Researchers at the University of Michigan are developing laser systems for protecting military helicopters from heat-seeking missiles. The lasers wouldn’t shoot down the missiles, but would instead jam their sensors, essentially blinding them. This isn’t the first time that laser systems have been used for this purpose, but the creators of this system claim that it is better suited to helicopters than anything that has come before.
The UM system detects incoming missiles, then shoots at them with a mid-infrared supercontinuum laser. While most lasers emit light of just one wavelength, supercontinuums pack a broad range of wavelengths into their focused beam. Although such lasers typically emit a beam of visible light, due to the fact that this is a mid-infrared supercontinuum, its beam isn’t seen but is felt as heat. The resulting broad spectrum infrared beam mimics the electromagnetic signature of a helicopter engine, and causes the missile to lose track of where the actual helicopter is. It is said to be effective up to a distance of 2.9 km (1.8 miles).
One of the big strengths of this system, according to its makers, is its simple design and off-the-shelf fiber optic parts. “The laser-based infrared countermeasures in use now for some aircraft have 84 pieces of moving optics. They couldn't withstand the shake, rattle and roll of helicopters,” said Mohammed Islam, a professor in the Department of Electrical Engineering and Computer Science. “We've used good, old-fashioned stuff from your telephone network to build a laser that has no moving parts.”