Super-resonances in microspheres: extreme effects in field localization

TL;DR

This paper discovers optical super-resonance modes in dielectric microspheres that significantly enhance internal fields, revealing new phenomena related to magnetic nanojets and giant magnetic fields.

Contribution

It introduces the concept of super-resonance modes linked to internal field poles, expanding understanding of optical resonances in microspheres.

Findings

Field-intensity enhancement factors of 10^4-10^5

Connection to magnetic nanojets and giant magnetic fields

Analytical calculation of super-resonance modes

Abstract

We reveal the existence of optical super-resonance modes supported by dielectric microspheres. These modes,with field-intensity enhancement factors on the order of 10^4-10^5, can be directly obtained from analytical calculations. In contrast to usual optical resonances, which are related to the poles of the electric and magnetic scattering amplitudes, super-resonance modes are related to the poles of the internal field coefficients, obtained for specific values of the size parameter. We also reveal the connection of these super-resonances in the generation of magnetic nanojets and of giant magnetic fields in particles with high refractive index.