Graphene–Gold Nano-ring antenna for Dual-resonance optical application

• In this paper, we show the different characteristics of optical gold and graphene for making a dual band nano antenna in Infra red regime for bio sensing.
• In continue, here was debated about the effect of these structures on the nano particle bonding and antibonding modes and the particle dipole and quad resonances.
• By biasing the graphene, we are able to designed reconfigurable structure.
• Therefore, the biasing effect on transition is studied for 0.1–0.4 eV.

To achieve dual resonance qualification, we are suggested a sub-wavelength dual-ring Nano-antenna based on combination of Graphene and gold where Nano-Antenna with dual-resonance is attractive for spectroscopy and bio-sensing applications. The result shows that with these structures, we could be achieved dual-resonance characteristic of Infra red (IR) and optical regime. In addition, by biasing of the Graphene, we are attained a reconfigurable characteristic for our second resonance. Therefore, in this current research, the extinction, reflection and absorption cross section are studied for every structure and formation. For modeling the prototype Nano-antenna, SiN Substrate is selected with refractive index of 1.98 and silver with Palik optical characteristic for metal layer is modified. Simulation has been done with FDTD method. Of course, because of symmetry of the structure, the prototype Nano-antenna has similar manner for vertical or horizontal polarization. As a result, proposed Nano-antenna is useful for THz medical spectroscopy with simple method of designing and second frequency controlling only with graphene biasing. Here, we are debated about graphene placement and biasing interaction on the bonding and anti-bonding mode where we show that the gold and graphene interaction will affect on E-field distribution by making dipole or quad resonance.