Aperture-coupled Plasmonic Voltage Tunable Filter Based on Asymmetric Micro-ring Resonators

Abstract

A Metal-Insulator-Metal (MIM) voltage tunable filter based on the Aperture-coupled method is proposed, which consists of two micro-ring resonators filled with organic Electro-Optical materials DAST and a rectangular waveguide. The transmission spectrum, resonance wavelength distribution curves and the magnetic field distribution of the asymmetric micro-ring cavities waveguide structure filter have been calculated and analyzed by the finite element numerical simulation method. The results show that the filter has the feature of a smooth transmission spectrum, a wide passband bandwidth (Full width at half maxima can be achieved 520 nm) and stopband bandwidth (Full width at half maxima reaches 50 nm). And the transmittance of the passband is up to 0.97, the transmittance of the stopband can reach 1 × 10−4. When the structural parameters h and R of the filter are increased, the corresponding transmission spectrum will have obvious red shift, and the transmittance of the different resonant modes will not change. In addition, the change of the resonance wavelength has a linear relationship with the change of the structural parameters h and R. When the structural parameter d is increased, the positions of the different resonant modes are almost unchanged. By adjusting the voltage, the transmission spectrum of the filter also occurs red shift, and the resonance wavelength increases linearly with the increase of the voltage. The characteristics of the filter can be adjusted not only by changing the structural parameters, but also by applying a control voltage, the adjustability of the filter is increased. Therefore, the filter is of great significance in high-density integrated circuits and nano-optics.