Nano-structured Pd-long Period Fiber Gratings Integrated Optical Sensor for Hydrogen Detection
A fiber-optic sensor for detecting hydrogen at various temperatures (30-200 °C) is reported in this paper. The sensor is composed of a long period fiber gratings coated with a nano-structured Pd thin layer as the sensing material. The sensing principle of the designed sensor is based on the change of the refractive index of the Pd thin layer upon exposure to hydrogen, which causes the resonance wavelength shift of the long period fiber gratings. The Pd layer prepared by sputter deposition has nanograins of 30-40 nm in size. The resonance wavelength of the long period fiber gratings coated with Pd decreases as hydrogen concentration increases from 0% to 16% at all temperatures. There is a significant wavelength shift of the sensor when the Pd film goes through the phase transition between α and β phases. The sensor has a short response time with a relatively slower recovery rate. The sensor maintains its functionality after several cycles of hydrogen detection and recovery.
X. Wei et al., "Nano-structured Pd-long Period Fiber Gratings Integrated Optical Sensor for Hydrogen Detection," Sensors and Actuators B: Chemical, Elsevier, Sep 2008.
The definitive version is available at http://dx.doi.org/10.1016/j.snb.2008.06.018
Electrical and Computer Engineering
United States. Department of Energy
Keywords and Phrases
Pd; Hydrogen Sensor; Long Period Fiber Gratings; Response Time; Stability
Article - Journal
© 2008 Elsevier, All rights reserved.