Plasmon induced transparency and refractive index sensing in two nanocavities and double nanodisk resonators

Abstract

Two novel implementations for plasmon-induced transparency (PIT) based on two rectangular nanocavities coupled to a bus waveguide and two nanodisk resonators have been studied and simulated with Finite Difference Time Domain (FDTD) method with Perfectly Matched Layer (PML) boundary conditions. It is shown that the wavelength, transmission and width of the PIT peaks can be tuned by changing the radii of the nanodisk resonators and the gap width. Benefitting from the narrow-appeared transparency windows, the proposed PIT-structures can act as nanosensors with refractive index sensitivity and a figure of merit equal to 800 nm. RIU−1 and 61.55 RIU−1, respectively. The proposed devices have potential nanophotonic applications due to simple geometry, compactness and their resistance to the oxidation.