Research On Fiber-Optic Fabry-Perot High Pressure Sensor

Fiber Fabry-Perot pressure sensor has wide application prospect in deep sea pressure exploration and offshore oil and gas development because of its advantages of electrical insulation,corrosion resistance and good stability.Diaphragm-type fiber Fabry-Perot pressure sensor producted by micro-electromechanical technology and fiber Fabry-sensing technology,has high sensitivity,good consistency and can be mass production of a little bit.These advantages for its commercial production and largescale applications to create the conditions.In this paper,the research on the fiber-optic Fabry-Perot high pressure sensor is carried out to meet the requirement of precise pressure detection in deep sea high-pressure and harsh environment.The specific research contents of this paper include:1?The structure of the sensor chip,the sensor core and the sensor package are designed.The optical signal analysis model of optical fiber Fabry-Perot pressure sensor is studied.The white light interference sensing principle of the sensor is analyzed.The optical characteristics of single crystal silicon are introduced.2?The fixed boundary model,simply supported boundary model and finite element numerical calculation model of the single crystal silicon diaphragm in the sensor were studied,and the characteristics of the finite element model were analyzed.The effect of chip size parameters on the full-range variation of Fabry-Perot cavity is studied.The sensor chip size parameters of three different ranges are designed by finite element numerical calculation.3?The manufacturing process of the sensor chip and the fabrication method of the sensor are introduced.Pressure test system was built and the pressure test was carried out on the sensors 1 ~ 3.The experimental results show that the maximum range of the sensor is 105 MPa and the measurement accuracy is better than 0.100% F.S..It is found that the full-scale cavity length variation of the sensor chip agrees well with the finite element numerical results.The error of the full range cavity length can be reduced to less than 13.4% when we design sensor chips by the FEM model.