Gas pressure sensor based on Fabry-Perot interferometer composed of quartz capillary

A novel gas pressure sensor based on Fabry-Perot interferometer is proposed and experimentally demonstrated. The sensor is fabricated by splicing the single-mode fiber onto a short length quartz capillary and coating a Polyimide film on the end-face of the quartz capillary. The total length of the sensor head is less than 60μm, compact structure which can be used flexibly in limited space and harsh environment. The experimental results show that the proposed sensor can detect the environment gas pressure by demodulating the wavelength drift of the reflection spectrum of the sensor. The maximum gas pressure sensitivity is 5.357nm/MPa, the linearity is 98.48% and the gas pressure measurement range is 0~0.3MPa. The sensor has the temperature sensitivity at low temperature, and it is insensitive to high temperature. Thus, the temperature cross-sensitivity can be ignored under the high-temperature conditions. The proposed sensor shows some advantages of compact size, high sensitivity, fast response time and low temperature cross-sensitivity, and it has a certain practical application value in industrial production and daily life.