Integrated optics ring-resonator chemical sensor with polymer transduction layer

An integrated optics chemical sensor based on a ring resonator with an ethyl cellulose polymer coating has been demonstrated. The measured sensitivity to isopropanol in air is 50 ppm-the level immediately useful for health-related air quality monitoring. The resonator was fabricated using SiO/sub 2/ and Si/sub x/N/sub y/ materials. The signal readout is based on tracking the wavelength of a resonance peak. The resonator layout optimisation for sensing applications is discussed.