Characteristics of highly sensitive hydrogen gas sensor based on Pt-SiO<sub>2</sub>/Si microring resonator
Junpei Igarashi, Shinji Okazaki, Yoshiaki Nishijima, Akio Higo, Taro Arakawa
Abstract
Abstract A hydrogen gas sensor based on a silicon microring resonator (MRR) with a Pt–SiO 2 thin film as a hydrogen-sensitive film is proposed and investigated to realize a high-sensitivity hydrogen sensor. The sensor detects hydrogen on the basis of the resonant wavelength shift caused by the reaction heat generated in the Pt–SiO 2 film. In the hydrogen exposure measurement, resonant wavelength shifts of approximately 5.0 and 2.4 nm were observed at hydrogen concentrations of 4.0 and 0.4 vol%, respectively, showing the high sensitivity of the proposed sensor. In addition, an MRR sensor with an upper Al 2 O 3 cladding layer is proposed and its higher sensitivity is theoretically demonstrated.