A new infrared laser defense system for aircraft won't blow up incoming fire in mid-air, but it will protect them by blinding heat-sensitive missiles.
Roughly the size of a DVD player, the new system will likely be used in combat operations initially, but could eventually help local law enforcement uncover concealed drugs and explosives.
"We've used good, old-fashioned stuff from your telephone network to build a laser that has no moving parts," said Mohammed Islam, a scientist at the University of Michigan who developed this new laser-based missile defense system.
Unlike most lasers, which emit only a single wavelength of light, the new infrared laser emits a multitude of wavelengths -- all in the infrared range. Just as infrared light from the summer sun warms up the Earth, the infrared light from the lasers warms an incoming missile -- or more precisely, it warms the heat-sensor the missile uses to track aircraft.
Those sensors hone in on two heat sources: the aircraft's engine and the exhaust.
The infrared lasers mask the signature of those heat sources by making everything look like a heat source. "It's like throwing sand into the eyes of the missile," said Islam.
If the pilot turns sharply while the missile is blinded, he or she should should be able to evade the projectile and escape.
"It's an interesting approach to blind an incoming missile," said Anthony Johnson, a laser scientist at the University of Maryland, Baltimore County, who knows about the research but is not involved with it.
Other groups, notably Boeing, are developing airborne laser systems powerful enough to destroy -- not distract -- incoming missiles.
The Boeing laser, however, is quite large, uses a lot of electricity and is complex. Particularly appealing to Johnson is how Islam's system, which is being developed by a University of Michigan spin-off named Omni Sciences, uses existing and relatively inexpensive off-the-shelf equipment with no moving parts.
"Since it's fiber-based and uses telecommunications lasers, it should be quite compact," said Johnson.
The first prototype, developed in 2008, was about the size of a DVD player. By 2011 the Michigan scientists expect their device will be the size of a laptop computer while emitting infrared laser beams four times more powerful.
The device is small enough and durable enough to be mounted on aircraft. Helicopters will likely be the first aircraft equipped with this laser-defense system, Islam said. Airplanes will come later.
The military might not be the only beneficiary of this technology. Law enforcement agencies could equip their aircraft with infrared lasers to scan huge expanses of land to find drugs or explosives.
Each chemical has what's called a spectral fingerprint, a particular set of wavelengths that set them vibrating "like a tuning fork," said Islam.
It just so happens that the spectral fingerprint of explosives and illegal drugs lies within the infrared range.