A fiber-optic combined acoustic temperature and pressure sensor for ocean observation

In order to improve the integration of the detection system for underwater acoustic, temperature and pressure in the ocean, a novel fiber-optic combined underwater acoustic, temperature and pressure sensor is proposed. The fiber-optic combined sensor consists of a FBG temperature sensor, a FBG pressure sensor and a Michelson interferometric fiberoptic hydrophone, which are connected by a single optical fiber. The optical signals from the FBG sensors and the fiberoptic hydrophone are completely independent and do not affect each other, so they can be detected and demodulated simultaneously. The fiber-optic combined acoustic temperature and pressure sensor can also be used in combined sensor arrays by time division multiplexing and wavelength division multiplexing. The fiber-optic combined sensor is designed and fabricated, and the performance of the sensor is tested experimentally. The experimental results show that the fiberoptic combined sensor system can measure the underwater temperature and pressure, underwater acoustic signal accurately.