Switching of optical vortices in nonlinear annular couplers

TL;DR

This paper introduces an annular waveguide coupler capable of switching the angular momentum of optical vortices in nonlinear media, demonstrating effective control of vortex beams at low power levels.

Contribution

It proposes a novel annular waveguide coupler design for vortex beam switching and analyzes its performance in linear and nonlinear regimes.

Findings

Switching occurs below the collapse threshold.

Inner-ring excitation results in sharper and more efficient switching.

Low power levels prevent azimuthal instability.

Abstract

We suggest an annular waveguide coupler for switching the angular momentum of light. We study linear and nonlinear coupling of both power and momentum of an optical vortex beam launched into one of the ring cores, and demonstrate that the switching takes place well below the collapse threshold. The switching is more effective for the inner-ring excitation since it triggers more sharply and for the lower power enough to avoid the beam azimuthal instability.