The Asymmetric Active Coupler: Stable Nonlinear Supermodes and Directed Transport

TL;DR

This paper introduces the asymmetric active coupler, revealing stable nonlinear supermodes and nonreciprocal dynamics that enable directed power transport and optical isolation, expanding understanding beyond parity-time symmetric systems.

Contribution

It demonstrates the existence of stable nonlinear supermodes in asymmetric active couplers without parity-time symmetry, and shows their potential for nonreciprocal optical transport.

Findings

Existence of finite-power, constant-intensity nonlinear supermodes.

Nonreciprocal dynamics enabling directed power transport.

Potential for optical isolation applications.

Abstract

We consider the asymmetric active coupler (AAC) consisting of two coupled dissimilar waveguides with gain and loss. We show that under generic conditions, not restricted by parity-time symmetry, there exist finite-power, constant-intensity nonlinear supermodes (NS), resulting from the balance between gain, loss, nonlinearity, coupling and dissimilarity. The system is shown to possess nonreciprocal dynamics enabling directed power transport and optical isolation functionality.