From Lectures to Explosives Detection: Green Laser Pointer Identifies Traces of Dangerous Chemicals in Real-Time

By using an ordinary green laser pointer, the kind commonly found in offices and college lecture halls, an Israeli research team has developed a new and highly portable Raman spectrometer that can detect extremely minute traces of hazardous chemicals in real time.

The new sensor’s compact design makes it an excellent candidate for rapid field deployment to disaster zones and areas with security concerns. The researchers will present their findings at Laser Science XXVIII—the American Physical Society Division of Laser Science’s Annual Meeting—collocated with the Optical Society’s (OSA) Annual Meeting, Frontier in Optics (FiO), taking place in Rochester, N.Y. next week.

Raman spectrometers rely on highly focused beams of light at precise wavelengths to illuminate small samples of materials. Very sensitive detectors then study the spectra of light that has been re-emitted, or scattered, by the sample. Most of this scattered light retains its original frequency or color, but a very small percentage of that light is shifted ever so slightly to higher or lower wavelengths, depending on the unique vibrational modes of the sample being studied. By comparing the shifted and the original wavelengths, it’s possible to determine the precise chemicals present in the sample.