Beams of light that can be shaped into corkscrew-like forms, known as optical vortices, are used today in a variety of applications. Pushing the boundaries of structured light, applied physicists at Harvard’s John A. Paulson School of Engineering and Applied Sciences (SEAS) have reported a new type of optical vortex beam. This beam not only twists as it travels but also changes at different rates in different regions, creating unique patterns. Its behavior resembles the spiral shapes often seen in nature.
Drawing from classical mechanics, the researchers nicknamed their never-before-demonstrated light vortex an “optical rotatum” to describe how the torque on the light’s corkscrew shape gradually changes. In Newtonian physics, “rotatum” refers to the rate of change in torque on an object over time.
The optical rotatum was created in the lab of Federico Capasso, the Robert L. Wallace Professor of Applied Physics and the Vinton Hayes Senior Research Fellow in Electrical Engineering at SEAS. “This is a new behavior of light consisting of an optical vortex that propagates through space and changes in unusual ways,” Capasso said. “It is potentially useful for manipulating small matter.” The research is published in Science Advances.
To read more, click here.