The Line Shape of Double-Sided Tooth-Disk Waveguide Filters Based on Plasmon-Induced Transparency

We numerically investigate a coupled-resonator structure consisting of a stub resonator and a nanodisk resonator using a two-dimensional finite element method. Simulation results show that plasmon-induced transparency （PIT） occurs in the transmission spectra, and the sharp asymmetric Fano lines increase the sensitivity to 1.4 ×10^3 nm/RIU. We also analyze the properties of the structure with different radii of the nanodisk and the length of the tooth cavity. Moreover, we find that the PIP only happens when the staggered system is around a fixed location with different separate distances, which is not similar to the previous researches. Our model may be important to photonic-integrated circuits and the sensitivity in sensors.