Research On The Technique And Application Of Long-distance Wavelength Division Multiplexing For Distributed Optical-fiber Sensors

Distributed optical fiber sensing technology(DOFS)is attractive for many industrial applications due to its superior performance.DOFS permits the measurement of a desired parameter as a function of length along the fiber.For this reason,DOFS becomes a research hotspot.However,with the rapid development of science and technology,the urgent requirements for the optical fiber sensing technology are ever-increasing proposed.A single DOFS may be unable to meet the requirements of integration,networking and long-distance in the future applications.A multiple DOFS system based on Dense Wavelength-Division Multiplexing(DWDM)is proposed in this thesis.DWDM allows information at various channels to be transmitted with different wavelengths and hence fully exploits the vast bandwidth provided by optical fiber.Firstly,this thesis introduces the background,construction and key technology of DWDM,and investigates the nonlinear effects that limit the performance of this multi-wavelength system.After that,to analyze nonlinearity phenomena in this multiple sensors system,theoretical simulations and experiments are used.For long-distance sensing performance,we use Erbium Doped Fiber Amplifiers and Raman amplifier to extend the sensing distance.And on this basis,we proposed a relay and magnifying system to enhance the operating range of DOFS.This system amplifies pump light and signal light respectively,which improves the efficiency and detecting-distance of DOFS.