Graphene electro-optical modulator and preparation method thereof

The invention provides a graphene electro-optical modulator and a preparation method thereof. The graphene electro-optical modulator is in a plate capacitor structure and comprises an optical substrate, a bottom graphene layer, an insulating layer and a top graphene layer, and the optical substrate, the bottom graphene layer, the insulating layer and the top graphene layer are arranged sequentially from bottom to top. The top graphene layer and the bottom graphene layer are in mutual insulation through the insulating layer, the top graphene layer is above the bottom graphene layer, and an external modulation voltage is applied to the bottom graphene layer and the top graphene layer. The graphene electro-optical modulator is an active Q modulation device independent of a waveguide structure on the basis of a graphene electro-optical modulation technology; modulation depth is changed by amplitude variation of the external periodic voltage, and light modulation depth requirements of different laser parameters can be met; after the graphene electro-optical modulator is inserted into a laser, high-pulse-energy controllable-repetition-rate pulse laser output can be achieved. Therefore, the graphene electro-optical modulator has a promising market prospect.