Nonreciprocal switching thresholds in coupled nonlinear microcavities

TL;DR

This paper proposes a new design for nonlinear optical diodes using coupled microcavities that exhibit direction-dependent switching thresholds, enabling nonreciprocal light transmission with minimal loss.

Contribution

It introduces a novel concept leveraging multistability and mode parity in coupled microcavities for nonreciprocal optical switching, supported by a coupled mode theory model.

Findings

Achieves strong nonreciprocal behavior with negligible insertion loss.

Demonstrates potential implementation in multilayered structures.

Provides a theoretical framework for designing nonlinear optical diodes.

Abstract

A novel concept for the design of nonlinear optical diodes is proposed which uses the multistability of coupled nonlinear microcavities and the dependence of switching thresholds on the direction of incidence. A typical example of such diode can be created by combining two mirror symmetric microcavities where modes of the opposite parity dominate. It is shown that a strong nonreciprocal behavior can be achieved together with a negligible insertion loss. To describe the dynamical properties of such systems, a model based on the coupled mode theory is developed, and a possible implementation in the form of multilayered structures is considered.