Research On Signal Qualify And Stability Of Optical Fiber Fabry-perot Pressure Sensor

Optical fiber Fabry-Perot(F-P)sensor has been widely used in aerospace,petrochemical,energy and construction of lilitary and industrial fields at present.Optical fiber F-P sensor combining optical fiber technology and Micro-electro Mechanical Systems(MEMS)technology can meet the requirements of measurement accuracy and stability of sensor in harsh environments,due to the advantages of small size,anti-electromagnetic interference ability of outstanding,corrosion resisting,high sensitivity,adaptability in harsh environments,good consistency and batch production and so on.Optical fiber F-P sensor now receives abroad attention and research.For high accuracy and high stability of pressure sensing requirements,the paper carried out the research on signal quality and stability of optical fiber F-P sensor.In the paper,specific research contents include:1?Beam transmission model of sensor head chip of optical fiber F-P sensor was researched,to analysis the relations between interference fringe intensity& contrast and the thickness of sensor head &reflectivity,to achieve optimum sensor signal quality.Elastic-optic mechanical properties model of sensor diaphgram deformation was established.The influence of size parameters of sensor head chip on silicon diaphragm deformation was analyzed.Bonding mechanism and bonding process of sensor head chip of optical fiber F-P sensor was analyzed and introduced.2?Evaluation index of signal quality of optical fiber pressure sensor was studied.The influence of signal-to-noise ratio(SNR)on interference jump and absolute phase of pressure sensing demodulation was theoretical simulated.Experiment test system of optical fiber F-P pressure sensing was built.Experiment about the influence of SNR on pressure measuring is carried out.The influence of pressure demodulation accuracy under different values of SNR was experimentally studied.Experimental results were consisted with theoretical analysis.3?Stability influence mechanism and aging methods of optical fiber F-P sensor were researched.Residual air pressure and heat stress of sensor on deformation of diaphgram was theoretically analyzed.Research on methods of temperature aging,pressure aging and composite aging of optical fiber F-P sensor was carried out.The influence of aging process on stability of optical fiber F-P sensor was experimentally discussed,in order to achieve high accuracy and high stability of optical fiber F-P pressure sensing.