Coupled surface-plasmon-polariton waves and the optical size effect on the optical reflectance of metal-insulator superlattices.

Abstract

We have solved the dispersion relations of the transverse wave vector Q(\ensuremath{\omega}) and the longitudinal Bloch wave vector p(\ensuremath{\omega}) for a p-polarized wave incident on a semi-infinite metal-insulator superlattice constricted by the optical size effect. The optical reflectance obtained by solving a transfer-matrix formalism approaches zero as the incident-photon frequency exceeds the volume plasma frequency ${\mathrm{\ensuremath{\omega}}}_{\mathit{p}}$. Reflection peaks are observed only at frequencies near ${\mathrm{\ensuremath{\omega}}}_{\mathit{p}}$, whereas a reflection minimum can occur at \ensuremath{\omega}${\mathrm{\ensuremath{\omega}}}_{\mathit{p}}$/ \ensuremath{\surd}2 for sufficiently small values of the insulator thickness and specularity parameters p and q.