title: A Magnetic Field Sensor Based on a Magnetic Fluid-Filled FP-FBG Structure.
abstract: Based on the characteristic magnetic-controlled refractive index property, in this paper, a magnetic fluid is used as a sensitive medium to detect the magnetic field in the fiber optic Fabry-Perot (FP) cavity. The temperature compensation in fiber Fabry-Perot magnetic sensor is demonstrated and achieved. The refractive index of the magnetic fluid varies with the applied magnetic field and external temperature, and a cross-sensitivity effect of the temperature and magnetic field occurs in the Fabry-Perot magnetic sensor and the accuracy of magnetic field measurements is affected by the thermal effect. In order to overcome this problem, we propose a modified sensor structure. With a fiber Bragg grating (FBG) written in the insert fiber end of the Fabry-Perot cavity, the FBG acts as a temperature compensation unit for the magnetic field measurement and it provides an effective solution to the cross-sensitivity effect. The experimental results show that the sensitivity of magnetic field detection improves from 0.23 nm/mT to 0.53 nm/mT, and the magnetic field measurement resolution finally reaches 37.7 T. The temperature-compensated FP-FBG magnetic sensor has obvious advantages of small volume and high sensitivity, and it has a good prospect in applications in the power industry and national defense technology areas.
authors.affiliation: Academy of Ocean Science and Engineering &amp; College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073, China. blovexiaji@163.com.
authors.forename: Ji
authors.initials: J
authors.lastname: Xia
authors.affiliation: Academy of Ocean Science and Engineering &amp; College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073, China. fuyin_wang@126.com.
authors.forename: Fuyin
authors.initials: F
authors.lastname: Wang
authors.affiliation: Academy of Ocean Science and Engineering &amp; College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073, China. luohongrong2000@163.com.
authors.forename: Hong
authors.initials: H
authors.lastname: Luo
authors.affiliation: College of Information Science and Engineering, Northeastern University, Shenyang 110819, China. wangqi@ise.neu.edu.cn.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Academy of Ocean Science and Engineering &amp; College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073, China. nudtxsd@163.com.
authors.forename: Shuidong
authors.initials: S
authors.lastname: Xiong
keywords: Fabry-Perot Cavity; Fiber Bragg Grating; magnetic field sensor; magnetic fluid; temperature compensation