Detuned square ring resonators for multiple plasmon-induced transparencies in metal–insulator–metal waveguide

Abstract

We propose a metal–insulator–metal (MIM) waveguide with two detuned square ring resonators to achieve on-chip multiple plasmon-induced transparencies (PITs). PITs can be explained by a well-defined phase coupling that can be established between detuned resonances. For third-order detuned resonances, there is one PIT window. For second-order detuned resonances, there are one, two, or three PIT windows, depending on the detuning degree between the two square ring resonators. Electromagnetic simulation based on the finite element method is carried out to calculate the PIT transmission spectrum and electromagnetic field distribution.