At Aalto University, researchers have developed a groundbreaking technique for creating tiny light vortices — swirling “hurricanes” of light capable of carrying information.
Tiny hurricanes of light could be used to transmit information. Image Credit: Aalto University
These light vortices, which could potentially revolutionize data transmission, are produced using metallic nanoparticles manipulated by an electric field, arranged in a unique quasicrystal geometry.
Half Order and Chaos
These light vortices resemble miniature hurricanes within a beam, with a calm, dark center surrounded by a ring of bright light, much like the calm "eye" of a hurricane created by opposing winds. Here, the dark center forms because the electric field surrounding it points in different directions across the beam.
Past physics research has shown that the kind of vortex formed depends on the symmetry of its structure. For example, arranging nanoscale particles in squares creates a single vortex, while hexagonal patterns produce a double vortex. More complex vortices need at least octagonal shapes.
Now, the Aalto team has unlocked a way to create geometric shapes capable of producing vortices of virtually any kind.
This research is on the relationship between the symmetry and the rotationality of the vortex, i.e. what kinds of vortices can we generate with what kinds of symmetries. Our quasicrystal design is halfway between order and chaos.
Päivi Törmä, Professor, Department of Applied Physics, Aalto University
Good Vibrations
The team’s design required arranging 100,000 metallic nanoparticles, each about one-hundredth the width of a human hair. The key breakthrough lay in identifying where these particles had minimal rather than maximal interaction with the electric field.
An electrical field has hotspots of high vibration and spots where it is essentially dead. We introduced particles into the dead spots, which shut down everything else and allowed us to select the field with the most interesting properties for applications.
Jani Taskinen, Doctoral Researcher, Department of Applied Physics, Aalto University
This discovery opens the door to further research in the vibrant field of light’s topological study. It also marks the initial steps toward a highly effective method for transmitting information in fields that rely on light for encoding data, such as telecommunications.
We could, for example, send these vortices down optic fiber cables and unpack them at the destination. This would allow us to store our information into a much smaller space and transmit much more information at once. An optimistic guess for how much would be 8 to 16 times the information we can now deliver over optic fiber.
Kristian Arjas, Doctoral Researcher, Department of Applied Physics, Aalto University
Scaling up and finding practical applications for the team’s design will likely require years of engineering advancements. Meanwhile, Aalto University’s Quantum Dynamics group remains deeply engaged in research on superconductivity and enhancing organic LEDs.
Their study was conducted using the OtaNano research infrastructure, which supports nano-, micro-, and quantum technologies.
Journal Reference:
Arjas, K., et al. (2024) High topological charge lasing in quasicrystals. Nature Communications. doi.org/10.1038/s41467-024-53952-5.