The sensing characteristics based on electromagnetically-induced transparency-like response in double-sided stub and a nanodisk waveguide system

Abstract

We propose a novel metal–insulator–metal (MIM) waveguide structure consisting of a stub and a double side-coupled nanodisk. Its electromagnetically-induced transparency (EIT)-like response and transmission properties are numerically investigated by the finite element method (FEM). Numerical simulation results show that the EIT-like phenomenon appears in the transmission spectra. The transparency window can not only be manipulated by changing the radius of the nanodisk and the height of the stub, but also appear redshifted with the increasing of the refractive index n. Furthermore, the MIM waveguide structure is easy to yield a high sensitivity of 1200 nm/RIU with a figure of merit about [Formula: see text], which may be applied to nanosensors. These results would help us design the high-performance plasmonic devices based on the EIT-like response.