▎ 摘　　要

A graphene layer has high absorption with very low thickness. The chemical potential of graphene change by an applied voltage and then it leads to the variable optical absorption of graphene. These properties make graphene a suitable absorber layer in optoelectronic devices. The graphene layer is placed in the position of the maximum optical field that causes the maximum absorption. In this paper, an electro-optics modulator is designed with one and two graphene layers with the sub-wavelength thickness. The applied voltage causes change in the chemical potential of graphene and causes change in the graphene absorption. Therefore, the propagating wave would be modulated. The presence of the graphene layer has caused the proposed modulator to have a relatively uniform response in a broad range of frequencies. Simulations show that increasing the number of graphene layers improved the modulation properties. This modulator has a very low thickness and can be integrated into optical circuits. This modulator is applicable in mode-locking laser systems.