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

Unlike usual spectral analysis of the fiber Bragg grating (FBG) 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 s1 with respect to pressure is studied theoretically and experimentally. A theoretical model for pressure sensing by use of s1 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.

► We review a new weak pressure sensor based on the Stokes parameter of FBG. ► Simulation results proved the theoretical feasibility of the proposed method. ► The dual-wavelength method can avoid the measurement error caused by the wavelength drift. ► The experimental results confirm the method can be used to measure weak pressure.