Magnetic Field Sensing Using Tapered Small-Core Optical Fibre Surrounded by Different Concentrations of Magnetic...

Area of Science:

• Optoelectronics
• Nanotechnology
• Sensor Technology

Background:

• Magnetic field sensing is crucial for various applications.
• Optical fiber sensors offer advantages like immunity to electromagnetic interference.
• Developing high-sensitivity and vector-capable magnetic field sensors remains an active research area.

Purpose of the Study:

• To investigate a high-sensitivity magnetic field sensor based on a single-mode-tapered small-core-single-mode (STSCS) optical fiber structure.
• To explore the influence of magnetic fluid (MF) concentration and taper waist diameter on sensor performance.
• To assess the sensor's capability for vector magnetic field measurement.

Main Methods:

• Fabrication of an STSCS optical fiber structure.
• Coating the tapered section with magnetic fluid (MF) containing ferromagnetic particles (FMPs).
• Analyzing the change in output spectral response of the optical fiber sensor under varying magnetic field strengths and orientations.
• Calibrating the spectral shift to determine magnetic field strength and direction.

Main Results:

• A maximum sensitivity of 0.46 nm/mT was achieved with a 10 μm taper waist diameter and 1.22% FMP concentration in MF.
• The sensor demonstrated reversible responses, indicating reliable performance.
• The sensor successfully measured magnetic field orientation along the X-Y, X-Z, and Y-Z axes, confirming vector sensing capability.

Conclusions:

• The developed STSCS optical fiber sensor offers a promising approach for high-sensitivity magnetic field detection.
• The sensor's ability to perform vector magnetic field measurements enhances its utility in complex environments.
• Further optimization of MF concentration and fiber taper parameters can potentially lead to even higher sensitivities.