Magnetoquasistatic Resonances of Small Dielectric Objects

Abstract

A small dielectric object with positive permittivity may resonate when the free-space wavelength is large in comparison with the object dimensions if the permittivity is sufficiently high. We show that these resonances are described by the magnetoquasistatic approximation of the Maxwell's equations in which the normal component of the displacement current density field vanishes on the surface of the particle. They are associated to values of permittivities and frequencies for which source-free quasistatic magnetic fields exist, which are connected to the eigenvalues of a magnetostatic integral operator. We present the general physical properties of magnetoquasistatic resonances in dielectrics with arbitrary shape. They arise from the interplay between the polarization energy stored in the dielectric and the energy stored in the magnetic field. Our findings improve the understanding of resonances in high-permittivity dielectric objects and provide a powerful tool that greatly simplifies the analysis and design of high index resonators.

References in corpus (5)

• Magnetic light
• Light interaction with photonic and plasmonic resonances
• Multipolar nonlinear nanophotonics
• Material-independent modes for electromagnetic scattering
• Electromagnetic modes and resonances of two-dimensional bodies

Cited by in corpus (9)

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• Time-Domain Formulation of Electromagnetic Scattering Based on a Polarization Mode Expansion and the Principle of Least Action
• Lower Bounds to the Q factor of Electrically Small Resonators through Quasistatic Modal Expansion
• Static surface mode expansion for the full-wave scattering from penetrable objects
• Excitation of a homogeneous dielectric sphere by a point electric dipole
• Electromagnetic Scattering by Networks of High-Permittivity Thin Wires