An optical fiber Fabry-Pérot micro-pressure sensor based on beam-membrane structure

In this paper, an optical fiber Fabry-Pérot (FP) sensor for micro-pressure measurement is proposed. The FP interferometric cavity is composed of an end face of the incident optical fiber and a sensitive silicon diaphragm. The sensitive silicon diaphragm creatively utilizes a beam-membrane structure which is fabricated by micro-electro-mechanical system manufacturing technology. The finite element method simulation results show that the beam-membrane structure can achieve higher sensitivity and better linearity. The sensor performance test platform is built by a ASE-wide spectrum light source, optical spectrum analyzer, micro-pressure gas source and so on. The phase demodulation method is employed to demodulate the cavity length signal from the spectrum. The measure range of the sensor is 0-10 KPa, and the experimental sensitivity of the cavity length can reach to 242 nm KPa^-1.