▎ 摘　　要

Metasurfaces have shown tremendous potentials in controlling wavefront of electromagnetic waves and choosing appropriate structure for wavefront modulation still demands enormous efforts. Here, a gradient metasurface with patterned graphene is proposed to realize tunable modulation of THz waves. The 2 pi lateral phase change of variable patterned graphene structures can allow the realization of anomalous reflection and refraction together in the THz wave. In particular, anomalous conversion efficiencies of refraction and reflection can be dynamically tuned by changing the Fermi energy without resizing graphene structures. Moreover, the properties of the metasurface have been explored for different frequencies and angles of incidence. The tunable resonances in structured graphene provide an opportunity for designing graphene-based metamaterials and offer a new route to control or manipulate THz radiation.