Response Characteristics of Silicon Microring Resonator Hydrogen Gas Sensor

抄録

A novel optic sensor using platinum-loaded tungsten oxide (Pt/WO₃) and a silicon microring resonator for detection of hydrogen gas at room temperature was developed and tested. The sensing principle is mainly based on the resonant wavelength shift caused by the catalytic combustion reaction of hydrogen. In a previous study, it was found that Pt/WO₃ film could not be deposited uniformly on the surface of the microring. To solve this problem, acetylene glycol surfactant was used and mixed with Pt/WO₃ precursor solution. Electron probe microanalyzer images of the device surface showed that the Pt/WO₃ layer successfully covered the target part of the microring. When this device was tested, a 580-pm resonant wavelength shift was observed after 20-min exposure to pure hydrogen gas at room temperature. When the previous device was tested under the same condition, a 160-pm resonant wavelength shift was observed, so the sensitivity (defined by the wavelength shift after 20-min exposure to sample gas) of the developed device was approximately four times larger than that of the previous one.