Non-radiative surface plasma-polariton modes of inhomogeneous metal circular cylinders

Abstract

The theory is given of the non-radiative surface plasmon-polariton modes of metal cylinders, modelled by a spatially dispersive free electron gas within a Bloch hydrodynamic formulation. Dispersion equations for homogeneous and inhomogeneous cylinders are derived for nth cylindrical harmonic, and the dispersion properties are investigated as a function of n, cylindrical radius and surface structure. The position, and splitting with n, of the surface modes is found to be considerably different from those based on a model that neglects spatial dispersion. This is particularly true for very small cylinder radii.