Study Of Graphene-Microring Optical Mudulator Based On SOI

In high-speed and short-range optical communication,the optical modulator is one of the most important integrated optical devices affecting the transmission efficiency of an optical communication network.Due to the disadvantages of large device size and limited modulation bandwidth,the traditional optical modulator cannot meet the increasing demand for information transmission.Graphene,a new two-dimensional material,has ultra-high carrier mobility and unique electrical properties which are compatible with CMOS technology.It is of great significance for the design of new optical modulators.In this paper,graphene is combined with silicon waveguide to study graphene optical modulator with high bandwidth,high extinction ratio,and low loss.Firstly,a single-layer graphene thermooptic microring modulator based on SOI is designed.By analyzing the thermooptical effect and the basic theory of the microring resonator,the structural parameters of the device are optimized.The graphene heat-conducting electrode is used to replace the traditional Thermoelectrode so that the graphene can be in direct contact with the silicon waveguide to ensure the rapid transfer of heat.Thanks to the ultra-high thermal conductivity of graphene,the graphene thermooptic modulator has good thermal modulation characteristics.The simulation results show that the extinction ratio of 25.18 d B is achieved near the wavelength of 1550 nm,the full width at half maximum(FWHM)is 3.6 nm,and the thermal efficiency is 2.38 nm / MW.The rise time and fall time of the device are only 2.4 μs and 2.2 μs.Experimentally,the water fishing transfer method of single-layer graphene film was studied.It was characterized by an optical microscope and Raman spectrum,and the quality of graphene film was effectively judged.The graphene thermooptic microring modulator chip based on SOI was prepared,the test platform was built,and the performance of the device was tested.In order to further improve the performance of the modulator,the effects of the number of graphene layers and the thickness of the dielectric layer on the hybrid waveguide are discussed,and a graphene electro-optic microring modulator based on SOI is proposed.By introducing the double-layer graphene structure,the excellent electro-optical properties of graphene are fully utilized,and the structural parameters of the device are optimized by simulation.The modulation performance of the device is analyzed and summarized in detail.The results show that the extinction ratio of the modulator is 40.04 d B,the FWHM is 2.9 nm,and the device energy consumption is only 22.0 f J/bit.In this paper,a graphene electro-optic modulator with a high extinction ratio,low energy consumption,and wide bandwidth is realized.This work provides a certain reference value for the application and development of graphene optoelectronic devices.