Scientists have developed a new type of "virtual" metasurface—capable of controlling light in ways traditional lenses and optics can't—which they say is superior to the current approach, which relies on ultrathin engineered materials. The Nottingham Trent University team says the work will help fully optimize metasurface potential for a range of real-world applications and paves the way for a move from physical to virtual platforms in nanotechnology.

Metasurfaces are many times thinner than a human hair and can bend and focus light, change its color and steer it in different directions, meaning they can replace bulky optical elements in small devices such as lenses, mirrors and filters.

While they are powerful, however, the materials and dimensions of physical metasurfaces are fixed—once built, they can't change their shape, which can limit how useful they are in real-world technologies.

The study, published in the journal Advanced Photonics Nexus, demonstrates the potential for virtual metasurfaces, which use emulated two-dimensional optical patterns on a flat surface rather than tiny physical particles.

The process uses a device called a spatial light modulator, which can control light pixel by pixel to change its shape and function faster than the blink of an eye.

Because the patterns are programmable and can change instantly, the metasurface can perform many different functions within the same device. This could include mixing colors, turning invisible infrared images visible, or acting like a lens to adjust focus.

The researchers argue that making the material "tunable" by using such synthesized metasurfaces is what is required to move metasurfaces out of laboratories and onto production lines for new technologies.

While the approach requires additional research and development, the team says it could benefit a range of technologies, spanning imaging and microscopy, quantum photonics, sensing, beam steering, semiconductor manufacturing, telecommunications and holography.

In the new study, the researchers demonstrate the technology's potential by using the approach to turn invisible infrared signals into visible pictures and adjust the images' focal lengths on demand. Conventional lenses and mirrors are unable to perform these two functions concurrently.