Optical fiber ocean bottom vector magnetometer array

An optical fiber ocean bottom vector magnetometer (OOBVM) array based on fiber laser sensing technology is proposed. The fiber laser is modulated at the natural frequency of the sensing structure by the Ampere force in the magnetic field. In this way, the sensitivity is enhanced and the effect of power fluctuation of fiber laser is eliminated. The test result shows that its magnetic field resolution is about 0.86 nT / √ Hz@100 mA. The design and assembly process of the OOBVM array are demonstrated. A field test in South China Sea demonstrated that the OOBVM array can detect the movement of ferromagnetic objects in water, which implies the potential for applications in underwater object detection and marine geophysics.