According to a team of Harvard physicists, the structure of the optically rotating animal continues in a logarithmic spiral.
The evolution of light beams carrying the optical decy as a function of propagation distance. Image credits: Dorrah et al. , doi: 10.1126/sciadv.adr9092.
“This is a new behavior of light consisting of optical vortices that propagate space and change in an anomalous way,” says Professor Federico Capaso, a senior author of the study.
“It can potentially help you manipulate small substances.”
With a unique twist, the researchers have discovered that orbital angular momentum-mediated beams of light grow in mathematically recognizable patterns found throughout nature.
Reflecting the Fibonacci number sequence, their optical rotations propagate into logarithmic spirals found in Nautilus shells, sunflower seeds, and tree branches.
“It was one of the unexpected highlights of this study,” says Dr. Ahmed Dora, the first author of the study.
“Hopefully we can help others, who are experts in applied mathematics, to further study these light patterns and gain unique insight into their universal signature.”
This study is based on previous research by the team using thin lenses etched with thin nanostructures to create a light beam with controlled polarization and orbital angular momentum along its propagation path, converting the input of light into other structures that change when it moves.
Now they have introduced another degree of freedom in their light. There, spatial torque can be changed as it propagates.
“We show even more versatility in control and we can do it on a continuous basis,” said Alfonso Palmieri, co-author of the study.
Potential use cases for such exotic rays involve the control of very small particles, such as colloids, in suspension, by introducing new types of forces according to the unusual torque of light.
It also allows for precise optical tweezers for small operations.
Others have demonstrated light that changes torque using high-intensity lasers and bulky setups, but scientists have created theirs with a single liquid crystal display and a low-intensity beam.
By showing that they can create rotary rotary devices in industry-compatible, integrated devices, the barriers to entry for their technology to become a reality are much lower than in previous demos.
“Our research expands the previous literature on structured light, providing new modalities for light and physics, and sensing, suggesting similar effects of condensed material physics and Bose-Einstein condensates,” they concluded.
study Published in the journal Advances in science.
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Ahmed H. Dora et al. 2025. Rotation of light. Advances in science 11 (15); doi:10.1126/sciadv.adr9092
Source: www.sci.news
