Laser Technology Developed to Detect Improvised Explosives

Marcos Dantus (Michigan State Univ.)

Scientists at Michigan State University in East Lansing have developed a laser that in lab tests has shown the potential to detect roadside bombs, a destructive weapon encountered by American and allied forces in Iraq and Afghanistan. The team led by MSU chemistry professor Marcos Dantus published its findings in the current issue of the journal Applied Physics Letters (paid subscription required).

Finding improvised explosive devices before they are detonated is a difficult task, says Dantus (pictured left), because the environment introduces a large number of chemical compounds that mask the select few molecules being sought out. At the same time, you need to balance the need for greater sensitivity against the generation of false positive alerts, which can paralyze urban areas with closed roads and evacuations.

Dantus and colleagues have developed a laser that they say can distinguish explosives from arrays of similar compounds often found in urban environments, even for quantities as small as a fraction of a billionth of a gram. The laser methods they developed are also non-destructive, another requirement for use in populated areas.

The laser beam combines two types of complementary optical pulses: short pulses that stimulate the molecules and make them vibrate, and long pulses that are used to detect and identify the different “chords” generated by the combination of vibrations. The different vibrational frequencies of the chords uniquely identify every molecule, much like a fingerprint. The high-sensitivity laser can work with other surveillance and detection technology, such as cameras, and allows users to scan questionable areas from a safe distance.

This research is funded in part by the Department of Homeland Security, and has resulted in a lab-based model. Dantus hopes to find additional funding to take this laser from the lab to the field. Dantus is also the founder of BioPhotonic Solutions, a company started in 2003 to commercialize technology developed by his research group.

Read more: Students Develop Remote IED Detonation Technology

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