The optical Tamm states at the interface between a photonic crystal and nanoporous silver

The optical Tamm states (OTSs) localized at the edges of a photonic crystal bounded by a nanoporous silver (NPS) film are investigated. NPS involves spherical vacuum nanopores dispersed in the metal matrix and is characterized by the effective resonance permittivity. The transmission, reflection, and absorption spectra of the structures under study at the normal incidence of light are calculated. It is shown that each Tamm state has its own frequency range where the real part of effective permittivity is negative. The light field localization at the high-and low-frequency OTSs is investigated. The specific features of spectral manifestation of the OTSs are studied in dependence on the nanopore concentration in the metal matrix and on the NPS film thickness.