▎ 摘　　要

We propose and discuss terahertz (THz) electro-optic modulator induced by periodically patterned graphene micro cavity. Due to the joint effect of graphene plasmon resonances and Fabry-Perot (F-P) oscillations, plasmon-induced transparency (PIT) effect is achieved and the operation frequency can be dynamically tuned by graphene Fermi energies and structural parameters. The results reveal that modulation depth (MD) larger than 80% is obtained across a wide frequency range from 4.2 THz to 9.4 THz, and the largest MD and Q factor reaches 95% and 15.8, respectively. In addition, operation frequency range and MD can also be tuned by optimizing the structure parameters. This investigation promises the development of high-performance widely tunable THz modulator in chip integrated photonic circuits.