▎ 摘　　要

We design and numerically analyze an all-optical logic gates in the terahertz regime. The structure is composed of four graphene waveguides and a cavity resonator, which is a very simple structure. Due to the Fano resonance exciting in the asymmetry structure, the transmission spectrum can suddenly drops to a minimum value to excite logic "ON/OFF" state. By using this character, XOR, XNOR, and NOT gates can be realized with high contrast ratio of 17.8, 15.2 and 19.1 dB between logical "ON" and "OFF" states, respectively. This study opens a new avenue for designing graphene nanoribbon based integrated circuits.