2018 Volume 46 Issue 9 Pages 512-
We developed a novel fiber optic Surface Plasmon Resonance (SPR) hydrogen sensor based on heterocore structured fiber optics with multi-layer films of gold (Au), tantalum pentaoxide (Ta2O5), and palladium (Pd) that are uniformly coated on a cladding surface. In a light intensity-based experiment with Light Emitting Diode (LED) operation at 850 nm, we induced a transmitted loss change of approximately 0.23 dB with a response time of 15 s for 4% hydrogen in 25-nm Au, 60-nm Ta2O5, and 3-nm Pd multi-layer films. In addition, multi-point detection for hydrogen was successfully achieved using a combination of an SPR hydrogen tip sensor and an interrogating system based on Pseudorandom Noise-code Correlation Reflectometry (PNCR). The sensor gives optical loss changes with and without hydrogen absorption and shows Pd hydrogenation process in real time with high sensitivity, such as more than 0.4 dB.
