Vector magnetic field sensor based on coreless D-shaped fiber and magnetic fluid

Area of Science:

• Photonics
• Fiber Optics
• Sensor Technology

Background:

• Fiber optic sensors offer advantages in harsh environments.
• Magnetic field sensing is crucial for various industrial and scientific applications.
• Ferrofluids exhibit tunable optical properties in response to magnetic fields.

Purpose of the Study:

• To propose and demonstrate a novel vector magnetic field sensor.
• To investigate the performance of a ferrofluid-encapsulated coreless D-shaped fiber.
• To explore the relationship between sensor geometry and magnetic field sensitivity.

Main Methods:

• Fabrication of a coreless D-shaped fiber using fiber polishing.
• Encapsulation of the D-shaped fiber with magnetic fluid.
• Utilizing multimode interference (MMI) for sensing.
• Analyzing the interaction of evanescent fields with the magnetic fluid.

Main Results:

• Achieved vector magnetic field sensing based on fiber geometry and magnetic fluid properties.
• Demonstrated enhanced sensitivity with reduced residual thickness (RT).
• Measured magnetic field intensity sensitivity up to -0.483 dB/mT at a RT of 42.7 µm.

Conclusions:

• The coreless D-shaped fiber sensor effectively measures vector magnetic fields.
• Sensor sensitivity is tunable by adjusting the residual thickness.
• The use of standard single-mode fiber (SMF) provides a cost-effective fabrication method.