Engineers have developed a new method called dewetting for producing glass metasurfaces that can be rigid or flexible. It is a natural process that occurs when a thin film of material is deposited on a substrate and then heated, is used in the new method. The heat causes the film to shrink and disintegrate into tiny nanoparticles.
The new method could fabricate all-dielectric optical metasurfaces quickly, at low temperatures, and without using a cleanroom. These metasurfaces have the potential to be used to create next-generation photonic circuits. Optical circuits, which are 10 to 100 times faster and more energy-efficient than electronic circuits, have the potential to transform the performance of many devices.
Instead of metallic metasurfaces, they used dewetting to create dielectric glass metasurfaces. They began by creating a substrate textured with the desired architecture. The chalcogenide glass material was then deposited in thin films only tens of nanometers (nm) thick. The substrate was heated for a few minutes until the glass became fluid and nanoparticles formed in the sizes and positions dictated by the texture of the substrate.
Dewetting has never been used to create glass metasurfaces before. The metasurfaces are smooth and regular. It is possible to produce them quickly on large surfaces and flexible substrates.