Perth College, University of Highlands and Islands, Perth PH1 2NX, UK.
Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne NE1 8ST, UK.
Sensors (Basel). 2022 Nov 5;22(21):8536. doi: 10.3390/s22218536.
In this paper, a high-sensitivity magnetic field sensor based on a single-mode-tapered small-core-single-mode (STSCS) optical fibre structure is investigated. The tapered small-core section of STSCS is surrounded by magnetic fluid (MF) containing ferromagnetic particles (FMPs) of different concentrations. The FMPs align themselves along the magnetic field, depending on the strength of the magnetic field. This alignment of FMPs changes the refractive index around the tapered small-core section, which in turn changes the output spectral response of the STSCS optical fibre structure. The change in spectral response is then calibrated for sensing the magnetic field strength. This paper also investigates the effect of both the taper waist diameter of the STSCS optical fibre structure and the concentration of MF surrounding it on the magnetic field sensitivity. The maximum sensitivity demonstrated in this paper is 0.46 nm/mT for a taper waist diameter of 10 μm surrounded by 1.22% FMPs in the MF. The magnetic sensor demonstrates reversible results, and its effects on the orientation of the magnetic field along the X-Y, X-Z and Y-Z axes are also investigated, which suggest that the sensor is capable of vector magnetic field measurement.
本文研究了一种基于单模锥形小芯单模（STSCS）光纤结构的高灵敏度磁场传感器。STSCS 的锥形小芯部分被含有不同浓度铁磁粒子（FMP）的磁性液体（MF）包围。FMPs 会根据磁场的强度沿着磁场排列。这种 FMPs 的排列方式改变了锥形小芯部分周围的折射率，从而改变了 STSCS 光纤结构的输出光谱响应。然后，通过校准光谱响应来感测磁场强度。本文还研究了 STSCS 光纤结构的锥形腰直径和周围 MF 的浓度对磁场灵敏度的影响。本文最大灵敏度为 0.46nm/mT，在 10μm 的锥形腰直径下，周围 MF 中含有 1.22%的 FMPs。该磁传感器表现出可逆的结果，并且还研究了其对 X-Y、X-Z 和 Y-Z 轴上磁场方向的影响，这表明该传感器能够进行矢量磁场测量。
