A Study On Application Of EDFA In Distributed Optical Fiber Sensing System

Optical fiber is a complete link.The application of sensing technology is to measure the physical characteristics of optical fiber.Distributed sensing technology is very different from traditional point sensing technology.Optical fiber sensing technology realizes the distributed sensing scheme is to continuously measure the changes of the external physical parameters sensed in the entire optical fiber.The birth of undersea fiber optic cable was a few decades ago.At the same time,with the development of information technology,mankind has entered the5 G era.In the 5G era,the amount of information transmission increases,the distance of transmission becomes longer,and the signal transmission needs to be faster and more stable.Under the background of today's scientific and technological development,optical fiber sensing technology is developing more and more rapidly,playing an important role in aerospace,petrochemical,electric power,civil engineering and other fields.This kind of technology is a multi-disciplinary modern science and engineering technology.The sensor used in distributed optical fiber sensing technology is optical fiber.Distributed monitoring means that it can be implemented in the sensor laying network to realize the detection of each sensor.Each point can separately obtain,process,and provide data of various physical parameter information,and can realize feature classification to further improve the performance of the system.At this stage,in the research of long-distance fully distributed optical fiber sensing systems by researchers,an inevitable problem is that optical signals propagate information in optical fibers and attenuate as the distance increases.Then the use of optical amplifiers can effectively solve such problems.Erbium-doped fiber amplifier(EDFA)is an important component,which is indispensable for dense optical wave multiplexing(DWDM)systems and future high-speed systems and all-optical networks.EDFA has the advantages of high gain,low noise and flat gain.These advantages also directly promote EDFA to various optical fiber sensing systems and perform direct optical amplification to improve the performance of the sensing system.what's more,the minimum input power that EDFA can amplify directly determines the minimum detection intensity of the optical fiber sensing system.Its noise figure also determines the signal-to-noise ratio of the output signal.The progress of science and technology has further requirements for distributed optical fiber sensing technology,while the performance improvement and technological development of optical fiber sensing technology also play a further impetus to the research of EDFA.The main content of this article is divided into three parts:First,it introduces the scattering phenomenon of light propagating in the optical fiber,explains its principle and classification,and summarizes the theories of such cutting-edge technologies in the field of optical fiber sensing that use ?-OTDR for vibration monitoring.Analyze its development status and study the characteristics and influencing factors of the system in the specific application process.Secondly,the research of this thesis adopts the fully distributed optical fiber vibration sensing technology.It is hoped that the advantages of distributed optical fiber sensing can be fully utilized to analyze and discuss the research progress of distributed optical fiber sensing vibration monitoring system.At the same time,the system is aimed at designing and realizing the optimal EDFA structure and optimal parameters.Finally,this thesis analyzes the influence of several parameters on the characteristics of EDFA from a theoretical perspective,such as the structure of EDFA,the length of erbium-doped fiber,the power of pump light and the power of input signal light.This article has carried on the software simulation to EDFA.In order to optimize the performance of the EDFA in the distributed optical fiber sensing vibration monitoring system,the specific influencing factors of the input signal on the gain and noise of the EDFA are obtained.The noise figure of EDFA,the length of erbium fiber and the influence of the input signal on its overall performance are experimentally studied.The application research of the influence of EDFA on the signal waveform is carried out through experiments on the above-mentioned characteristic parameters.The actual performance is tested,and the specific design is made.It is suitable for erbium-doped fiber amplifier in distributed fiber-optic sensing vibration technology.