Researchers have developed and tested an infrared spectroscopy system that can rapidly detect chemical aerosols from a distance by using light reflected from common surfaces such as traffic signs, tree trunks or painted surfaces. The new method could make it possible to detect hazards without complicated instruments, helping improve safety and ease operations at industrial sites, public venues and other high-risk locations.

“Previously, many remote chemical detection systems have relied on placing a mirror or other highly reflective target in the field to bounce the laser signal back to the detector, which isn’t practical in many real-world situations,” said research team leader Tim Johnson from Pacific Northwest National Laboratory. “Our approach eliminates that requirement by using reflections from ordinary surfaces, allowing us to detect aerosolized chemicals from a distance without installing specialized equipment at the target location.”

In the journal Applied Optics, the researchers report results from laboratory tests using reflected infrared laser light from different surfaces. They showed that many nonmetallic surfaces could be used for aerosol and vapor detection at standoff distances of up to 11 meters (36 feet).