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Research Optical Fiber Magnetic Sensing Of Stability Michelson Interferometer

Posted on:2018-04-01Degree:MasterType:Thesis
Country:ChinaCandidate:J P LiFull Text:PDF
GTID:2428330566451511Subject:Software engineering
Abstract/Summary:PDF Full Text Request
Magnetic sensing technology is widely used in the information industry.Compared with traditional magnetic sensing technologies,the interferometric fiber optic magnetic sensing technology has the characteristic of high sensitivity.In this paper,the research status and development trend of fiber optic magnetic sensing technology are investigated and summarized.On this basis,the structure and overall design scheme of Michelson interferometric fiber optic magnetic sensing system are proposed.In this paper,the phase change of the interferometric fiber-optic magnetic sensor is mainly derived from the change of the length of the fiber,while the influence of the fiber diameter and the refractive index of the fiber is small.The effect of applied stress on the magnetostrictive effect is also analyzed and it is known that if tensile stress is applied to the positive magnetostrictive material,this will result in anisotropy reduction and simultaneous magnetization.And the influence of magnetic field direction on the magnetostrictive effect is analyzed.It is found that the transverse magnetic field does not produce longitudinal magnetostriction.Therefore,the direction of the magnetic field is required to be consistent with the length of the material during the testing.Through the COMSOL simulation software,it is found that the magnetostrictive effect is best when the magnetic field direction is perpendicular to the axial direction.Based on the simulation results and the actual situation,the parameters of the magnetostrictive material are as follows: the radius of the cylinder is 3cm,the height is 2cm,the thickness is 0.2mm,fiber turn of the tube is 53(10m).And the magnetic sensor simulation analysis found that the sensor can produce0.25?rad phase difference.Based on the above analysis,the optical fiber magnetic sensing system based on Michelson interferometer is established.The two problems of stability are polarization fading and phase shift.Finally,through analysis of the polarization fading and phase shift in this paper,the Faraday rotation mirror method is applied to reduce the interference signal polarization fading,which is characterized by a Faraday rotating mirror in front of the mirror;the phase carrier cross-multiplication algorithm is applied to solve the phase shift problem and to realize the demodulation of the interference signal.In this paper,the algorithm is realized byLabVIEW software.Through the simulation analysis of the algorithm,it is found that the algorithm can demodulate the signal,and has a certain anti-noise ability.At last,the results show that the minimum signal frequency that the magnetic sensor system can detect is 20 Hz and the minimum magnetic signal is between 80 nT and 100 nT.
Keywords/Search Tags:Michelson interferometer, optical fiber magnetic sensing, COMSOL multiphysics simulation, phase carrier algorithm
PDF Full Text Request
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