Research On The Graphene-based Silicon Subwavelength Electro-optic Modulator

Optical fiber communication technology is an important support for modern information technology.It is of great significance to develop higher performance electro-optic modulators in optical fiber communication technology.In recent years,many silicon-based electro-optic modulators based on graphene have been successfully made and extensively studied.However,in such devices,the interaction between graphene and light is so weak that causes a low modulation efficiency and a large device size.In order to solve these issues,a circular-hole sub-wavelength electro-optical modulator based on graphene to improve modulation performance dramatically was proposed.The main contents of this paper are as follows:(1)Based on the study of the basic properties of graphene,a graphene-applied voltage modulation model was established,and the traditional graphene modulator was analyzed theoretically.Based on the defects of traditional graphene modulators,a theoretical model of graphene-based circular-hole-type sub-wavelength waveguide composite structure was proposed.This structure can reduce the restriction of the waveguide to the light field,which will greatly enhance the interaction effect between graphene and light.(2)Based on the established theoretical model,a modulation performance optimization method for graphene electro-optic modulator was proposed.Compared with the recently reported modulation efficiency of 0.025 d B/ for graphene absorption modulators and the modulation efficiency of 2.8 V·mm for graphene phase modulators,graphene-based subwavelength electro-optic modulators can reach 0.272 d B/ and 0.43 V·mm,the modulation efficiency have been greatly improved and the devices size have been reduced,which are conducive to the development of the device toward miniaturization and high efficiency.(3)The process of our graphene-based sub-wavelength electro-optic modulators was studied and designed.The layout design was completed using the L-edit software.The preparation of the designed device was completed according to the specific steps of the process flow.A test system was set up for the prepared device,the performance testing and analysis of the device were performed.Based on the process problems and test results,the future ideas and suggestions for the experimental preparation of graphene-based sub-wavelength silicon electro-optic modulators were proposed.