have been limited to material ionization threshold. This limitation might be removed by using the plasma medium. Here we propose the design of suitably magnetized plasmas which, functioning as a q-plate, leads to a direct convertion from a high-intensity Gaussian beam into a twisted beam. A circularly polarized laser beam in the plasma accumulates an azimuthal-angle-dependent phase shift and hence forms a twisting wavefront. Our three-dimensional particle-in-cell simulations demonstrate extremely high power conversion efficiency. The plasma q-plate can work in a large range of frequencies spanning from terahertz to the optical domain.