Metal-based photonic coatings from electrochemical methods

Plasmonic materials offer the remarkable ability to manipulate light by metal-dielectric features significantly smaller than the wavelengths of free space photons. The fabrication of such miniscule features for the desired plasmonic properties, however, remains challenging. Here we report an economical and versatile bottom-up approach that combines electrodeposition and dealloying techniques for fabricating elaborate metal-based structures, achieving structural resolutions comparable to current lithography techniques. We present our studies on the metal-based counterpart of the rugate filter. These metal-based photonic films are porous, magnetic, and feature strong optical responses in visible wavelengths, while their structural periodicities are an order of magnitude smaller than the light´s free space wavelength.