Spectral characterization of polarization dependent loss in fiber Bragg grating under local pressure and the analysis of secondary peak

In this paper, a study of the spectral characterization of polarization dependent loss (PDL) in fiber Bragg grating (FBG) under local pressure is presented and the evolution of the secondary peak is analyzed. The effects of the load magnitude, loaded length and loaded position on the amplitude and wavelength of the created secondary peak are investigated in detail. The numerical simulation based on the modified transfer matrix method is used to calculate the transmission and PDL response of the FBG. The theoretical analysis and numerical simulation demonstrate that the loaded length and load amplitude have significant effect on the characterization of the secondary peak. The results show that there is the potential in distributed FBG transverse load sensing by tracking the secondary peak of PDL variation.