Tunable coupling-induced transparency band due to coupled localized electric resonance and quasiguided photonic mode in hybrid plasmonic system.

A numerical and theoretical study is presented on the exhibition of tunable narrow band coupled-induced transparency phenomenon in a hybrid waveguide-plasmon system consisting of gold twin nanowires array embedded in a slab waveguide. We show that, at slightly non-normal incidence, a properly designed splitting of transmission with narrow transparency peaks may occur at a given wavelength, depending on the angle of incidence. This leads to the wavelength-selective high quality coupled-induced transparency resonance at optical frequencies. By adjusting the gap distance of the pair gratings, the coupled-induced transparency band can be switched between on-state and off-state, which provides us possibilities to develop controllable plasmonic functional devices employing plasmonic nanostructures.