Surely you have seen more than once a smoker (although, fortunately, there are fewer and fewer), create, with the smoke of a cigarette or a pipe, a circle or rounded shape with the smoke that comes out of inhaling the cigarette or pipe . Dolphins can also get it in the form of rings made with water bubbles.
And indeed, donut-shaped structures called vortex rings are sometimes seen spinning through fluids. A standard vortex is an eddy in a liquid or gas, such as an eddy.
Now let’s imagine taking that spinning swirl, stretching it and folding it into a circle and joining it end to end. Well, this is precisely the definition of a vortex ring. These rings travel through the liquid or gas as they spin, and in the new vortex rings, described in new research published in the journal Nature Photonics, scientists explain how light behaves in a similar way: the flow of energy it swirls as the ring moves.
The researchers behind the study started with a vortex tube, a hurricane-like structure that they already knew how to create using laser light. The team used optical techniques to bend the tube into a circular shape, creating a vortex ring, so it seems that they are not as different as those that can be created with tobacco smoke or those created by dolphins with bubbles.
“That’s great,” says optics researcher Qiwen Zhan. This scientist is interested in seeing if they could create vortex rings from electric current or a magnetic field or even help scientists better understand how topology (the geometry of donuts, knots, and similar shapes) affects light . and how it interacts with matter.
Referencia: C. Wan et al. Toroidal vortices of light. Chenhao Wan and Qiwen Zhan/University of Shanghai for Science and Technology Nature Photonics. Published online June 2, 2022. doi: 10.1038/s41566-022-01013-y.
