Research On Electro-Optical Modulating Properties Based On Graphene Photonic Crystal Fiber

With the rapid development of the Internet and Communication industry,human beings have higher requirements for information acquisition and transmission.As one of the main technical pillars of informatization,optical fiber communications is also moving towards higher goals.A key component of optical fiber communications for achieving high-bandwidth and high-capacity is high-speed electro-optic modulation.As a kind of unique zero bandgap energy band structure material,graphene has many excellent electrical and optical properties and has been widely used in the research of optoelectronic devices in recent years.Therefore,in this paper,two kinds of modulators with different structures are designed by combining graphene with photonic crystal fibers,aiming at exploring optoelectronic devices with high performance.The main contents of the paper are as follows:Firstly,based on the understanding of traditional modulators,the research status of graphene-based material modulators is summarized,and the classification and characteristics of photonic crystal fibers are analyzed in detail.Starting from the graphene band structure,the linear optical properties,nonlinear optical properties and other characteristics of graphene are analyzed,and the finite element method used in the study is briefly introduced.Secondly,a graphene-based photonic crystal fiber electro-absorption modulator model is designed.Above all,the principle and performance parameters of the modulator are introduced.Then the fiber pattern is analyzed and the control characteristics of composite structure are explored.And the influence of fiber structure parameters,the wavelength of incident light and the number of graphene layers on the modulation performance are theoretically studied.Thirdly,in order to reduce the voltage,the effect of adding an oxide barrier layer on the graphene layer is mainly analyzed.And the influence of fiber structure parameters,the number of graphene layers and the thickness of the Al₂O₃ on the modulation performance are theoretically studied.Lastly,a graphene-like panda-type photonic crystal fiber phase modulator model is designed.By filling the graphene into large symmetrical air holes,the mechanism of phase modulation is analyzed.Then the influence of fiber structure parameters,graphene carrier mobility and the number of graphene layers on the phase modulation are subsequently explored.Finally,the stability of the phase modulation at different incident wavelengths is also analyzed.