Pressure sensor based on a free elastic cylinder and birefringence effect on an FBG with temperature-compensation

Based on a free active cylinder bulk-modulus and the birefringence effect on a fiber Bragg grating (FBG), pressure measurement is implemented by demodulating fiber Bragg grating peak splitting caused by transverse stress differences in the core of a single mode fiber, which is bonded on the exterior surface of the cylinder. The two orthogonally polarized signals reflected from the compressed 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 temperature and strain of FBG sensor can be self-compensated by this method. Measurement principle is introduced, preliminary experimental results indicate that the measurement sensitivity is estimated to be ∼27 pm/Mpa in a measurement range from standard atmosphere pressure to 100 MPa.