Novel technology for depositing a Pd-Ag alloy film on a tapered optical fibre for hydrogen sensing

摘要

Pd-Ag alloy thin films have attracted much attention in view of their potential applications in sensing hydrogen. In this paper we report on a new method of deposition of a high quality homogeneous Pd-Ag thin film on an optical fibre. The deposition method is used to fabricate sensors, which can detect hydrogen at very low concentrations (below 4%), by depositing a Pd-Ag thin film on tapered optical fibres. The deposition method and the complete method for fabrication of the tapered optical fibre sensors are presented in detail, as well as measurements of the hydrogen concentration in a nitrogen atmosphere made using the fabricated sensors. The sensors show good sensitivity and the optical responses of the sensors are in good agreement with theory.