A group of researchers from Shanghai University of Science and Technology in China and the University of Dayton in the United States have managed to develop a way to spin light into a swirl ring using mirrors, lasers and lenses. Based on previous work, in which it was sometimes possible to accidentally get vortex rings, scientists developed a special mathematical device and a system that can create such formations on demand. An article about this was published in the journal. Nature Photonics.
By examining the conditions that led to similar formations observed by another group of researchers in 2016, the scientists found a mathematical solution that shows how such rings can be formed – specifically, they found that solutions to Maxwell’s equations can be used to create the desired result. conformal mapping. Then a combination of materials was chosen, which led to the application of the specified mathematical solutions. To do this, we had to start by modifying a standard laser to produce a certain type of pulse. Later, mirrors, lenses, gratings and special types of liquid crystal screens were added for the passage of light pulses – each of these parts affected light in its own way.
The researchers note that the system initially learned to transform the light pulses into long narrow beams, and then, after passing through the system, they connected, twisted like the wind and turned into tornadoes, forming rings. In the future, it is planned to find out whether it is possible to obtain similar eddies in other ways.