Sensor Study On Extrinsic Fiber Faber Sensor And Its Demodulation

In recent years,fiber optic sensors have been developed and applied in many fields due to their advantages of good insulation,high sensitivity and free from electromagnetic interference.Among all kinds of optical fiber sensors,non-intrinsic faber sensor is widely used in optical fiber sensing field because of its simple structure,small size and wide wavelength range.At present,non-intrinsic faber sensor has become the research hotspot of sensor technology at home and abroad.In this paper,the extrinsic fiber optic sensor and its demodulation are studied in depth.Firstly,the research status of fiber optic sensor is briefly described,and its classification and application status are introduced.Then the interference principle,pressure sensing mechanism and temperature sensing mechanism of EFPI fiber sensor are analyzed.The solution to EFPI The tuning method is described in detail.The structure and force simulation of the EFPI sensor are proposed by Comsol software.The simulation results show that the load applied to the EFPI fiber sensor is the most stressed,and the strain sensitivity of the peak to pressure under different loads will be Changes have occurred;secondly,the preparation and demodulation experiments of EFPI fiber sensors are highlighted.The fabrication process of the traditional EFPI fiber sensor is described and the interference spectrum is quadraticly drawn by Matlab.The Matlab function is used to perform extreme value judgment and multi-peak method for cavity length demodulation.The Grabbs criterion is used to eliminate the error cavity length.The lateral load characteristics of the EFPI sensor are studied by pressure loading experiments.The experimental results show that the cavity length of the EFPI fiber sensor increases with the increase of pressure,and the growth is consistent with the simulation results.Finally,the EFPI/FBG series multiplexing structure is proposed.Analyze the multiplexing principle and perform the multiplexing sensing experiment to verify that the EFPI/FBG series multiplexed sensor can measure temperature and strain simultaneously and realize temperature self-compensation.