Switchable efficiency terahertz anomalous refraction and focusing based on graphene metasurface

In this paper, a graphene metasurface based on split-ring resonators (SRRs) structure has been proposed and investigated numerically, which can achieve the highly efficiency switchability of anomalous refraction and planar focuing effects. Numerical simulation results indicated that the proposed graphene metasurface could not only realize polarization conversion with a transmission amplitude of about 0.4, but also achieve a full 2 pi phase shift by changing the geometrical parameters of SRRs structure. In addition, the efficiency of the cross polarization transmission is highly depedent on the Fermi energy level of graphene. By elaborating design of a spatially phase profile and arrangment of unit-cell structure, anomalous refraction and planar focusing effect can be achieved, and the efficiencies are also switched by only changing the Fermi energy level rather than the physical size. It could be believed that the effective switchable graphene metasurface would lead a new path for controling the wavefront of THz waves.

Automated summary

This paper proposes and numerically investigates a graphene metasurface based on split-ring resonators (SRRs) structure, which can achieve highly efficient switchability of anomalous refraction and planar focusing effects. Numerical simulation results show that the proposed metasurface can realize polarization conversion with a transmission amplitude of about 0.4 and achieve a full 2 pi phase shift by changing the geometrical parameters of the SRRs structure. Furthermore, the efficiency of cross polarization transmission is highly dependent on the Fermi energy level of graphene. By designing a spatially phase profile and arrangement of unit-cell structure, anomalous refraction and planar focusing effect can be achieved, with the efficiencies switched by changing the Fermi energy level rather than the physical size.