The rays generated during thunderstorms were converted for the first time in the world into a laser, which is located in a telecommunications tower on Mount Santis, at an altitude of 2,500 meters in northeastern Switzerland, which naturally receives about 100 lightning bolts a year.
The goal of this investigation, led by scientists from France and Switzerland, is to improve the protection of airports and space bases, among other infrastructures, using technology. Although traditional lightning rods that have been in use since the 18th century are very effective, “damage from lightning costs billions of dollars each year,” explain the authors of the research published in the journal. Nature Photonicsthis monday.
Unlike a traditional lightning rod, which simply directs the lightning current to the ground, a laser lightning rod allows for better control, according to the researchers who estimated that there are 40 to 120 rays per second, including those that occur in clouds and do not reach the ground.
It was “a bit of a crazy idea,” admitted the first author of the paper at the Ecole Polytechnique de Paris, Aurélien Houard when he explained that the purpose of this device was to allow the use of air filaments containing free electrons formed into high-energy laser beams. These electrons were separated from the atoms, forming ionized air, and this prompted the specialist when he explained that in this way, the threads act as good electrical conductors that provide a point of attraction for the electrical discharges generated by thunderstorms.
This concept was first proposed, albeit in theory only, in 1974 and has since been explored experimentally in laboratories. In the summer of 2021, the Mount Säntis Project in Switzerland applied it for ten weeks, during which 16 lightning strikes were recorded on the communications tower.
The laser light source, built on the base of the 124-meter-tall tower, enables laser beams to be directed in order to pass through the tip of the tower. The design of the installation makes it possible to control the production of electrically conductive filaments more than a kilometer high, and according to the results, the laser can direct a beam from storm clouds to a conventional lightning rod at the top of a communications tower.
“This application of laser filaments has been proposed for decades, but has never been demonstrated in a practical case as clear as this investigation,” confirmed Lluís Torner, director of the Institute of Photonic Sciences (ICFO) in Castelldefels, Spain.
At the moment, this technology is only a trial experiment and is not yet ready for large-scale implementation. “These preliminary results must be confirmed in additional campaigns,” warn the authors of the investigation, led by the Polytechnic Institute of Paris and the University of Geneva, and conclude that “this work represents an important step in the development of protection against laser radiation for airports, launch towers, or large infrastructure.”
