Research On Distributed Microbending Optical Fiber Sensor Measurement System Based On OTDR

Modern optical fiber sensors owe their rapid development to the achievements of technologies in fabrication and communication. The Optical Time Domain Reflectometer(OTDR) is the preferred instrument for characterizing optical fibers especially in Optical Fiber Communication (OFC) system. OTDR complements attenuation measurements by measuring the backscattering. This permits not only the attenuation of the complete fiber to be measured, but also different attenuation coefficients of fiber segments, as well as optical losses in connectors and splices. Furthermore, it indicates the location of such optical losses as well as the length of the fiber.The optical fiber sensors based in OTDR have many advantages over traditional sensor, such as high sensitivity, immune to influence of electromagnetic field, corrosion resistant, simple structure etc. Loss theories of bending optical fiber, microbending modulation mechanism, optical fiber displacement sensors are researched in this dissertation.The main contents of this dissertation are as following:Firstly, microbend-induced loss theories and optical fiber microbending modulation mechanism has been researched.Secondly, the principle of OTDR and its important parameters are discussed. Experiments are took over periodic and non-periodic microbending modulation mechanism with single mode optical fiber using OTDR.Thirdly, distributed optical fiber displacement sensors based in OTDR and OTDR remote control system are designed.