A high-sensitivity fiber-optic F–P hydraulic pressure sensor based on a corrugated diaphragm structure

Hydraulic pressure sensors are widely used in disaster monitoring, chemical smelting, petroleum exploration, and biomedicine. In order to solve the problem of low sensitivity of the current optical fiber hydraulic pressure sensor, a high-sensitivity optical fiber Fabry-Perot (F-P) hydraulic pressure sensor with corrugated diaphragm structure was proposed. The sensor uses a corrugated diaphragm as a sensitive element; the F-P cavity is formed by the end face of the optical fiber and the smooth surface of the corrugated diaphragm; and the performance of the hydraulic pressure sensor is tested by the micro-pressure sensing test system. The results show that the sensor can measure pressure in the range of 0-0.12 MPa, with a sensitivity of 874.74 μm/MPa and a hysteresis error of 0.1%. The good consistency of the sensor has been verified through downhole tests. The research results provide a reference for the development of high-sensitivity optical fiber hydraulic pressure sensors.