Finance

Physics

Laser

Operating system

Vortex

Enhanced Data Rates for GSM Evolution

Angular momentum

Economics

Condensed matter physics

Lasing threshold

Computer science

Spin (aerodynamics)

Mode (computer interface)

Quantum mechanics

Momentum (technical analysis)

Telecommunications

Thermodynamics

Physical Review Letters

Spin-momentum locking is a direct consequence of bulk topological order and provides a basic concept to control a carrier's spin and charge flow for new exotic phenomena in condensed matter physics. However, up to date the research on spin-momentum locking solely focuses on its in-plane transport properties. Here, we report an emerging out-of-plane radiation feature of spin-momentum locking in a non-Hermitian topological photonic system and demonstrate a high performance topological vortex laser based on it. We find that the gain saturation effect lifts the degeneracy of the paired counterpropagating spin-momentum-locked edge modes enabling lasing from a single topological edge mode. The near-field spin and orbital angular momentum of the topological edge mode lasing has a one-to-one far-field radiation correspondence. The methodology of probing the near-field topology feature by far-field lasing emission can be used to study other exotic phenomena. The device can lead to applications in superresolution imaging, optical tweezers, free-space optical sensing, and communication.Received 4 March 2020Accepted 3 June 2020DOI:https://doi.org/10.1103/PhysRevLett.125.013903© 2020 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasOptics & lasersTopological effects in photonic systemsPhysical SystemsSemiconductor lasersTopological materialsNonlinear Dynamics

Spin-Momentum-Locked Edge Mode for Topological Vortex Lasing