Radiative decay of surface plasmons on oblate spheroids

Abstract

We have obtained a general expression for the radiative decay rate of surface-plasmon modes on oblate spheroids in terms of familiar spherical functions. Experimental observations of the polarization, wavelength, and angular dependence of light emitted by electron-bombarded silver spheroids were compared with the theoretical calculations, and good agreement was obtained. We have shown that it is possible to use both nonretarded electrodynamics and bulk-metal optical properties to describe plasmons on particles with 10-40 nm dimensions. The results given can be used to study the angular and wavelength characteristics of other plasmon-related effects such as photoemission and surface-enhanced Raman scattering.