Washington, July 8 : Researchers at Oak Ridge National Laboratory in Tennessee have developed a laser system that can safely tell if a suspicious package is an explosive, from up to 100 meters away.
"There are a number of ways to look for explosives. But its a lot nicer if you don't have to walk up to a bomb to find out what it is," Discovery News quoted Oak Ridge National Laboratory researcher Larry Senesac, as saying.
According to scientists, the same technology that can help save soldiers from roadside bombs can also eventually spare civilians from food poisoning.
The system is based on a series of quantum cascade, solid state lasers.
Each laser sends out a pulse of light in specific infrared frequencies.
When the lasers hit an object coated with residue from explosives, the light scatters. Some of it bounces back and is picked up by quartz crystals, which act like tuning forks, changing the electromagnetic waves into acoustic waves.
By determining which quartz crystals are activated, and running that specific activation signature through a computer with the chemical signatures of known explosive agents, the system can determine which type of explosive was used.
"This is the first device of its kind," said Charles Van Neste, also of Oak Ridge National Laboratory and the lead author on the paper, which appears in Applied Physics Letters 92.
The new system is so sensitive it can even pick up traces of TNT and other explosives floating in the air. In a different setting, the same system could be programmed pick up signatures associated with spoiled food.