Analysis of plasmonic Bloch waves and band structures of 1D plasmonic photonic crystals

Abstract

We consider such passbands that appear due to excitation of plasmons inside the one-dimensional photonic crystal with elementary cells containing layers of positive and negative permittivities. The corresponding Bloch waves can be regarded as surface plasmon chains that are subsequently excited at the layers’ boundaries. The band structure depends on the elementary cell composition that also determines the plasmon type. The excited plasmons can be similar to surface plasmons that propagate along a dielectric slab “sandwiched” between two semi-spaces with negative permittivity, or to surface plasmons that propagate along a negative permittivity slab sandwiched between two dielectric semi-spaces. It is shown that the existence of negative refraction does not depend on the frequency dispersion of permittivity. The latter fact permits us to distinguish six elementary cell compositions with qualitatively different band structures. The frequency evolution of the band structure of a plasmonic PC with a given frequency dispersion of the permittivity can be considered as a transition between various kinds of band structures.