一种基于磁流体包覆锥形光纤的磁场传感器

A magnetic field sensor based on magneto-fluid-coated tapered fiber

为实现低成本、高灵敏度的磁场传感器,提出了一种基于磁流体包覆锥形光纤的磁场传感器,该传感结构为基于错位熔接单模光纤制成的马赫-曾德干涉仪。为了增强传感器对外界响应的灵敏度,使用氢氧火焰熔融拉锥方法对两个熔接点之间的单模光纤进行拉锥处理。将干涉仪包覆磁流体并用毛细管对其进行封装。由于磁流体具有磁光特性,透射光谱随外加磁场的变化而变化,通过监测透射光谱幅度的变化可以实现磁场传感。实验中获得的磁场响应灵敏度为0.599 dB·mT^(-1)。该光纤磁场传感器具有制作简单、结构紧凑和成本低等优点,有望应用于航空航天、地质勘探、生物医学等不同领域进行磁场测量。

To achieve a low-cost and high-sensitivity magnetic field sensor,a magnetic field sensor based on magnetic fluid-coated tapered optical fiber is proposed.The sensing structure is a Mach-Zehnder interferometer based on offset spliced single-mode optical fibers.In order to enhance sensitivity of the sensor to external responses,the hydrogen-oxygen flame fusion tapering method is used to taper the fiber between the two offset splicing points.The interferometer is coated with magnetic fluid and encapsulated with a capillary tube.Due to the magneto-optical properties of magnetic fluids,the transmission spectrum changes with the external magnetic field,magnetic field sensing can be realized by monitoring the amplitude of transmission spectrum.In the experiment,a magnetic field response sensitivity is 0.599 dB·mT^(-1).The optical fiber magnetic field sensor has the advantages of simple fabrication,compact structure,and low cost,and it is expected to be applied in different fields such as aerospace,geological exploration,and biomedicine for magnetic field measurement.