Graphene-coated Surface Core Fiber Polarizer

In this thesis,we proposed and researched the characteristics of the surface core fiber?SCF?,some attractive optical properties of the fiber are given.Further more,we studied the photoelectric characteristics and applications of graphene,a new surface plasmonic material.Polarization characteristics and optimal structure designing of the graphene-coated surface core fiber polarizer are investigated theoretically and experimentally.The main work and achievements are summed up as follows:1.The characteristics of mode,birefringence and evanescent field of SCF are theoretically studied in detail with the finite element method?FEM?.SCFs have a nonzero cutoff frequency when the fiber core is located in the boundary of cladding.The max birefringence achieves 1×10^-4,and the energy ratio of evanescent wave reaches up to 0.15%.2.The polarization characteristics of SCF based-graphene are researched in detail with Comsol Multiphysics.The results of mode analysis show that TE surface polasmonic wave can propagate along the surface of graphene,which confirms the feasibility of our topic.We analyze the polarization mechanism that is attributed to the differential attenuation of two polarization modes.We also studied the relation between polarization characteristics and fiber parameter or incident wavelength.3.The optimal structure designing are invetgated:one is coating a polymer film?PMMA?,another is a kind of periodic structure based on multilayer graphene.We mainly research the former.The varying relations of the former between polarization characteristics and fiber parameter,thickness of PMMA or incident wavelength are investigated in detail.The extinction ratios of 25.1dB and 26.0dB can be achieved for TE-pass polarized wave and TM-pass polarized wave,respectively,when the length of graphene sheet is 3mm,?=1550nm,the ellipticity of fiber core is e=1/2,the thichness of PMMA is h=800nm.4.We successfully prepared the samples,and established the system to test the polarization characteristics of samples.We achieve a TE-pass polarizer with the extinction of around 3.5dB,compared to the theoretical value 3⁵dB,when the length of graphene sheet is about 6.5mm,?=1550nm,e=1,h=800nm.