Design of the voltage tunable side-coupled asymmetric Y-type resonance cavity MIM filter based on surface plasmon polaritons

Abstract

A voltage tunable filter based on a combined metal-insulator-metal nano-cavity waveguide of organic electro-optical material DAST is proposed by using the side-coupled method. The structure of this kind of filter consists of two Y-type cavities and a rectangular waveguide. The transmission spectra, the resonance wavelength, and the magnetic field distribution of the asymmetric Y-type cavity waveguide metal-insulator-metal structure filter has been calculated and analyzed by the finite element numerical simulation method. The results show that this filter has the features of a smooth transmission spectra, a flat passband with the maximum transmission of 0.97, a stopband with the minimum transmission of 0.001, and a wide bandwidth (full width at half maxima achieved 970 nm). The characteristics of the structure filter can be adjusted not only by changing the structural parameters, but also by applying a control voltage. Thus, the adjustability of the filter is increased, and the filter can realize the filtering function of channel selection of the three optical communication windows at the telecommunication regime. There will be great application prospect for this filter structure in high-density integrated circuits and nano-optics.