In today's world, we simply cannot do without lasers. We use them to print out documents, play CDs or DVDs, weld, cut, or bend car components, survey roads, monitor our bloodstream, and even remove tumors from our bodies. Now researchers from the Fraunhofer Institute for Applied Solid State Physics IAF in Freiburg have developed the technology for a further application. Their quantum cascade laser a particular type of infrared laser forms the core of an analysis apparatus that allows drinking water to be sampled automatically at the waterworks itself. As a result, water companies can determine within a few minutes whether their water contains any impurities and what those impurities are. The system has been designed in order to enable immediate identification of dangerous substances. "The equipment samples the water for dangerous substances at the waterworks itself in the course of routine operations, and allows for a rapid response," says Dr. Frank Fuchs, summarizing the advantages of the system. Dr. Fuchs is Fraunhofer IAF coordinator for the IRLSENS project, which is funded by Germany's Federal Ministry of Education and Research (BMBF).
To examine the components of water, experts use molecular spectroscopy: that is to say, they examine the optical spectra of the molecules in the water. Each chemical com-pound has a unique spectrum, since individual molecules vibrate and absorb light at characteristic frequencies. Water itself is a very strong absorber of infrared light; since the light sources employed to date have delivered little power, until now examinations of this sort have been possible only in a laboratory setting. "The main sticking point is the intensity of the light. In order to be in a position to employ molecular spectroscopy at the waterworks itself, we needed to find a more powerful light source," explains Fuchs.
Taking water samples in the course of routine operations
Fraunhofer IAF's quantum cascade laser
|Contact: Dr. Frank Fuchs|