Extended coupled Lorentz oscillator model and analogue of electromagnetically induced transparency in coupled plasmonic structures

Abstract

We report a new extended coupled Lorentz oscillator (ECLO) model by adding a coupled phase factor for the first time, to the best of our knowledge, in contrast to the conventional coupled Lorentz oscillator (CLO) model for describing the analogue of electromagnetically induced transparency (EIT) in a dimer, which is composed of two identically broken eccentric silver nanorings (ESNRs) arranged in an asymmetric manner. Based on the finite element method, the distribution features of the absorption spectra, the charges, and the electric field of the ESNRs are numerically simulated under the action of the applied light field. The ECLO model reveals the physical mechanism of the spectra features and the EIT-like effect. Our findings indicate that the destructive interference effect plays a key role in the generation of the EIT-like effect. The theoretical analyses are in good agreement with the numerical results.