Localized Surface Plasmon Resonance Characteristics Of Graphene Nanostructures

Graphene is a planar sheet of sp~2-bonded carbon atoms in a hexagonal lattice of flat film. Its unique two-dimensional structure impacts graphene many special excellent properties. Such as superior electrical conductivity, excellent mechanical properties, unique optical properties and thermal properties. Localized surface plasmons (LSP) is a kind of electromagnetic mode casued by the interaction between the free charges on the graphene surface and the incident electromagnetic wave, and the oscillation is limited on the surface of the structure. The Localized surface plasmon resonance (LSPR) of graphene nanostructure shows strong electric field effect, making many optical effects become more significant, so the LSPR of graphene nanostructure can be widely used in many important fields, such as the Biochemical sensing, information and communications, military et al.This article studied the LSPR properties of graphene nanostructures. The graphene wedge-shaped and film (GWSF) structure array and graphene pseudo-dolmen (GPD) structure array are designed to systematically study LSPR properties based on numerical simulation software COMSOL Multiphysics, the main contents and results are as follows:(1) The graphene wedge-shape and film structure is composed of the upper wedge-shape and lower film. This paper studied LSPR properties of the structure, and discussed the influence of the parameters and the Fermi energy on the transmission property. The study founds:higher mode is excited at short wavelength and dipole electric oscillation is excited at long wavelength. In addition, the LSPR properties of GWSF structure strongly dependents on the structural parameters and the Fermi energy, the resonant modes blue shift or red shift by changing parameters and Fermi energy. Therefore, it can be applied to the probe, filters and so on.(2) The graphene pseudo-dolmen (GPD) structure consists of three rectangles which perpendicular to each other. This article studied double Fano resonance property and the influence of the structural parameters and Fermi energy. The study founds:the bright mode is excited directly by the electric field polarization and two black modes are excited indirectly by electric field coupling, this structure can achieve double Fano resonances phenomenon. Meanwhile, these three modes can be lonely tune by varying the structural parameters and Fermi energy. So, this structure plays an important role in Sensors and filters aspects.