Wavelength response of a surface plasmon resonance palladium-coated optical fiber sensor for hydrogen detection

An optical fiber using palladium as sensitive layer is characterized in the range of 450 to 900 nm. The sensitive layer is deposited on the outside of a multimode fiber, after removing the optical cladding. The sensor is based on a measurement technique that uses the surface plasmon resonance effect. A continuous change in output intensity is observed as a function of the hydrogen concentration between 0.5% and 4% H(2) by volume in Argon. The response shows that the transmitted intensity can either decrease or increase, depending on the selected wavelength. This behavior is directly related to the change in reflectance upon hydrogenation between the polarization s and p. The loading time is 30 s and the unloading time is 90 s in a mix of argon and 10% of oxygen. The detectors show a good reproducibility. (C) 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.3529432]