Analysis of Mie resonances using the Debye series.

Abstract

Scattering of light from homogeneous spherical particles can exhibit sharp resonances as functions of particle size, wavelength, or refractive index. Such resonances, usually known as morphology-dependent resonances or whispering gallery modes, have been exhaustively studied using Mie theory. This paper demonstrates that the Debye series expansion provides a succinct and easily understood representation of these resonances: For example, the Debye coefficient Rn121 determines (a) the exact conditions for resonance, (b) the number of terms required to replicate the Mie result, and (c) the Q-factor of the resonance.