▎ 摘　　要

An appropriately designed periodic lattice in graphene can cause plasmonic modes, absorbing a specific THz frequency band, minimizing transmission. A suitable Fabry-Perot cavity, on the other hand, can resonate at another desired frequency in the nearby THz band, enhancing the transmittance. Integrating, these two types of structures into a THz switch, in which the peaks of the plasmonic absorption and the Fabry-Perot resonance band play the role of the OFF and ON states, yielding a bistable switch with a very high output due to the resonance and a high extinction (ON/OFF) ratio. By placing a patterned with an array of circular micro-holes with a plasmonic absorption band centered about 4.1 THz in the middle of a Fabry-Perot vertical cavity of resonance band centered about 3.9 THz, we have designed a bistable THz switch with 87% transmission in the ON state and the extinction ratio of 23 dB. The optical bistability, in this switch, is the consequence of graphene nonlinear property invoked by the enhanced optical intensity due to the cavity resonance, adding an intensity-dependent term to the graphene surface conductivity.