A laser beam that makes molecules vibrate could help detect improvised explosive devises, say scientists.

Every molecule vibrates with a unique frequency - so the laser could "sense" bombs while scanning the ground from a safe distance.

The Michigan State University team's work is another attempt to curb the number of deaths from roadside bombs in places such as Afghanistan.

The research appears in the journal Applied Physical Letters.

An improvised explosive device is a homemade bomb and more than half the deaths of coalition soldiers in Iraq and Afghanistan have been as a result of IEDs.

The lead developer of the laser sensor, Dr Marcos Dantus said detecting IEDs has always been a challenge because of the chemical compounds present in the environment that mask the bomb's molecules.

"Having molecular structure sensitivity is critical for identifying explosives and avoiding unnecessary evacuation of buildings and closing roads due to false alarms," he said. The invention uses a laser beam that combines short pulses that "kick" the molecules to make them vibrate with longer pulses.

"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," said Dr Dantus.

The researcher said he was not able to describe the technology behind the invention in great detail because of the project's sensitive nature.

Gene Roddenberry either was way ahead of his time... or knew some aliens!!