Temperature-compensated high pressure FBG sensor with a bulk-modulus and self-demodulation method

A free active element bulk-modulus based fiber Bragg grating (FBG) high pressure sensor and self-demodulation method for FBG wavelength shift signals are presented. With a simple isosceles triangle cantilever structure, problems of cross-sensitivity and chirped-signal in FBG sensor and are solved. In addition, unlike other FBG-based sensors which have separated sensing and demodulating element, this FBG-based high pressure sensor has only a single structure unit for both sensing and demodulating. Measurement principle and theoretical analysis are introduced. Simulation results and preliminary experimental results indicate that the measurement resolution of pressure can reach 0.1 MPa in a range from standard atmosphere pressure to 100 MPa.