Measurement research of the optical fiber vector hydrophone used in underwater acoustic applications in the deep ocean

This paper reports a resonant type optical fiber vector hydrophone (OFVH) for deep-sea applications, which is composed of a three-component optical fiber accelerometer and an optical fiber pressure hydrophone. To meet the acoustic requirements in the deep-sea, the orthogonal and unitized structure of the three-component accelerometer is adopted to increase the sensitivity and the operating frequency band of the accelerometer. The results show that the acceleration sensitivity is about 40dB re rad/g and the pressure sensitivity is nearly -147 dB re rad/μPa. The fluctuations of the acceleration and pressure sensitivity are less than 1.5dB over the 10-2000Hz frequency range. The deep-sea trial verified its excellent acoustic detection performance. Both the direction-of-arrival (DOA) and range for distant ship is estimated. The DOA estimation error is no higher than 10° and the range estimation error is less than 10%. This OFVH has a wide application prospect in the deep-sea.