抄録
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.
