The detection of gases such as methane (for fuels) and ethylene (for fruit ripening) is important in many industrial and commercial contexts. Existing sensors exhibit many problems in practice. This research program is currently developing new sensors based on semiconductor infrared sources including LEDs and lasers. A particular focus is on the signal processing aspects of the sensors, so as to provide useful gas concentration measurements in the presence of background noise, utilizing with low-cost sensors. The group has published internationally in prestigious journals and is seeking high-calibre students with a background in digital signal processing, electronics, fibre optics, lasers, and acoustics.