Outstanding 3D images from flat surfaces

Adapting a technique from 3D computer graphics, researchers from King's College London, working with colleagues at Rheinische Friedrich-Wilhelms-Universität Bonn, have developed flat surfaces which appear as realistic 3D objects in normal illumination. The technique involves engineering features into the surface that are smaller than the wavelength of light, which controls how light is reflected by the surface.

The King’s team claims that the images encoded onto its surfaces — known as metasurfaces — are more realistic than holograms or the current state of the art in 3D cinema; but unlike holograms, which need a laser to be viewed, these metasurfaces work under conventional lighting or daylight. As well as having potential for new forms of 3D art and in marking items for security purposes, metasurfaces such as these could enable the construction of devices to replace heavy and bulky lenses in satellites and in portable electronic devices, they add.

The research used a technique borrowed from a 3D computer graphics technique called normal mapping, which simulates how light and shade changes on a solid object when an illumination source is moved. To test the concept, the team fabricated a layered metasurface that imitated the lighting ands shading effects of the surfaces of a solid cube, as they explain in the American Chemical Society journal Nano Letters.