Equi-Reflectance Dual Mode Resonance Using Bimetallic Loaded Dielectric Plasmonic Structure

Theoretical study of the reflectance response of an asymmetrically-clad bimetallic film that supports coupled surface plasmon polariton modes has been presented. Through adjusting the relative thickness of the two metal film components, the relative coupling strength to the long range (LR) and short range plasmon modes can be altered. It is possible to obtain optimal and equi coupling (zero reflectivity) to both modes for given incident wavelength by further adjusting the overall thickness of bimetallic film. Simultaneous angular and spectral sensitivity calculations of resonance of the LR mode have been demonstrated for sensing application. Tailoring of the structure of individual metal films realizing equi- and non-equi-reflectance modes has been proposed which may further be used for plasmonic trinary logic using binary di-bit images.