Design of fiber grating sensor with polymer packaged for simultaneous measurements of pressure and temperature

A small volume fiber Bragg grating (FBG) sensor head is designed by using especial package technique with polymer material to measure the pressure and temperature simultaneously, which can solve the temperature cross-sensitivity of FBG effectively. We measure the pressure and temperature simultaneously using only one grating by measuring the wavelength of the two reflective peaks with different pressure and temperature sensitivity coefficients through the process of packaging FBG. Due to the wavelength resolution of 0.002nm, the resolution of the pressure and temperature measurements are 0.36 MPa and 0.30 degrees C for grating A, 0.14 MPa and 0.12 degrees C for grating B.