Optimization of high-accuracy FBG wavelength demodulation based on spectral correction and algorithm compensation

Despite the widespread use of array waveguide gratings in fiber Bragg grating demodulation systems, its practical implementations are limited by nanoscale size control and processing accuracy, leading to spectral inconsistencies that affect wavelength demodulation. We propose a spectral correction and compensation algorithm combining bandwidth matching and Gaussian fitting to improve demodulation accuracy. Simulation results show a 74.5% relative improvement in demodulation accuracy under 0-4 dB insertion loss uniformity, with effective suppression of degradation. Experimental results further validate the algorithm, improving accuracy from 25.58 pm to 8.82 pm (65% relative improvement) under 3.88 dB spectral insertion loss uniformity.