Physically Agnostic Quasinormal Mode Expansion in Time Dispersive Structures:from Mechanical Vibrations to Nanophotonic Resonances

TL;DR

This paper introduces a universal QNM expansion method for dispersive wave systems, applicable across various physical domains, and presents a flexible numerical algorithm that functions as a general toolbox for nonlinear eigenvalue problems.

Contribution

It develops a physically agnostic QNM expansion technique for dispersive structures, unifying approaches across mechanics, acoustics, electrodynamics, and quantum physics.

Findings

The algorithm is independent of specific physical systems.

It enables efficient computation of resonances in dispersive media.

The method bridges classical and modern wave physics applications.

Abstract

Resonances, also known as quasi normal modes (QNM) in the non-Hermitian case, play an ubiquitous role in all domains of physics ruled by wave phenomena, notably in continuum mechanics, acoustics, electrodynamics, and quantum theory. In this paper, we present a QNM expansion for dispersive systems, recently applied to photonics but based on sixty year old techniques in mechanics. The resulting numerical algorithm appears to be physically agnostic, that is independent of the considered physical problem and can therefore be implemented as a mere toolbox in a nonlinear eigenvalue computation library.