Self-compensated high-pressure sensor with a high-birefringence fiber Bragg grating and a bulk modulus

Abstract

High-pressure measurement is made by demodulating Bragg grating peak splitting caused by transverse stress differences in the core of a high-birefringence (HB) single-mode fiber, which is bonded on the exterior surface of a free active element bulk modulus. The two orthogonally polarized signals reflected from the HB fiber Bragg grating (FBG) can be independently detected with a simple FBG interrogation system, which is based on the light intensity measurement method. In addition, the cross-sensitivity of the FBG sensor can be self-compensated by this method. The measurement principle is introduced, and preliminary experimental results indicate that the measurement sensitivity is estimated to be ~12 pm/N in a linear measurement range from 0 to 120 N.