Research on demodulation of FBGs sensor network based on PSO-SA algorithm

In this paper, we report a novel demodulation algorithm of particle swarm optimization based simulated annealing (PSO-SA) for multiplexing fiber Bragg grating (FBG) sensor networks. We theoretically prove that multiple FBGs can be demodulated in a 2, 3 and 4-grating-network respectively even though the grating spectra are fully or partially overlapped and the demodulation resolution can reach 10 pm. Wavelength demodulation of a 4-grating-network with grating spectra overlapped is realized experimentally. To the best of our knowledge, this is the first time that four fully overlapped gratings are recognized. This method may find implications in massive multiplexing FBG sensor network.