Feb 3 2011
Scientists at Princeton University have developed a new technology to produce a beam of laser light using air. The new air laser will assist scientists to measure airborne contaminants and enable soldiers to remotely detect concealed explosives.
In earlier remote laser-sensing techniques, the recurring light beam is a merely a reflection of the exiting beam. In the air laser, a new laser beam is produced by oxygen atoms and their electrons are agitated to high energy levels.
According to the scientists, an ultraviolet laser pulse is directed on to a small patch of air to agitate the electrons of the oxygen atoms to high energy levels that in turn produce a coherent laser beam that is targeted at the original laser.
Professor of Aerospace and Mechanical Engineering at Princeton University, Richard Miles said that the returning laser beam intermingles with air molecules and takes their fingerprints. Miles further said that to test the airborne pollutants, an air sample of that air needs to be collected. However, the remote sensing capability of the air laser eliminates this procedure. By testing the sample of the surrounding air, one can detect a bomb hidden on the road from a distance, he added.