Chemical Sensor on a Chip

Using miniaturized laser technology, a tiny sensor has been built at the Vienna University of Technology which can test the chemical composition of liquids. They are invisible, but perfectly suited for analysing liquids and gases; infrared laser beams are absorbed differently by different molecules. This effect can for instance be used to measure the oxygen concentration in blood. At the Vienna University of Technology, this technique has now been miniaturized and implemented in the prototype for a new kind of sensor. Specially designed quantum cascade lasers and light detectors are created by the same production process. The gap between laser and detector is only 50 micrometres. It is bridged by a plasmonic waveguide made of gold and silicon nitride.