Characterization of an On-chip Photonic Waveguide gas Sensor

Abstract: Gas sensing in medical applications requiresmall, precise and sensitive sensors. This projecthas developed a laboratory setup for characterisationof a waveguide-based gas sensor for carbon dioxide andmethane working in the mid-IR range of 2 - 10 μm. Thissetup utilizes an IR-camera to image the waveguideswhen a mid-IR laser is coupled into them. Along thelaboratory work, a program for optimisation of waveguidelength has been made and a study of on-marketmedical carbon dioxide sensors has been done. Thelaboratory setup shows potential for good measurementof waveguide losses, but several problems was identifiedwith the measurement methods currently used. Fromthe sensor study, the standard performance for currentsensors is presented as well as areas where gas sensorscould be improved. Size, speed and accuracy were someof the characteristics a waveguide-based sensor couldimprove on and open up for new sensor application in,for example, hand-held medical devices.