Low-frequency surface-plasmon resonances in planar metal-dielectric periodic structures

As a part of nanophotonics, surface-plasmon resonance is examined for a periodic semi-infinite structure with metal-dielectric unit cells in slab geometry. The electromagnetic waves through this structure are analyzed in the low-frequency limit with respect to the bulk plasma frequency of metal. The lossless Drude model is employed throughout the present paper for mathematical simplicity. As a consequence, a distinguished balance is found to exist, where the similarity parameter is formed from an appropriate combination of the filling fraction of the metallic sublayers and the frequency. Interesting nanophotonic behaviors are thus identified by comparing various characteristics such as the frequency bandgaps, cutoff thicknesses, substrate effects, acoustic and optical modes, and group-velocity dispersions.