Research On New Micro-structured Fiber Devices

As a new generation of special optical fiber,micro-structured fiber(MSF)can be used to flexibly change its cladding structure and substrate material,and can also be used for rich post-processing.Therefore,the design,research and development of various new MSF devices has become a hot issue in the optical fiber hybrid and integration technology.Although the reported MSF devices have achieved some research results,but there are still some key scientific problems to be solved,such as the combination of actual fabrication and system integration,the singulation of detection scene and working spectral area.Aiming at the above problems,different substrate materials are selected,and gold nano films are coated or liquid crystal are filled into MSF air holes,the full vector finite element method is used to carry out a series of in-depth research on the new MSF refractive index(RI)sensor,polarization filter and polarization beam splitter in theory in this paper.The key research and innovation results are as blows:(1)Using the metal surface plasmon resonance(SPR)effect,the different mode coupling effects of X-polarization(X-pol),Y-polarization(Y-pol)core mode and second-order surface plasmon polariton(SPP)mode under different conditions are analyzed in detail.A MSF-RI sensor based on silica with air hole coated by gold nano film is proposed.The results show that in the ultra wide RI detection range of 1.32～1.48,the average wavelength sensitivity,the maximum resolution and figure of merits of the X-pol and Y-pol core modes reaches-4735.83 nm/RIU and-4525.83 nm/RIU,4.71×10-6 RIU and 4.65×10-6 RIU,134 RIU-1 and 177 RIU-1,respectively.(2)Using the different mode coupling effects between core mode and SPP mode when the metal SPR effect occurs,a V-shape MSF polarization filter based on silica with air hole coated by gold nano film is proposed and researched.The results show that when the device length is 4 mm,the Y-pol core mode is filtered out within the wavelength of 1478～1616 nm,only the X-pol core mode is retained,and the polarization filtering bandwidth can up to 138 nm.A MSF polarization filter based on silicon with air hole coated by gold nano film is proposed and researched,and its filtering characteristics under three different parameters are analyzed.The results show that when the device length under three different parameters is 4 mm,the Y-pol core mode is filtered out in three different mid-infrared spectral regions 2.75～5.50 μm,3.04～6.80 μm,and 3.66～7.80 μm,and the ultra bandwidth polarization filtering characteristics are obtained.(3)Using the dual-core MSF mode coupling theory,a dual-core MSF polarization beam splitter based on silica with air hole filled by liquid crystal is proposed and researched.The differences between filled liquid crystal and unfilled liquid crystal are compared and analyzed.The results show that when the splitter length(SL)is 94 μm,the X-pol and Y-pol light are separated into cores A and B within the wavelength of 1.352～1.701 μm and 1.579～1.647 μm,respectively.The splitting bandwidth of the cores A and B are 349 nm and 68 nm,respectively.A dual-core MSF polarization beam splitter based on chalcogenide glass Ge20Sb15Se65 with air hole filled by liquid crystal is proposed and researched,and its splitting characteristics in different wave bands is analyzed.The results show that when the SL is 7687 μm,the cores A and B obtain segmented polarization beam splitting characteristics in three different bandwidths,respectively.(4)Under the interaction between metal SPR effect and dual-core MSF mode coupling theory,a V-shape dual-core MSF polarization beam splitter based on silica with air hole coated by gold nano film is proposed and researched.The different mode coupling characteristics between the X-pol and Y-pol even mode and odd mode and second-order SPP mode are analyzed.The results show that when the SL is 192 μm,the splitting bandwidth of the cores A and B is 288 nm and 225 nm,respectively.A simple structure dual-core MSF polarization beam splitter based on silica with air hole coated by gold nano film is proposed and researched,and its splitting characteristics under two different parameters are analyzed.The results show that when the SL is 176 μm and 232 μm,the total polarization beam splitting bandwidth of cores A and B is 475 nm(1.232～1.707 μm)and 443 nm(1.249～1.692 μm),respectively,which can cover all optical fiber communication bands.Finally,a dual-core MSF polarization beam splitter based on silicon with air hole coated by gold nano film is proposed and researched.The results show that when the SL is 192 μm,the X-pol and Y-pol light are separated into cores A and B in mid-infrared spectral regions of 3.40～4.23 μm and 3.43～4.16 μm,respectively,and an ultra bandwidth polarization beam splitting characteristics are obtained.The research results of this paper include a variety of high performance new MSF devices,which solve the current key problems,provide a theoretical basis for optical fiber hybrid integration technology and provide core technology and key device support for the construction of all optical fiber network.It can not only drive and practice the major strategic needs of national development and actively promote the sustainable innovation and development of the country to an intelligent society.