Nonuniqueness of the quasinormal mode expansion of electromagnetic Lorentz dispersive materials
Language
en
Article de revue
This item was published in
Journal of the Optical Society of America. A Optics, Image Science, and Vision. 2020, vol. 37, n° 7, p. 1219
Optical Society of America
English Abstract
Any optical structure possesses resonance modes, and its response to an excitation can be decomposed onto the quasinormal and numerical modes of a discretized Maxwell operator. In this paper, we consider a dielectric ...Read more >
Any optical structure possesses resonance modes, and its response to an excitation can be decomposed onto the quasinormal and numerical modes of a discretized Maxwell operator. In this paper, we consider a dielectric permittivity that is an N-pole Lorentz function of the frequency. Even for discretized operators, the literature proposes different formulas for the coefficients of the quasinormal-mode expansion, and this comes as a surprise. We propose a general formalism, based on auxiliary fields, which explains why and evidences that there is, in fact, an infinity of mathematically sound possible expansion coefficients. The nonuniqueness is due to a choice of the linearization of Maxwell’s equations with respect to frequency and of the choice of the form of the source term. Numerical results validate the different formulas and compare their accuracy.Read less <
English Keywords
Electromagnetic resonance
Quasinormal mode
Microcavity
Nanoresonator
Modal expansion
ANR Project
Théorie et modélisation numérique des résonances optiques - ANR-16-CE24-0013
Origin
Hal imported