Efficient Generation of Tunable Magnetic and Optical Vortices Using Plasmas

TL;DR

This paper demonstrates a theoretical and simulation-based method for efficiently generating tunable magnetic and optical vortices in plasma using relativistic ionization fronts and Laguerre-Gaussian lasers, with controllable topologies and spectral properties.

Contribution

It introduces a novel plasma-based approach for creating high-strength magnetic and optical vortices with tunable features by manipulating laser OAM and plasma parameters.

Findings

Generation of multi-megagauss magnetic vortices.

Frequency upshift of optical vortices over a wide spectral range.

Control of vortex topologies via laser OAM and plasma density.

Abstract

Plasma is an attractive medium for generating strong microscopic magnetic structures and tunable electromagnetic radiation with predictable topologies due to its extraordinary ability to sustain and manipulate high currents and strong fields. Here, using theory and simulations, we show efficient generation of multi-megagauss magnetic and tunable optical vortices when a sharp relativistic ionization front (IF) passes through a relatively long-wavelength Laguerre-Gaussian (LG) laser pulse with orbital angular momentum (OAM). The optical vortex is frequency upshifted within a wide spectral range simply by changing the plasma density and compressed in duration. The topological charges of both vortices can be manipulated by controlling the OAM mode of the incident LG laser and/or by controlling the topology and density of the IF. For relatively high (low) plasma densities, most energy of the incident LG laser pulse is converted to the magnetic (optical) vortex.