Research On Fiber Bragg Grating Demodulation Based On LabVIEW

With the rapid development of optical fiber communication technology,optical fiber sensing technology has been studied in recent years.People have more and more requirements for the information acquisition and data processing technology,the traditional sensor can not meet the demand,thus the optical fiber sensor arises at the historic moment.Because of its high sensitivity and strong ability of anti electromagnetic interference,fiber Bragg grating sensors are becoming more and more dominant.LabVIEW is a graphical editing language programming software,it generates the frame form of the program,Lab VIEW is the core of the NI design platform,is also ideal for the development of measurement and control system.It can provide the appearance and practical application with the traditional instrument similar to controls(such as oscilloscope,waveform chart,etc.)can easily create a user interface(i.e.front panel),through the use of icons and connection control and edit on the front panel to realize the function of the.At the same time,LabVIEW is a flexible software to facilitate the creation of the required virtual instrument,its programming interface and the operation of the process of lively and interesting,it can also be an independent executable file,improve work efficiency.In this paper,using the coupled mode theory of fiber grating sensing mechanism,respectively describes Interferometric Demodulation System Based on non equilibrium M-Z waveguide modulator,and polarization maintaining fiber based on unbalanced M-Z interferometer demodulation scheme contrast wavelength demodulation precision,and combined with LabVIEW graphical programming software to design the data processing program for measurement and analysis of wavelength data demodulation system.The main work is as follows:(1)The research significance of fiber Bragg grating sensor and Lab VIEW is introduced.(2)The sensing principle of fiber Prague grating is analyzed,and the important application of LiNbO3 waveguide electro-optic modulator in this experiment is studied.(3)Improve the accuracy of fiber grating wavelength demodulation system.Due to the periodic cosine variation of the transmittance T and the wavelength lambda,the curve is approximately linear when the transmittance is approximately 0.5.By changing the modulation voltage of the lithium niobate waveguidemodulator,the wavelength of the demodulation can fall as far as possible in the linear demodulation range,thus greatly improving the precision of the demodulation wavelength.(4)The use of LabVIEW to establish a friendly interface software is introduced in the part of data acquisition module,program realization method and test results,and better applied to the demodulation system for data processing,obtained good results.