Abstract

A novel method was proposed to improve hydrogen sensitive performance of fiber Bragg grating (FBG) hydrogen sensor. The hydrogen performance of the sensor can be greatly improved by using WO₃-Pd₂Pt-Pt composite films as sensing element. The high reflective Bragg gratings was written in single mode fiber. The end-face of single mode fiber was deposited with WO₃-Pd₂Pt-Pt composite films as sensing element. The peak intensity of high reflective FBG is employed for reference, while that of baseline intensity of reflected light source is used as hydrogen characterization. The experimental results prove the resolution of the hydrogen sensing system can reach to 5 ppm, and the proposed sensor displays good repeatability during the hydrogen response.

© 2017 Optical Society of America