Strong coupling of a plasmonic dark mode with photons in a photonic crystal cavity

Abstract

We observe strong coupling between the plasmonic dark mode of electromagnetically induced transparency (EIT) metamaterials with the photons in a 1D photonic crystal cavity in the terahertz frequency range. The observed splitting depends on the strength of magnetic interaction between the plasmon bright-and dark-modes of the EIT metamaterials, demonstrating that the coupling between the dark mode and the cavity photons is mediated by the plasmonic bright mode.