▎ 摘　　要

We propose a kind of gradient metasurface based on graphene apertures for wavefront control of terahertz linear polarized waves. By carefully designing the geometric dimensions of the graphene rectangular apertures, the proposed metasurface can realize arbitrary reflection, carpet cloak and reflective focusing, respectively. The simulation results demonstrate that the cloaking and focusing effects can be actively tuned between ON and OFF state by uniformly tuning the graphene Fermi energy. The metalens based on graphene has high-efficiency, broadband and wide-angle off-axis focusing performance, and the focusing efficiency is significantly dependent on graphene Fermi energy and carrier mobility. When the mobility decreases from 1.0 m(2)/Vs to 0.1 m(2)/Vs, the focusing efficiency decreases from more than 70% to about 22% at the operating frequency. The tunable and efficient performance makes the graphene aperture based metasurface have great application potential in ultrathin, lightweight and integrated terahertz devices.