If a metal is hit suddenly and with force with light then as a result the electrons on the outer layer flow into waves which are named as plasmons. They give off light of their own body. The studies show that the frequency of that emitted radiation (light) is actually tells about the electronic characteristic nature of the surface of the metal. This light is likely to be readily affected by contaminations.Kevin Tetz has worked on this phenomenon in collaboration with his fellow scientists. They belong to the Ultrafast and Nanoscale Optics Group at the University of California, San Diego. They succeeded in designing a system to use them in trying for any surface contamination on the surface of any material.
They took a slim layer of metal and then drilled it with nanoscale holes by placing it onto the surface of the material being examined. They bombarded the perforated metal plate with laser light. In a result of that zapping, the surface plasmons gave off light; that emitted light’s frequency was the result of the particles hitting the plate. A sensitive light detector is required to get the measurements of the frequency of light being emitted.
The team working on this idea tells that by using this approach on latest devices will make them smaller in size and portable. The devices will function on low power. They would be able to determine the existence of anything from explosive substances to bacteria.
The only one thing which is required is to build a system having the capability to decode the light signatures.