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Research Of Fiber Sensor Based On Fiber Grating Cascading Mach-zehnder Interferometer

Posted on:2018-03-26Degree:MasterType:Thesis
Country:ChinaCandidate:M L XiongFull Text:PDF
GTID:2428330542484241Subject:Optical Engineering
Abstract/Summary:PDF Full Text Request
Recently,the sensor based on optical fiber grating,and the sensor based on Mach-zehnder interferometer?M-ZI?are increasingly popular in the field of optical fiber sensing,due to its small size,high sensitivity and exquisite.This main work of this paper is research their theory,fabricate and applications of the sensor which based on fiber gratings cascaded with Mach-zehnder interference structures,and discuss various physical parameters in sensing area.The details are arrange as following:1.Propose a fiber M-ZI sensor which based on LPFG and spherical-shape structures,introduce the fabricate method,and analysis the FFT frequency feature.Measure the temperature,liquid level and curvature,observe the wavelength shift according to the transmission spectrum.After linear fitting,realize simultaneous measurement of liquid level and temperature,and large range curvature measurement,meanwhile discuss the long-period fiber grating position influence to the sensor sensitivity.2.Fabricate fiber sensor including MMF,spherical-shape structure and FBG,MMF can excite the cladding modes and on the spherical-shape structure,the cladding modes can be combined into the core and interfere with core mode.Because of the exist of FBG,introducing sensitivity matrix and realize simultaneous measurement of refractive index and temperature.3.Introduce a fiber M-ZI sensor,which based on spherical-shape structure and a taper,the taper is write by CO2.Higher cladding modes can be excite in the taper structure,and couple with core mode in the spherical-shape structure.Tested the longitudinal micro displacement and temperature response?...
Keywords/Search Tags:Mach-Zehnder interferometer, Bragg fiber grating, Long period fiber grating, Liquid level, Curvature, Temperature, Simultaneous measurement
PDF Full Text Request
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