Fano resonance in a MIM waveguide structure with chiral gammadion resonance cavity

A compact plasmonic nanosensor has been described, which consists of a metal–insulator–metal (MIM) waveguide and two symmetric rectangular stubs coupled with a gammadion resonance cavity (GRC) with chiral properties. The transmission characteristics and magnetic field distribution of the MIM waveguide structure are simulated by employing the finite element method (FEM). Results revealed that a Fano resonance is excited in the designed whole waveguide system. The Fano resonance can be tuned by the structural parameters of the waveguide system. The MIM waveguide structure with optimized parameters can be applied in identify different concentrations of glucose solution. The sensitivity achieves up to 945 nm/RIU. This proposed structure has potential applications in the biosensors and optical communications.