Direct Generation of Radially Polarized Vector Vortex Beam with an Exciton-Polariton Laser

TL;DR

This paper demonstrates a novel on-chip polariton laser that directly generates stable, single-mode, radially polarized vector vortex beams using a polarization-selective grating, advancing applications in imaging and communication.

Contribution

It introduces a new method for direct generation of vector vortex beams from a vertical-cavity polariton laser with polarization control integrated into the cavity.

Findings

Achieved low-threshold, stable single-mode lasing with radial polarization.

Demonstrated polarization and phase control via imaging and interferometry.

Enabled scalable, on-chip integration of vector vortex laser beams.

Abstract

Vector vortex beams are a class of optical beams with singularities in their space-variant polarization. Vector vortex beam lasers have applications in many areas including imaging and communication, where vertical-cavity lasers emitting Gaussian beams have been most widely used so far. Generation of vector vortex beams from vertical-cavity lasers has required external control or modulation. Here, by utilizing a polarization-selective subwavelength grating as one of the reflectors in a vertical semiconductor microcavity, we design the spin textures of the polariton mode and demonstrate polariton lasing in a single-mode, radially polarized vector vortex beam. Polarization and phase distributions of the emission are characterized by polarization-resolved imaging and interferometry. This method of vector vortex laser beam generation allows low threshold power, stable single-mode operation, scalability, and on-chip integration, all of which are important for applications in imaging and communication.