An EMD-based filtering algorithm for the long period fiber grating sensing

In this work, we employed the Empirical mode decomposition (EMD) algorithm into the demodulation spectrum of the long period fiber grating sensing experiment. After data processing by the EMD-based filtering algorithm, the disordered noise of the fiber Bragg fiber grating (LPFG)’s spectrum caused by the laser source and mode coupling can be effectively eliminated so that the single valley wavelength of LPG can be much more precisely located. As a consequence, based on the proposed algorithm, the related sensitivity of refractive index solution detection can be reached 11 nm/RIU, 18 nm/RIU, 61.3 nm/RIU and 241 nm/RIU in 1.33-1.36, 1.37-1.39, 1.40-1.43, and 1.43-1.45 refractive index region, respectively.