Professor Anatoly Zayat’s and Dr Alex Minovich from King’s College London have developed new 2D nano-surfaces which appear as realistic 3D objects – including shading and shadows – using cutting edge nano-engineering. The research was carried out alongside Rheinische Friedrich-Wilhelms-Universität Bonn, and is published in the American Chemical Society journal Nano Letters.
When light hits an object, the colour, texture, and shape affect how light is absorbed and reflected, allowing you to make out the object in front of you. By altering the surface to change how light is reflected, it is possible to manipulate how it appears.
The researchers developed layered materials, incorporating precisely designed nano-features smaller than the wavelength of light – called metasurfaces. This allowed them to control how light is reflected in highly precise ways, so that a 2D surface reflects light just as a 3D object would.
Borrowing a technique from 3D graphics called Normal Mapping, researchers encoded shadow effects into the image, creating 3D images more realistic than holograms or 3D cinema. As a proof of concept, the researchers fabricated a flat metasurface imitating lighting and shading effects of a 3D cube.
The technique could have huge implications for the optical industries, including in TV screens and photography.
Professor Anatoly Zayats of King’s College says: “Metasurfaces are amazing. They open up unprecedented freedom in directing and manipulating light. One might ultimately imagine a TV screen which appears exactly the same as you move around it, or a new movement of 3D art”.
The ability to control light could bring new functionality to small camera lenses. A flat surface can be made to appear optically convex by designing appropriate metasurface properties. Future generations of smartphone cameras could use the tiny flat metasurfaces which mimic the properties of sophisticated curved camera lenses, allowing much greater control of angle and depth field.
The wafer thin materials could also replace heavy optical lenses in applications such as satellites, where weight and size have a big impact on efficiency.
More immediately, the novel nano-materials could already be used to create unique complex 3D images for security and anti-counterfeiting applications, as well as for new measurement applications requiring precise control of light.