The research on hydrogen sensor based on nanofiber

Abstract

Hydrogen is an important source used as an energy carrier and a chemical reactant or industrial material. However, if not handled properly, hydrogen content as low as 4% can lead to a life-threatening catastrophe. Hydrogen sensors with higher sensitivity, better selectivity, faster response, and wider dynamic range are of increasing importance in connection with the development. In this paper, a scheme of hydrogen sensor that satisfies these requirements with a single sensing element is proposed which is centered on a nanofiber. The sensor is based on stimulated Raman scattering spectroscopy but the tightly confined evanescent field associated with the nanofiber enhances the Raman gain per unitlength by a factor of more than 10⁴ over free-space beams. In addition, the homemade signal processing circuit plays an important role in the whole sensing system instead of the commercial instruments, which makes it possible to develop a principle prototype. The circuit intergrates tne DFB laser driver circuit, the photoelectric detection circuit and the main control circuit which outputs modulation signal and acts as a digital lock-in amplifier. Several silica nanofibers operating in the telecom wavelength band has been manufactured and measured in an experiment that demonstrates hydrogen detection from hundreds parts per million to 100%. The reported sensor could be used in the field of new energy, electric power and aerospace for detection of hydrogen leakage or monitoring of transformer health conditions with advantages of low cost, small size and outstanding performance.