▎ 摘　　要

A graphene-based plasmonic valley-slot waveguide modulator has been presented, which consists of a layer of graphene-Al2O3-graphene and two trapezoidal metal strips separated by valley-slot region. Designed modulator has advantage of enhancement of mode confinement and provides an electro-optic modulation with 'proper' (graphene's in-plane) electric field of surface plasmons. The influences of geometric parameters and chemical potential of graphene on modulator performance have been investigated. By optimizing the geometric parameters, the designed modulator could achieve a 3 dB modulation depth only with 290 nm long waveguide and low energy consumption of 1 fj/bit. Also, this modulator can work over a broad wavelength range from 1400 to 1600 nm. These results indicate that proposed modulator could be applied as a high performance broadband optical modulator in photonic integrated circuits.