Fiber-Optic Vector Magnetic Field Sensor Based on Mode Interference and Magnetic Fluid in a Two-Channel Tapered Structure

He Tian,Yanzeng Li,Yuxiao Song,Hanyang Li

doi:10.1109/jphot.2019.2944931

He Tian, Yanzeng Li + Show 2 more

Open Access

https://doi.org/10.1109/jphot.2019.2944931

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Abstract

An innovative approach to high-sensitivity simultaneous intensity and direction measurement in a two-channel tapered sensor is proposed and demonstrated. The sensor is comprised of magnetic fluid (MF)- filled micro-capillary and two accompanying micro-fiber, thus enabling evanescent interaction to take place between the optical mode in the capillary and MF. Given the magnetic nanoparticles (MNPs) of MF manifest anisotropic magnetic field. Experimental and numerical simulations were performed simultaneously, which provided a better understanding of the interaction between light and MF in addition to clarifying the dynamic process of MNPs within MF with the assistance of varying magnetic field. The experimental results are well consistent with the numerical simulation results and show that the sensitivity of this sensor reaches up to 244 pm/mT, with the direction error being merely ±1.4°. Therefore, the proposed sensor exhibits a unique sensitivity for the measurement of magnetic field intensity and direction in 3D space, which makes it best suitable for applications in transportation, medicine, and smart device.

Highlights

Magnetic field sensor is extensively applicable to various industries or purposes such as aerospace, environmental monitoring, navigation, energy survey and so on [1]
Among a wide range of functional materials, the magnetic fluid (MF), consisting of colloidal magnetic nanoparticles and surfactants interspersed in a suitable carrier liquid, is a special magnetic material with liquid fluidity which has been commonly used in magnetic field measurements [6]
We report an all-fiber vector magnetic field sensor with two optical transmission channels based on interference detection

Summary

Introduction

Magnetic field sensor is extensively applicable to various industries or purposes such as aerospace, environmental monitoring, navigation, energy survey and so on [1]. SPR-based devices typically require a vacuum coating process, and the material and thickness of the coating layer are important factors to be considered Another proposed optical fiber vector magnetometer was fabricated by fully injecting MF into the micro-channels array of the doublecladding PCF [26]. Compared to the other MF-based optical fiber magnetic field sensors this magnetometer has some inherent advantages in well robustness and orientation determinations. Both the injection of MF and the fusion of PCF, with the requirement of precise control, raise manufacturing complexity and fabrication cost. We report an all-fiber vector magnetic field sensor with two optical transmission channels based on interference detection. Compared with the previous works in magnetic field detection, we have achieved a breakthrough in extending the performance of magnetic field sensors from 2D planar to 3D space

Observation of the Distribution of Nanoparticles in the Capillary

Fabrication and Sensing Principle

Experiment and Discussion

Conclusions