Dynamic Control of Double Plasmon-Induced Transparencies in Aperture-Coupled Waveguide-Cavity System

A theoretical model, for dynamic control of double plasmon-induced transparencies in aperture-coupled metal-dielectric-metal (MDM) waveguide-cavity system, is proposed. Based on the theoretical and numerical results, the formation and evolution mechanisms of double plasmon-induced transparencies are investigated more accurately compared to previous works. The symmetries, positions and measured full width at half maximum (FWHM) of the double transparent windows, and the transmission phase shift can be tuned freely by structural parameters. Moreover, the slot cavity location relative to aperture affects the phase difference between the left and right slot cavities to aperture center and determines the wavelength of resonance mode in aperture-side-coupled slot cavity, which plays an important role in the appearance or disappearance of transparent windows. In particular, supported by the consistency between the theoretical analysis and simulations, we obtain the threshold of coupling distance between two apertures, at which the abrupt phase shift happens. The detailed analysis may open up the possibility for precise control of light in highly integrated optical circuits.