Article Posted on : - Sep 18, 2011

WASHINGTON (PTI): Scientists have developed a new laser which they say can accurately detect roadside bombs and help identify improvised explosive devices (IEDs), often used by terrorists in countries like Afghanistan.

Researchers at Michigan State University who devised the laser said it has the sensitivity and selectivity to scan large areas and detect improvised explosive devices that account for around 60 per cent of coalition soldiers' deaths in Afghanistan.

Detection of IEDs is extremely challenging because the environment injects a large number of chemical compounds that mask the select few molecules that one is trying to detect.

But the new laser can make these distinctions even for quantities as small as a fraction of a billionth of a gram, said Professor Marcos Dantus, who led the research.

According to the researchers, the laser combines short pulses that cause molecules in the explosives to vibrate, as well as long pulses that are used to "listen" and identify the different vibrations.

Every kind of molecule has different vibrational frequencies that uniquely identify the substance, much like a fingerprint, the researchers said.

"The laser and the method we've developed were originally intended for microscopes, but we were able to adapt and broaden its use to demonstrate its effectiveness for standoff detection of explosives," Professor Dantus said in a statement.

The research, partly funded by the US Department of Homeland Security, was published in the journal Applied Physics Letters.