A novel fiber Bragg grating sensor for weak pressure measurement based on the Stokes parameter

摘要

Unlike usual spectral analysis of the fiber Bragg grating (FBC) sensors, a novel weak pressure sensor based on the Stokes parameter of FBG is proposed in this paper. The evolution of the first normalized Stokes parameter s_1 with respect to pressure is studied theoretically and experimentally. A theoretical model for pressure sensing by use of s_1 is built and numerically simulation is also carried out. The dual-wavelength analytical method is proposed to reduce the influence of Bragg wavelength drift and improve the measurement accuracy. Under the pressure conditions of 0-5 N, the experimental pressure sensitivity is 0.0754/N. Good agreements between experiment results and numerical simulations verify the feasibility of the method.