Fano resonance and Rabi splitting in MDM side-coupled cavities systems

We theoretically investigate the Fano resonance and Rabi splitting in the metal-dielectric-metal plasmonic waveguides with stub resonators. The proposed nanostructure waveguide consists of bulb-like resonators and a thin Metamaterial (MM) baffle. The bulb-like resonator with low Q factor can work as a continuum state, and the plasmonic waveguide inserted with a MM baffle can work as a discrete state. Fano resonances are obtained because of the interaction between the two states in the structure and the Fano resonance can be tuned by changing the separation between the resonator and the MM baffle. In the plasmonic waveguide system with two resonators and a MM baffle, Rabi splitting occurs because of the strong coupling between the narrow spectral response of MM baffle and the Fabry-Perot resonance caused by the two bulb-like resonators The pronounced anticrossing behavior of the splitting peaks can be modified by varying the resonant frequency of MM baffle, the bulb-like resonator's radius and the stub height. Furthermore, it is also found that the Rabi splitting can also be tuned by the separation between resonator and the MM baffle. Such plasmonic waveguide system may have potential applications in providing a stimulating insight to explore new fundamental physics in analogous atomic systems.