▎ 摘　　要

We propose and discuss a compact and tunable plasmonic terahertz (THz) metamaterial switch based on graphene microcavity. Due to the joint effect of graphene plasmon resonances and Fabry-Perot oscillations, this metamaterial structure can be switched from the ON state to OFF state with the maximum intensity attenuation larger than 95% (ON-OFF ratio larger than 30 dB). The central frequency of the switch could be tuned in a wide frequency range from 3.6 to 9.6 THz by tuning the Fermi energies of the graphene patterns. Moreover, the metamaterial structure is valid for a wide range of incident angles of both transverse electric (TE) and transverse magnetic (TM) polarizations with the highest Q factor of 15.5. This investigation promises the development of high-performance, widely tunable THz switch in chip integrated photonic circuits without reconstructing the physical structures.