▎ 摘　　要

We propose a dielectric coated graphene-dielectric-graphene multilayer structure and study the input-output property of the structure. Using the boundary conditions of electromagnetic fields at all interfaces, the analytical expression of transmitted field as a function of the incident field is obtained. The optical bistability and multistability are found, and the influence of cladding layer and Fermi energy of graphene on bistability is discussed. We find that the low threshold is obtained by adjusting cladding layer. A reduction by two orders of magnitude in the threshold compared with the no cladding layer case.