Bringing Visual “Magic” to Light

Scientists create widely controllable ultrathin optical components that allow virtual objects to be projected in real environments.

The Science

Two new silicon-based optical metasurfaces are more versatile and offer more control over light than previous designs. For the first time, a material can manipulate light over wide angles while maintaining efficiency across the visible light spectrum. To create the surfaces, industrial experts used resources at the Molecular Foundry. The Molecular Foundry is a U.S. Department of Energy Office of Science user facility.

The Impact

Imagine being able to mix virtual images with your actual surroundings in real time. Such technology could benefit education, health care, public safety, entertainment and more. Building such technologies requires controlling light. The metasurfaces offer a new, versatile way to control and enhance the light-bending properties of materials.

Summary

Scientists from mixed reality technology company Magic Leap Inc., working with researchers at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), have developed new, versatile ways to control and enhance the light-bending properties of human-made optical nanostructures. Magic Leap’s technology creates visualizations that allow virtual imagery to coexist and interact with a viewer’s actual surroundings in real time. The new technology relies on “optical metasurfaces,” which are two-dimensional structures engineered to interact with light waves in ways that natural materials cannot. The materials can have layers that are a few billionths of a meter (nanometers) thick, and contain nanoscale optical antennas that can control the reflection or transmission of light. Their ultrathin nature makes them easy to integrate into a variety of systems.

Previous designs of metasurfaces that can control ultra-compact beams of light have been functional, but limited in terms of efficiency, input angle and wavelength. The team from Magic Leap created the new metasurfaces by partnering with nanofabrication experts at the Molecular Foundry, which specializes in tools and techniques for nanoscale research and development. They carved a pattern of silicon nanobeams using a focused beam of electrons and then transferred the design onto an ultrathin layer of silicon, only about 20 to 120 nanometers in thickness. These nanobeams were arranged to control either the transmission or reflection of light. The size and spacing between the nanobeams control the properties of the exiting light. By making the metasurfaces out of silicon, the researchers took advantage of the extensive fabrication technology that is widely available for this material, which allows their work to be more easily scaled up to mass production.

Contact

Stefano Cabrini
Molecular Foundry, Berkeley Lab
[email protected], 510-486-7339

Funding

Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under contract DE-AC02-05CH11231.

Publications

D. Lin, M. Melli, E. Poliakov, P. St. Hilaire, S. Dhuey, C. Peroz, S. Cabrini, M. Brongersma, and M. Klug, “Optical metasurfaces for high angle steering at visible wavelengths.” Scientific Reports 7 (2286), 1-8 (2017). [DOI: 10.1038/s41598-017-02167-4]