Physicists create microhurricanes of light to transport large-scale data

Nov. 12 () –

Physicists at Aalto University have discovered a new way to create tiny hurricanes of light, known to scientists as vorticeswhich can carry information.

The method is based on the manipulation of metal nanoparticles that interact with an electric field. The design method, which belongs to a class of geometries known as quasicrystals, was devised by PhD researcher Kristian Arjas and carried out experimentally by PhD researcher Jani Taskinen, both from Professor Päivi Törmä’s Quantum Dynamics group.

The discovery represents a fundamental advance in physics and carries the potential of completely new ways of transmitting information.

In this case, a vortex is like a hurricane that forms in a beam of light, in which a quiet, dark center is surrounded by a ring of bright light. Just as the eye of a hurricane is calm because the winds around it blow in different directions, the eye of the vortex is dark because of the electric field of bright light pointing in different directions on different sides of the beam.

Previous physical research has related the type of vortices that can appear with the degree of symmetry that exists in the structure that produces them. For example, if nanoscale particles are arranged in squares, the light produced has a single vortex; the hexagons produce a double vortex, and so on. More complex vortices require at least octagonal shapes.

Now, Arjas, Taskinen and the team discovered a method for creating geometric shapes that, in theory, They admit any type of vortex.

“This research focuses on the relationship between vortex symmetry and rotationality, that is, what types of vortices we can generate with what types of symmetries. Our quasicrystal design is halfway between order and chaos,” says Törmä in a statement.

In their study, the group manipulated 100,000 metal nanoparticles, each about one-hundredth the size of a human hair, to create their unique design. The key was finding where the particles interacted less with the desired electric field rather than more.

“An electric field has high-vibration hot spots and points where it is essentially dead. We introduced particles into the dead spots, which turned off everything else and allowed us to select the field with the most interesting properties for the applications“says Taskinen.

The discovery opens up a wealth of future research in the very active field of the topological study of light. It also represents the first steps toward a powerful way to transmit information in domains where light is needed to send encoded information, including telecommunications.

“We could, for example, send these vortices through fiber optic cables and decompress them at the destination. This would allow us to store our information in a much smaller space and transmit much more information at once. An optimistic estimate of how much It would be 8 to 16 times the information that we can now send via fiber optics“says Arjas.