The Study Of Phase Modulator Based On Slot Waveguides And Graphene

With the development of optical communication network(OCN),the application of OCN has congested in human's lives.In all kinds of photonic devices,electro-optic(EO)modulator can convert between electrical signals and optical signals,therefore it is one of the most important functional devices.However,the drawbacks of EO modulator based on plasma dispersion effect such as large footprint and narrow bandwidth have hindered its development.To solve this problem,graphene modulators(GMs)are studied in this paper.The performance of GMs is highly depended on the interaction between light and graphene.Therefore,to further enhance the interaction strength,we propose two phase GMs based on slot waveguides and an absorptive modulator based on hybrid waveguides.Its working mechanism and performance are analyzed and investigated.The main research contributions of this paper can be summarized as follows:(1)To solve the problem of weak interaction between light and graphene in GMs,we design a novel Mach-Zehnder phase GM based on slot waveguides.Due to the light-intensity enhancement of slot waveguides,the interaction between light and graphene is improved.The proposed modulator exhibits the advantages of high modulation efficiency(0.042 V·cm),large modulation bandwidth(79.6 GHz)and low energy consumption(0.32 pJ/bit).(2)To solve the problem of narrow working bandwidth of microring modulators,we design a novel graphene microring phase modulator based on slot waveguides.The working bandwidth is improved and the shift rate of the resonance peak reaches 1.42 V/nm.(3)To solve the problem of large footprint of the traditional absorptive GM based on strip waveguides,we design a novel absorptive GM based on the hybrid waveguide.The modulation efficiency of the GM based on the hybrid waveguide is two times larger than that of GMs based on strip waveguides,which results in a smaller footprint.