Dual-waveguide stacked graphene light modulator based on an MZI structure

In order to solve the defects of the high driving voltage and a large volume of the existing electro-optical modulators, a double-waveguide stacked graphene optical modulator based on a Mach-Zehnder Interferometer structure is designed in this paper. First, the modulator size of traditional planar structure is effectively reduced by stacking two modulators vertically. Secondly, by changing the relative position of the electrode and the waveguide, the coupling effect of the electrode and the waveguide is enhanced, and the driving voltage is reduced. Finally, the performance of the designed electro-optic modulator is verified by the finite element method. The half-wave voltage of 0.55 V · cm and the modulation bandwidth of 58.8 GHz are realized on the basis of the length of 1.14 mm. The insertion loss is 1.15 dB, and the return loss is -44.8dB.