High-precision and wide-wavelength range FBG demodulation method based on spectrum correction and data fusion

Area of Science:

• Optoelectronics
• Sensing Technology
• Internet of Things (IoT)

Background:

• Fiber Bragg Grating (FBG) sensors are crucial for IoT sensing layers.
• Accurate FBG wavelength demodulation is vital for reliable sensor data.
• Current demodulation methods lack sufficient accuracy and stability.

Purpose of the Study:

• To enhance the accuracy and stability of FBG wavelength demodulation.
• To address limitations of existing FBG demodulation techniques.
• To propose a novel composite gas cell demodulation scheme.

Main Methods:

• A composite gas cell demodulation scheme was developed.
• Techniques include spectrum correction and data fusion.
• Differential photodetectors and fitting extrapolation were employed.

Main Results:

• The new method significantly improved FBG demodulation performance.
• Maximum repeatability error was 2.51 pm; linearity reached 99.9%.
• Maximum full-scale error was ±1.71 pm across a wide temperature range, a 54.3% improvement.

Conclusions:

• The proposed composite gas cell demodulation scheme effectively enhances FBG sensing accuracy and stability.
• This advancement is critical for reliable IoT applications.
• The method overcomes noise, temperature drift, and spectral distortion issues.