Optical fiber magnetic field sensor based on single-mode-multimode-single-mode structure and magnetic fluid

Area of Science:

• Photonics and Sensing
• Magnetometry
• Fiber Optics

Background:

• Magnetic field sensing is crucial in numerous scientific and industrial applications.
• Existing magnetic field sensors face limitations in sensitivity, size, or operating environment.
• Optical fiber sensors offer advantages like immunity to electromagnetic interference and remote sensing capabilities.

Purpose of the Study:

• To propose and demonstrate a novel all-fiber magnetic field sensor.
• To investigate the performance and sensitivity of the proposed sensor design.
• To develop a theoretical model and conduct numerical simulations for device optimization.

Main Methods:

• Fabrication of a single-mode-multimode-single-mode (SMS) fiber structure.
• Integration of a no-core fiber as the multimode waveguide.
• Encapsulation of magnetic fluid (MF) within a capillary tube to act as the magnetic sensitive medium.
• Characterization of the sensor's response to magnetic fields by measuring transmission spectrum shifts and loss variations.

Main Results:

• Successful fabrication of an all-fiber magnetic field sensor.
• Achieved high sensitivities of up to 905 pm/mT for wavelength shift and 0.748 dB/mT for transmission loss.
• Developed a theoretical model and performed numerical simulations validating the sensor's performance.

Conclusions:

• The proposed SMS fiber structure with magnetic fluid is an effective platform for high-sensitivity magnetic field sensing.
• The sensor demonstrates excellent performance metrics, suitable for practical applications.
• The developed theoretical model aids in the design and optimization of future magnetic fluid-based fiber optic sensors.