Optical Fibre Hydrogen Sensors Based on Palladium Coatings

• Type: Article in International Conference Proceedings Book
• Date: 2011

Authors

Coelho, L (Author) Other; Silva, SFO (Author) FCUP; Paula A R Tafulo (Author) Other; Santos, JL (Author) FCUP; Frazao, O (Author) FCUP; Malcata, FX (Author) Other

Conference proceedings International

Title: International Conference on Applications of Optics and Photonics

International Conference on Applications of Optics and Photonics

Braga, Portugal, 3 a 7 de Maio de 2011

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 0 Citations

Scientific classification

FOS: Engineering and technology > Electrical engineering, Electronic engineering, Information engineering

Other information

Authenticus ID: P-002-X81

DOI: 10.1117/12.892014

Abstract (EN): Optical fibre sensors for Hydrogen detection at low concentrations has become a growing research area using Palladium as an active medium. Palladium is widely used in hydrogen sensing as it show a high and selective affinity for hydrogen. This metal is capable to absorb hydrogen up to 900 times its own volume which permits that during the expansion mechanical forces are applied in the fibre modifying the optical response. Several optical fibre hydrogen sensor heads coated with Palladium are presented and compared using different working principles: interferometric, intensity and fiber grating-based sensors. These principles were applied in Fabry-Perot cavities, fibre Bragg gratings written in fibre SMF28 with etching in the cladding, multimode interferometers and fibre end micro-mirrors. Palladium thin film coatings over the fibre surface and with thicknesses from 10nm to 350nm were produced by using the sputtering RF technique. These studies were performed in a Hydrogen/Nitrogen atmosphere with Hydrogen concentrations from 0% to 4% (lower limit explosion). The Bragg grating inscribed in a fibre with reduced cladding diameter appears to be one of the best approaches for a fibre optic sensing head for Hydrogen detection. Future work will continue the investigation of other fibre optic structures with Hydrogen sensing capabilities and their application in specific field situations will be assessed.

Language: English

Type (Professor's evaluation): Scientific