Title :
H2 Sensing Based on a Pd-Coated Tapered-FBG Fabricated by DUV Femtosecond Laser Technique
Author :
Silva, S. ; Coelho, Luis ; Almeida, Jussara M. ; Frazao, Orlando ; Santos, Jose Luis ; Malcata, F.X. ; Becker, Matthias ; Rothhardt, Manfred ; Bartelt, Hartmut
Author_Institution :
INESC Porto, Porto, Portugal
Abstract :
An optical fiber probe sensor based on a tapered-fiber Bragg grating (FBG) coated with 150-nm-thick Pd film is proposed for hydrogen detection. The FBG was written in a 50-μm-diameter tapered fiber by deep ultraviolet femtosecond laser technology. A second FBG was inscribed in the 125 μm-fiber section for temperature compensation. The sensing head was able to detect H2 concentration in the range 0%-1% (v/v) H2 at room temperature; a maximum sensitivity of 81.8 pm/% (v/v) H2 was attained with temperature compensation. The influence of the Pd coating over temperature sensitivity of standard and tapered-FBGs is also presented.
Keywords :
Bragg gratings; fibre optic sensors; gas sensors; hydrogen; laser materials processing; optical fibre fabrication; optical films; palladium; H2; Pd; deep ultraviolet femtosecond laser technique; gas sensing; optical fiber probe sensor; sensing head; size 125 mum; size 150 nm; size 50 mum; tapered fiber Bragg grating; temperature compensation; temperature sensitivity; Fiber gratings; Hydrogen; Optical sensors; Temperature sensors; Ultrafast optics; Femtosecond laser technique; fiber Bragg grating; hydrogen sensor; palladium; pressure;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2013.2239985
