Tunable Fano resonance in a novel compact metal–insulator–metal structure

Abstract

A novel compact scheme to realize tunable Fano resonance is proposed and investigated theoretically and numerically. The scheme is based on two slot cavities in a metal–insulator–metal structure. The model and formation mechanism of Fano resonance in this structure are studied. A new method based on four-mode temporal coupled-mode theory is used to analyze model of the structure with two slot cavities. Compared with previous studies, this method only considers the interaction between modes within two cavities rather than considering the energy coupling between them. The tunability and slow light phenomenon in the new structure are also studied. It is believed that research in this article can provide a new method to achieve Fano resonance. Furthermore, it is helpful to establish the Fano resonance model and reveal the formation mechanism of Fano resonance.