Ethanol Sensor Based on Microring Resonator

Chemical sensors is gaining long-standing interests due to their applications in many areas such as bacterial and virus detection, medical diagnostics, drug development, food safety and environmental control. Among the existing chemical sensors, optical planar sensors show promising and attempt to beat their commercialized competitors because of their robustness, lable-free detection mechanism, mature complementary metal oxide semiconductor (coms) fabrication technology and naturally low cost. Silicon nitride microring resonators were demonstrated as chemical sensors. Using the technique of coms technology, the microring devices were fabricated with 200 µm in radius. Performance of the devices was measured, which showed the quality factor (q) was up to 25,000. Sensitivity of 108.9336 nm per reflective index unit (nm/riu) and detection limit of 1.836×10-4 riu were demonstrated by using various concentrations of ethanol solution as analytes.