Exceptional point enhanced small particle detection in systems of subwavelength resonators

TL;DR

This paper explores how exceptional points in subwavelength resonator systems can significantly enhance the detection sensitivity of small particles, leveraging multiple scattering techniques and resonance perturbations.

Contribution

It introduces a novel approach using exceptional points and multiple scattering expansion to improve small particle detection sensitivity in high-contrast resonator systems.

Findings

Exceptional points critically influence subwavelength resonances.

Enhanced sensitivity in particle detection near exceptional points.

Numerical experiments validate the proposed sensing technique.

Abstract

This paper considers the effects of small highly contrasted particles on the subwavelength resonances of a system of high-contrast resonators, with an application to sensing. The key technique is a multiple scattering expansion of the capacitance matrix associated with the perturbed system. At leading order, the perturbation of the scattering resonances is characterized by the associated term of the truncated multiple scattering expansion. When an exceptional point is present in the resonance structure, the perturbation critically affects the subwavelength resonances, which improves the sensitivity of a sensing task in the presence of noise. Numerical experiments demonstrate the use of the proposed reconstruction techniques.