A new optical sensor based on the surface plasmon resonance (SPR) is proposed and characterized. The sensor is composed by sandwiching the graphene sheets between two metal films in the Kretschmann configuration. The resonance angle and the sensitivity of proposed sensor are analyzed through the transfer matrix method. Moreover, the refractive index change of the analyte can be detected accurately by using the proposed sensor. It is observed that the sensitivity of the proposed bimetallic sensor configuration can be greatly enhanced than conventional single metal configuration by optimizing the thickness of the metals and the number of graphene layers. Finally, we believe that the proposed SPR configuration can further promote the biosensing application.
Plasmonic-induced transparency (PIT) in the metal-insulator-metal plasmonic waveguide with two side-coupled rectangular ring disk structures is numerically investigated. The PIT resonance occurs as a consequence of the destructive interference between the two structures. It is found that the transmittance can be easily adjusted by changing the parameters of the structure and coupling distance between the structure and waveguide. By optimizing the parameters, the transmittance of the structure can up to 75% in our discussion. These results may have important applications for designing integrated devices such as narrow-frequency optical filters, novel sensors and high-speed switches.