A novel metallized fiber Bragg grating sensor with a lower temperature sensitivity

When fiber Bragg grating (FBG) sensors are used to measure stresses and strains, the influence of the ambient temperature on the FBG should be avoided or compensated. The temperature sensitivity of a FBG can be decreased by using an appropriate coating on the FBG. A novel Ni-ZrO2 composite coated FBG sensor with a lower temperature sensitivity is developed in this study. Elemental distribution scan (EDS) tests show that the contents of Zr and Ni are 30.12 wt.% and 67.87 wt.%, respectively. Scanning electron microscope (SEM) tests show that the Ni-ZrO2 composite coating covers the fiber well. Temperature sensing experiments were conducted by using two Ni-ZrO2 coated FBGs in the temperature range of 30~90°C. The results show that the average temperature sensitivity coefficient decreases by 34.59% compared with the Ni-coated FBG, which indicates that the FBG with Ni-ZrO2 composite coating has a lower temperature sensitivity.