High-powered infrared laser weapons could be on the horizon after scientists figured out how to make lasers nine times more powerful.
Militaries have already deployed laser-powered weapons, as popularized by films like "Star Wars,", but they're much weaker than those seen on screen and can only disable small airborne targets.
The light In these current weapons, which is invisible to the naked eye, comes from single-mode optical fiber — which transmits a single wavelength of light, or mode, through the fiber core — and generates a focused beam. But it's difficult to increase the power because the light is confined to a tiny area.
Multimode optical fiber — which transmits multiple light modes — is much wider and can boost the power of infrared light emitted between three to nine times — but this technology generates beams that are messy and unfocused, due to scattering. That means their power dissipates rapidly over long distances.
In a new paper published Nov. 19 in the journal Nature Communications, scientists found a solution that limits how much light scatters from multimode fibers. In theory, it means militaries could design lasers that are both high-powered enough to cause significant damage and focused enough to form a smooth, narrow beam. The new research was funded by the U.S. Air Force.
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"A bad quality laser beam will diverge very rapidly as it propagates and therefore cannot deliver a concentrated amount of energy to the target. We have a way to control the property of light in such fibre so that it emerges as a focused point that can be turned into a narrow high-quality beam,", lead authors Stephen Warren-Smith and Linh Nguyen, researchers at the University of South Australia's Future Industries Institute, told Live Science in a jointly written email.
The defense sector has been developing military-grade lasers for years and is vying to deploy them in the real world. Lockheed Martin, for instance, announced plans this year for a 500 kilowatt-class laser for use in directed-energy weapons systems to defend against threats.
The team behind the new study hasn't developed a prototype for such a weapon. But any lasers created using their blueprints may be powerful enough to confuse enemy navigation systems or deal significant thermal damage to vehicles or machines.
Current technology can zap small targets in the air at close range. But the new technology could be used on a much broader range of targets.
"The laser beam is focused on a distant target for perhaps a few seconds, which causes the target to melt or burn. This is most effective for small targets such as drones and mortars, but potentially larger targets if specific critical systems are damaged, such as onboard sensors or electronics," the researchers wrote in their email.
This doesn't mean the technology could be used to produce a Death Star any time soon, however. Rather, it's more likely the technology would be used to disable autonomous drones. It's very costly to expend ammunition to take drones down, but laser weapons offer an almost unlimited "magazine," with electricity as the only input energy source, the researchers said.
Beyond use in weaponry, the researchers think such powerful lasers could be used in remote sensing. High-powered lasers could, for example, determine wind speeds at a much further distance than conventional methods. High-powered lasers are also pivotal to research into gravitational wave detection, the researchers said, and they hope their discovery plays a role in future research endeavors.