A two-laser system to identify chemicals from a distance is being developed at the Department of Energy's Oak Ridge National Laboratory

A two-laser system to identify chemicals from a distance is being developed at the Department of Energy's Oak Ridge National Laboratory. Ali Passian and colleagues present a technique that uses a quantum cascade laser to strike a target and another laser to monitor the material's response as a result of temperature-induced changes. That information, which is published in the Journal of Physics D: Applied Physics, allows for the rapid identification of chemicals and biological agents. This approach is similar to radar and lidar sensing techniques in that it uses a return signal to carry information of the molecules to be detected, but it also differs in a number of ways: it uses photothermal spectroscopy configuration and probe beam reflectometry in differing ways. All in all, this work represents a proof of principle success that could lead to advances in standoff detectors with potential applications in quality control, forensics, airport security, medicine and the military.