All-fiber magnetic field sensor based on narrow-bandwidth laser internal cavity modulation with coated magnetic fluid

Area of Science:

• Optoelectronics
• Magnetics
• Fiber Optics

Background:

• Traditional magnetic field sensors often face limitations in sensitivity and signal quality.
• Integrating magneto-fluidic materials with laser cavities offers a promising avenue for advanced sensing.

Purpose of the Study:

• To develop and characterize a novel magnetic probe structure utilizing magneto-fluidic and intra-laser cavity modulation.
• To enhance magnetic detection sensitivity and signal-to-noise ratio (SNR) for improved magnetic field sensing.

Main Methods:

• A single-mode-no-core-single-mode fiber structure coated with magnetic fluid was employed as the sensing element.
• The fiber sensing element was integrated within the internal cavity of a laser for intra-cavity modulation.
• The system utilized laser internal cavity modulation to interrogate the magnetic fluid's response.

Main Results:

• The developed magnetic probe achieved a high magnetic detection sensitivity of 1.76 × 10^-3 mW/Oe with excellent linearity (99.709%).
• The sensor demonstrated a narrow half-height width (FWHM) of less than 40 pm, indicating high spectral resolution.
• Low temperature sensitivity (0.035 μW/°C) and a limit error of ±0.006035% were recorded.

Conclusions:

• The magneto-fluidic and intra-laser cavity modulation approach significantly enhances magnetic field sensing performance.
• This novel sensor structure offers a promising solution for high-sensitivity, high-SNR magnetic detection applications.
• The achieved performance metrics suggest potential for advanced applications in magnetic field monitoring and measurement.