Optical Hydrogen Gas Sensor Based on Palladium Coated Microring Resonator

Hydrogen (H-2) is being considered as a next generation energy and it shows major applications in chemical industries, aerospace and in agricultural sectors also. Hydrogen leakage monitoring has become very important because the presence of H-2 (>4%) in the surroundings can occur an explosion. So sensing of H-2 is very essential for environmental safety. In this paper, we have introduced a novel micro scale hydrogen gas sensor which is highly sensitive towards H-2. This proposed design is based on micro ring resonator. The hydrogen sensitive material Palladium (Pd) is deployed in the inner section of the micro-ring as a micro-disk. By reacting with H-2, this Palladium micro-disk has created a volumetric expansion. The resulting effect for the volumetric expansion caused a significant resonant wavelength shift. The resultant wavelength shift per percent of H-2 is 1132 pico-meter (pm), with an accuracy of +/- 10 pm. This sensitivity value is far better than some other existing hydrogen gas sensors. By using appropriate sensing layer, this gas sensor can also be used to detect different gases.