Characteristics of Highly Sensitive Hydrogen Sensor Based on Pt-SiO2/Si Microring Resonator

We propose a compact and sensitive optical hydrogen gas sensor based on a Si microring resonator (MRR) with a Pt-SiO 2 thin film. The sensing characteristics of a fabricated Si MRR are experimentally investigated. The resonant wavelength shift of approximately 1.5 nm is measured for 4.0 vol.% hydrogen gas, showing a high sensitivity to hydrogen.