A squad of fully armed soldiers closely follows an armored Humvee, advancing cautiously through the ruins of an urban battlefield. About a kilometer ahead of them in the sky, a small drone hovers on the spot. Suddenly, a soldier screams, clutching his eyes with both hands as smoke curls between his fingers.

They were struck by laser beams emitted by the drone. A near-infrared laser with a wavelength of 1,080 nanometers can cause blindness at a power of just five microwatts. The intensity of the beam entering the eyes of these soldiers is 200 million times higher, reaching one kilowatt per square centimeter. If exposed skin were touched, the subcutaneous fat would be instantly vaporized.

A laser of such intensity is “enough to cut metal,” wrote a research team led by Li Xiao, a research associate at the school of optoelectronics. science and engineering from the National University of Defense Technology of the People’s Liberation Army of China, in a peer-reviewed article published in the Chinese journal Acta Armamentarii in October.

Li’s email prefix – “mad.li» – alludes to his unconventional thinking. The scenario he envisioned in his paper was once thought impossible: Generating a laser beam with a long kill distance typically requires bulky equipment the size of a truck. A small platform, similar to a consumer drone, could never carry such a powerful laser weapon and its accompanying power supply equipment.

Li and his colleagues invented a small and lightweight redirection device that allows drones equipped to receive powerful beams from the ground and reflect them onto enemy targets.