Fabrication And Reseach On The High Temperature And Pressure Optical Fiber Sensor

Pressure measurement under high-temperature is one of the key techniques required by many important areas(such as oil well logging of energy area, etc.), and also has been a long-term problem of testing technology.It provid a very possible method for the precision test of high temperature and pressure in this thesis, which solve this hard problem through micro-cavities achieved by the employment of 157 nm DUV laser. The main contents and results of this study are presented below:(1) Firstly, a fiber Fabry-Perot pressure sensor with cascaded cavities is designed in this study, which can provide a viable solution for dual-parameters measurements of high-temperature and pressure. The pressure sensor structure is manufactured by 157 nm laser–micromaching, then the theoretical analysis and experimental testing of the parameters characteristic of this sensor are accomplished, finally the experments results successfully illustrated that the sensor can achieve the simultaneous measurement of temperature and pressure. When pressure is applied on the sensor, optical path difference of the sensor show high linearly as well as stability, with temperature range from 25℃ to 400℃,which shows the sensor with such a sturture can be a useful solution of pressure measurement under high-temperature.(2) As the photonic crystal fiber(PCF) is made of pure silica, firstly a novel structure is designed on the photonic crystal fiber to get the fiber Fabry-Perot pressure sensor in this study, the sensor stucture is achieved by 157 nm laser, then temperature and pressure characteristics exploration are finished in the experments. The experimental results show that the spectral wavelength shift has a good linearly and reliably when pressure apllied on the sensor, with the temperature range of 25℃ to 700℃, the results also reveal a fact that this sensor has a emperature compensation mechanism(the cavity length can remain stable under the variation of temperature, with a natural thermal-insensitivity), which can overcome the temperature drift problem in sophisticated high-temperature tests.Two fiber Fabry-Perot pressure sensors with different materials are designed in this study, then innovation of the sensor structures( micro-composite fiber interferometer waveguide structure), craft production, characteristics testing are also researched, it is found that both of the two sensors with all-fiber integrated structure can be well applied in pressure measurement under high-temperatures, with advantages of high linearity, stability, anti-electromagnetic interference, corrosion resistance, small size for easy installation, and so on.