The Research On Fabrication,Performance Test And Influence Factors Of Chalcogenide Glass Fiber Connectors

Chalcogenide glasses（Ch Gs）are materials which contain one or more of chemical elements such as sulfur（S）,selenium（Se）,tellurium（Te）and some other metal elements（Ge,As,Sb,etc.）.They have recently attracted extensive attention in the field of infrared（IR）laser guiding,fiber sensing and medical detection,owing to their low phonon energy and wide IR transparency.Meanwhile,the chalcogenide glass fibers are widely used in Raman laser,supercontinuum generation sources and Brillouin fiber laser because of its high non-linearity coefficient(n2=2²0×10^-18 m²/W).However,compared with silica optical fibers,the chalcogenide glass optical fibers have a lower melting temperature and a lower mechanical strength,how to connect with other fibers becomes a ky problem in applications.Therefore,optical fiber connector as the most typical optical passive devices in the optical fiber communication system has the advantages of convenient docking,high flexibility and strong reliability,it can solve the technical problems that connect chalcogenide glass fiber with the same fiber or other fibers as an excellent candidate.Although some commercial companies in the world can provide some chalcogenide glass fiber connector products,there are few technical reports about fabrication and polishing for chalcogenide glass fiber connectors,the structure of this paper as follows:Based on the technology and reports of preparation and polishing of silica optical fiber connectors,the research on fabrication,polishing,performance test（insertion loss and return loss）and influence factors of chalcogenide glass fiber connector are presented in the thesis.The first chapter briefly introduces the research significance of this topic,summarizes the development of optical fiber connectors and the performance characteristics of chalcogenide glass fibers,and lists the related achievements of scholars at home and abroad.A brief review of the research progress of chalcogenide glass fiber connector is also elaborated.In the second chapter,the preparation of As₂S₃ glass fiber and its connector are investigated.Firstly,bulk glasses arsenic sulfide were prepared by the melt-quenching technique and then As₂S₃-As₃₈S₆₂ single-mode optical fiber was prepared using a co-extrusion process with a cladding diameter of approximately 240 μm and core diameter of 9.8 μm,also its related properties（hardness,infrared transmission characteristics,refractive index,loss,etc.）were characterized.Finally,a As₂S₃ fiber connector with about 1 m pigtail was successfully fabricated.In the third chapter,the influence factors of chalcogenide glass fiber connector are discussed.The optical performance in terms of insertion loss and return loss is briefly introduced.Through building the theoretical models,the key factors affecting insertion loss and return loss are discussed in detail,including mode field mismatch,end face gap,end face angle,fiber end face roughness,lateral offset and the metamorphic layer.The shape parameters of the zirconia ceramic（vertex offset,radius of curvature and fiber height）are also summarized,and its influence on the physical contact of chalcogenide fiber connector is briefly discussed.In the fourth chapter,the researches on the grinding and polishing process of As₂S₃ optical fiber connector are studied.Based on the technology and reports of preparation and polishing of silica optical fiber connectors,the end face grinding and polishing experimental processes of the chalcogenide fiber connector are designed.Finally,a set of optimized grinding and polishing parameters of chalcogenide fiber connector is recommended.The fifth chapter mainly illustrates the performance parameter test of As₂S₃ optical fiber connector,including end face roughness,the shape parameters of the zirconia ceramic,insertion loss,return loss and the repeatability of insertion loss,and analyses the test results briefly.The last part is a summary of the work,which points out the shortcomings of the experiment and hopes to be solved in the future,then proposes the application prospects of chalcogenide optical fiber connectors.