High-sensitivity fiber grating pressure sensor

A high-sensitivity fiber Bragg grating(FBG) pressure sensor was designed by encapsulating some gas with cylindrical vessel and its close plug which can move smoothly along the vessel, and sticking two ends of the FBG to the outer side of the vessel and plug. The variation of external pressure results in the change of tension in the FBG, then the pressure can be measured by testing the Bragg wavelength. The experimental results show that the pressure sensitivity coefficient is up to -0.696/MPa, which is about 3.515×10⁵ times of bare FBG, and the correlation coefficient is 0.9989. This sensor can be used to measure pneumatic, hydraulic and acoustic pressures as well as vibration.