Highly Sensitive and Rapid FBG Hydrogen Sensor Using Pt-WO3 With Different Morphologies

The performance of spiral micro-structured fiber Bragg grating (FBG) and standard FBG hydrogen sensor with different morphologies of Pt-WO ₃ has been presented. Femtosecond laser was employed to fabricate spiral micro-sturctured on fiber cladding of FBG. WO ₃ nanorods, nanowires, and nanolamellae were synthesized by hydrothermal process and decorated with Pt nanoparticles by decomposing Pt(acca)2 precursor (molar ratio of Pt:W = 1:5). FBG hydrogen sensors with Pt-WO ₃ nanolamellae have the highest sensitivity (spiral microstructured FBG sensor ~208 pm/%H, standard FBG sensor ~110 pm/%H), followed by nanorod and nanowire sensors. Moreover, the sensitivity of the spiral micro-structured FBG sensors are about 1.8 ~ 2.5 times than that of standard FBG sensors. The results show that the sensors with WO ₃ nanowires have the fastest response time.