It seems like any time I hear of laser pointers lately it's in the context of someone stupid doing something dangerous with them, like pointing them at aircraft. Stories like those are enough to make you want to keep them out of public hands entirely, but new research says that green laser pointers can actually be used for something good too. Researchers found that the hand-held lasers could be used to detect hazardous chemicals, even in very trace amounts.
The researchers at Ben-Gurion University of the Negev used an ordinary green laser pointer to create a Raman spectrometer. According to The Optical Society, "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."
The green laser pointer is especially well-suited in this set up because the short wavelength actually helped improve the detection of the spectrometer. Also, because the laser pointer allows the system to be small and easily manageable, the spectrometer can easily sweep across a sample to locate areas of greater interest and then examine those more closely.
The portability is key. Having a tool like this in a compact form means law enforcement or other officials in the field can easily use it to detect substances harmful to the environment or human health and safety, even in minute quantities.
“Since the overall system is modular, compact, and can be readily made portable, it can be easily applied to the detection of different compounds and for forensic examination of objects that are contaminated with drugs, explosives, and particularly explosive residues on latent fingerprints,” said Ilana Bar, a researcher with the Department of Physics at Ben-Gurion University of the Negev.