Analysis & Measurement Of Bend Insensitive Fiber And The Application In FTTH

The main object of this dissertation is to provide an appropriate FTTH optical network solution, solve the large insertion loss caused by small radius bend, and upgrade the totoal performance of FTTH optical nework.In first chapter, analyze the development of FTTH technology and the market trend of FTTH, optical fiber development at FTTH application and main factories influenced the FTTH performance, get the conclusion that bend insertion loss is the main factory of FTTH performance.In second chapter, analyze the bend insertion loss through physical essence, radial analysis and electromagnetic theory, get the expression of bend insertion loss, and get the conclusion that relative refractive index difference, radis of core and modal field diameter is the main factory of bend insertion loss.In third chapter, according to ITU-T G.657-- Characteristics of a Bending Loss Insensitive Single Mode Optical Fibers and Cables for the Access Network, test the bend insensitive fiber performance with the G.657A and G.657B standard. There are five bend insensitive fibers: small mode field diameter fiber, trenched cladding fiber, hole-assisted fiber (HAF), photonic crystal fiber (PCF) and nanostructure fiber. Small mode field diameter fiber and trenched cladding fiber is much easy for produce, but it is not matching with standard singlemode fiber. Trenched cladding fiber is limited of its bending capability. Hole-assisted fiber and photonic crystal fiber have very good bending performance, but it is dismatching with standard singlemode fiber, and it is very difficult for produce. Nanostructure fiber uses nanostructure technology. The process is easy and can be mass production, and the performance of bend insertion loss is 100 time of G.652D, 10 time of G.657B. In additional, nanostructure fiber is complied with G.652D,G.657A and G.657B, it is the best selection for FTTH deployment.In fourth chapter, according to the FTTH system frame of passive optical network, analyze the application in a trial project, including the application of central office, fiber distribution house(FDH), distribution cable, fiber distribution terminal(FDT), drop cable, mechincal connector and faceplate. Test the insertion loss of the link, throughput, latency and frameloss rate over the optical network. It is proven that using bend insensitive fiber in the FTTH application, can settle the technical problem of FTTH network in the business building and apartment.Durning the deployment of FTTH, the reliability analysis to bend insensitive fiber when it has small bending, even the radius is 5mm, the failure rate is still low than 10ppm. Compared with other fault, it can almost be ignored.In fifth chapter, it is the summary of this dissertation and the expectation of an nanostructure multimode fiber, which is used in fiber to the desk (FTTD).