Spectral response of polarization properties of fiber Bragg grating under local pressure

•It is shown that the s1 curves can be strongly affected by incident angle, load magnitude, loaded position and loaded length of the grating.•Establishing the polarization response of the FBG under local pressure could be used for recovering the load information for spatial measurement.•It will helpful in getting accurate information about the transverse stress in multi-dimensional sensor application.

A study of the spectral characterization of polarization properties of locally pressed fiber Bragg grating (FBG) is presented. The evolutions of the first Stokes (s1) parameter of a FBG as function of the incident angle, the load magnitude, the loaded position and the loaded length of the grating are investigated. The numerical simulation based on the modified transfer matrix method is used to calculate the s1 response and the state of polarization (SOP) of the FBG. The theoretical analysis and numerical simulation demonstrate that the evolutions of polarization dependent parameters contain the information about the transverse load and have potential applications for distributed diametric load sensor.