Electrically Pumped Orbital Angular Momentum (OAM) Laser at Telecom Wavelengths

TL;DR

This paper reports the development of an electrically pumped semiconductor laser that directly emits vortex beams with specific orbital angular momentum at telecom wavelengths, simplifying integration for communication and quantum applications.

Contribution

It introduces a monolithically integrated OAM laser on InGaAsP/InP with a novel fabrication process, eliminating the need for external lasers.

Findings

Successful fabrication of electrically pumped OAM laser

High mode purity of emitted vortex beams

Potential for integration into communication systems

Abstract

Semiconductor lasers capable of generating a vortex beam with a specific orbital angular momentum (OAM) order are highly attractive for applications ranging from nanoparticle manipulation, imaging and microscopy to fibre and quantum communications. In this work, an electrically pumped OAM laser operating at telecom wavelengths is fabricated by monolithically integrating an optical vortex emitter with a distributed feedback (DFB) laser on the same InGaAsP/InP epitaxial wafer. A single-step dry etching process is adopted to complete the OAM emitter, equipped with specially designed top gratings. The vortex beam emitted by the integrated laser is captured, and its OAM mode purity characterized. The electrically pumped OAM laser eliminates the external laser required by silicon- or silicon-on-insulator (SOI)-based OAM emitters, thus demonstrating great potential for applications in communication systems and quantum domain.