Fiber Optic Fabry-Perot Magnetic Field Sensor With Temperature Compensation Using a Fiber Bragg Grating

Based on the characteristic of magnetic-controlled refractive index, magnetic fluid was used as a sensitive medium in fiber optic Fabry-Perot (F-P) cavity. Combined with the temperature sensing property of fiber Bragg grating (FBG), a novel fiber optic F-P magnetic field sensor with temperature compensation was proposed. The sensor probe has the advantages of simple structure, low cost, and high magnetic field measurement accuracy. Magnetic field and temperature can be simultaneously measured by the proposed sensor. Sensing mechanism and experimental results indicated that the temperature cross effect on magnetic field measurement can be effectively compensated using a FBG. The maximal magnetic field intensity is up to 600 Gs with a sensitivity of 0.04 nm/Gs and measurement resolution is 0.5 Gs.