Highly Sensitive Air Pressure Sensor Based on Fabry-Perot Interference

A highly sensitive optical fiber air pressure sensor based on Fabry–Perot interferometer is proposed and demonstrated. The sensor is fabricated by flat-cut single-mode optical fiber, capillary glass tube, stainless steel sleeve, nylon substrate, and metal aluminum film. The finite element simulation was performed in two steps using the COMSOL Multiphysics software. In the first step, the structural mechanics module is used to simulate the deformation of the membrane under a fixed pressure, so as to obtain the corresponding sensor cavity lengths under different pressure. In the second step, the wave optics module is used to get the reflection spectrum of the sensor under different cavity lengths. Then the linear relationship between the reflection spectral shift of the sensor and the pressure is obtained. Thus, the average spectral sensitivity of the sensor under air pressure is −3.10335 nm/KPa. A metal-aluminum thin film F-P cavity sensor was fabricated for experimental verification. According to the experimental results, when the air pressure ranges from 0 Pa to 1000 Pa, the spectral sensitivity of the sensor is as high as −3.10 nm/KPa. This is almost consistent with the simulation result. The sensor has exhibited potential application in the fields of measurement of airway pressure and environmental monitoring.