Structure Design Of Graphene-based Modulator And Study Of Its Characteristics

Electro-optic modulator is an important device of Optical fiber communication system. As graphene has a lot of advantages in optoelectronics characteristic, we benefit a lot from manufacturing modulator in graphene. In recent years, so many scientists have researched this issue and get a lot of achievements.In this paper, Mach-Zehnder modulator based on graphene was studied. The theory of modulation was analyzed. At the same time, the parameters of modulator were introduced. Then, the theory of Mach-Zehnder interference was studied. The properties of graphene were analyzed as it can improve the performance of the modulator. The theory of FD-BPM was researched as a method to analyze the modulator.According to the theory of waveguide, the mode of waveguide was studied. The mode of waveguide was simulated by Comsol. The structure of waveguide was ameliorated due to the analysis of the mode. In order to obtain better modulation, a waveguide based on graphene and silicon was designed. In order to maximizing the interaction of graphene and the field, graphene was designed to be distributed in the maximum of the mode. The performance of the waveguide was determined by the effective index. The structure of this waveguide was optimized by fixing the position of graphene.Based on the theory of FD-BPM, the theory of cosine type Y branch waveguide bend was analyzed. The angle of Y branch was ameliorated due to this analysis. A kind of push-pull Mach-Zehnder modulator was designed due to the propertied of graphene. Its transmission was analyzed and the modulation depth, 3dB bandwidth were calculated.