A strange new world of light

Structured light

Over the past ten years, the physical developed nanostructured materials that can produce light beams completely out of the standard, which exhibit unusual behaviors such as spiral bending , corkscrew shape or that share as a Y .

These so-called structured light beams are not only revealing unknown things about the physics of light, they also have a wide range of practical applications, from super resolution images to microscopes and telescopes, to light-beam molecular manipulation and communications. by light without optical fibers.

Now researchers have developed a tool that generates new, more complex light states in a completely different and configurable way.

"We have developed a metasurface that is a new tool for studying unpublished aspects of light. This optical component enables much more complex operations and allows researchers to not only explore new states of light but also new applications for structured light," said the professor. Federico Capasso, from Harvard University, USA.

Angular momentum and polarization

The metasurface connects two aspects of light: orbital angular momentum and circular polarization (or angular rotation pulse). In comparison to a planet, orbital momentum describes how the planet orbits the sun and circular polarization describes how the planet rotates about its own axis (rotation).

Light bias could already be used to control the size and shape of these exotic beams, but the connection was limited because only certain polarizations could be converted at certain orbital moments.

The new metamaterial significantly widens this connection. It can be designed so that any input bias can result in any orbital angular momentum output. In other words, any polarization can produce any kind of structured light, from spirals and corkscrews to vortices of any size.

Another great advantage is that the metasurface is multifunctional and can be programmed so that a polarization results in one vortex and a different polarization results in another completely different vortex.

Examples of structured light showing cross sections of beams.


Potential applications of this device include molecular manipulation and optical tweezers, which use light to move molecules and nanoparticles - the orbital momentum of light is strong enough to rotate and move microscopic particles.

Other fields of application include high resolution images, light beams for quantum computing, free space optical communication, and new light states in lasers.


Article: Arbitrary spin-to-orbital angular momentum of light conversion

Authors: Robert C. Devlin, Antonio Ambrosio, Noah A. Rubin, JP Balthasar Mueller, Federico Capasso

Magazine: Science

Vol .: eaao5392

DOI: 10.1126 / science.aao5392

Post a Comment

Previous Post Next Post