Non-Hermitian Fabry-P\'erot Resonances

TL;DR

This paper investigates non-Hermitian Fabry-Pérot resonances, focusing on exceptional points and the skin effect, providing a comprehensive analysis of their properties and implications for broadband edge localization in high-contrast resonator systems.

Contribution

It introduces a continuous differential model to characterize non-Hermitian resonances and demonstrates the existence of exceptional points and the skin effect beyond subwavelength regimes.

Findings

Established existence of exceptional points from radiation conditions

Proved the skin effect causes broadband edge localization

Analyzed resonant modes using propagation matrix formalism

Abstract

We characterise non-Hermitian Fabry-P\'erot resonances in high-contrast resonator systems and study the properties of their associated resonant modes from continuous differential models. We consider two non-Hermitian effects: the exceptional point degeneracy and the skin effect induced by imaginary gauge potentials. Using the propagation matrix formalism, we characterise these two non-Hermitian effects beyond the subwavelength regime. This analysis allows us to (i) establish the existence of exceptional points purely from radiation conditions and to (ii) prove that the non-Hermitian skin effect applies uniformly across resonant modes, yielding broadband edge localisation.