Method and device for controlling the color of metals

Abstract

A method and a device are disclosed for changing the color of a metal surface in a given part of the electromagnetic spectrum. It is achieved by creating a surface relief as an array of raised or indented repeated elements without breaking the continuity of the metal surface. The characteristic size of the elements is smaller than the shortest wavelength in that part of spectrum. In particular, the method uses excitation of surface plasmons on the metal surface. The relief may be optionally covered by a layer of dielectric or semiconductor for further fixed or externally controlled change of the metal surface color. The device may be used to detect the intensity or color or phase of incident light. It may be used to detect another substance in proximity of the surface by changing the color or phase or intensity of reflected light.

Dependencies are inferred from the claim text.