Fiber-Optic Vector Magnetic Field Sensors Based on Magnetic Fluid: Progress and Prospect

Recent developments of various types of fiber-optic vector magnetic field sensors based on magnetic fluid (MF) are reviewed. From the perspective of sensing principles, these sensors are classified into Mach-Zehnder interferometer (MZI) sensor, surface plasmon resonance (SPR) sensor, Fabry-Perot interferometer (FPI) sensor, fiber grating sensor, Sagnac interferometer (SI) sensor, and Michaelson interferometer (MI) sensor. The working mechanisms, fabrication methods, and performances of these sensors are discussed in detail. Finally, these sensors are compared and analyzed from measurement range, sensitivity, mechanical strength, and so on. Some current common problems and prospects for further development are pointed out. Furthermore, this work gives some suggestions to improve the sensitivity and mechanical strength, which can also be applied in fields such as biomedical testing and undersea environmental monitoring where measurement accuracy and mechanical strength are both required.