Controlling the Colour of Metals: Intaglio and Bas-Relief Metamaterials

摘要

The fabrication of indented ('intaglio') or raised ('bas-relief')sub-wavelength metamaterial patterns on a metal surface provides a mechanismfor changing and controlling the colour of the metal without employing any formof chemical surface modification, thin-film coating or diffraction effects. Weshow that a broad range of colours can be achieved by varying the structuralparameters of metamaterial designs to tune absorption resonances. This novelapproach to the 'structural colouring' of pure metals offers great versatilityand scalability for both aesthetic (e.g. jewellery design) and functional (e.g.sensors, optical modulators) applications. We focus here on visible colour butthe concept can equally be applied to the engineering of metallic spectralresponse in other electromagnetic domains.