Orbital Angular Momentum (OAM) Vertical-Cavity Surface-Emitting Lasers

TL;DR

This paper presents a novel VCSEL-based device that directly generates high-quality OAM beams, advancing optical communication and quantum key distribution technologies.

Contribution

The authors design and fabricate a micro-scale Spiral Phase Plate integrated with a VCSEL to efficiently produce specific OAM modes directly from the laser source.

Findings

High-efficiency OAM beam generation achieved

Beam quality suitable for optical communications

Potential applications in quantum key distribution

Abstract

Harnessing the Orbital Angular Momentum (OAM) of light is an appealing approach to developing photonic technologies for future applications in optical communications and high- dimensional Quantum Key Distributions (QKD). An outstanding challenge to the widespread uptake of the OAM resource is its efficient generation. We design a new device which can directly emit an OAM-carrying light beam. By fabricating micro-scale Spiral Phase Plates (SPPs) within the aperture of a Vertical-Cavity Surface-Emitting Laser (VCSELs), the linearly polarized Gaussian beam emitted by the VCSEL is converted into a beam carrying specific OAM modes and their superposition states with high efficiency and high beam quality. The innovative OAM emitter opens a new horizon in the field of OAM-based optical and quantum communications, especially for short reach data interconnects and Quantum Key Distribution (QKD).