Optical Asymmetry Induced by PT-symmetric Nonlinear Fano Resonances

TL;DR

This paper presents a novel photonic circuit with nonlinear PT-symmetric micro-resonators that exhibit direction-dependent Fano resonances, enabling highly asymmetric optical transport with low power input.

Contribution

It introduces a new type of Fano resonance in a PT-symmetric nonlinear photonic system, demonstrating controllable asymmetric light transport.

Findings

Achieved up to 47 dB optical asymmetry

Resonance features depend on incident light direction

Low input power required for operation

Abstract

We introduce a new type of Fano resonances, realized in a photonic circuit which consists of two nonlinear PT-symmetric micro-resonators side-coupled to a waveguide, which have line-shape and resonance position that depends on the direction of the incident light. We utilize these features in order to induce asymmetric transport up to 47 dBs in the optical C-window. Our set-up requires low input power and does not compromise the power and frequency characteristics of the output signal.