Studying Distributed Optical Fiber Perimeter And Its Location Technology Based On Dual Mach-Zehnder

With the economic development,social progress,people's awareness of security is growing.At the same time,criminals used by criminals are also more complex and intelligent.The traditional perimeter security means more and more difficult because of their own limitations to meet people's lives and property security needs.Based on distributed optical fiber sensor,perimeter security system has become a research hotspot with its high response,high accuracy and high positioning precision.This paper mainly discusses the principle,structure and implementation of perimeter security system based on dual Mach-Zehnder interferometer,and builds the actual security system with LabVIEW software program,aiming to contribute to the industrialization of distributed optical fiber perimeter security system power.The main results are:1.Through the collection,collation of a large number of documents and books,a simple understanding of the development of interferometric fiber optic sensing technology and the status quo and several of the more common types of interferometric fiber optic sensors,and focus on learning Mach-Zehnder interferometer modulation principle,Orthogonal operating state principle and phase demodulation based on 2 × 2 coupler and 3×3 coupler.2.Based on the theory of system learning and the structure of Mach-Zehnder interferometer,a perimeter security system based on double Mach-Zehnder interferometer is proposed.The structure of the system and the principle and implementation of the perturbation localization are introduced in detail.And the factors that affect the system stability and positioning accuracy are analyzed.3.In order to verify the feasibility of the proposed perimeter security system,the system uses the LabVIEW development platform to learn the use and characteristics,and the use of LabVIEW development platform to develop a simulation module:orthogonal bias working state simulation module,based on 2 Phase demodulation simulation module based on 3 x 3 coupler,phase demodulation simulation module based on 3 × 3 coupler and cross-correlation function positioning simulation module.Through the simulation analysis,the feasibility of the system is verified.4.Based on the simulation analysis,the actual perimeter security system is set up and the user interface and data processing module of the LabVIEW development platform are set up.The false alarm rate and positioning accuracy of the 20km long perimeter security experiment are analyzed..Through the analysis of the experimental data,the false alarm rate of the system is only 1%,and the absolute positioning error under the 20km sensing distance is 46.04m.Which can be used for engineering application.5.Finally,the advantages and disadvantages of the proposed perimeter security system are summarized,and the future work is prospected.