Optical device exhibiting color shift upon rotation

摘要

An optical device exhibiting a color shift upon rotation is disclosed. The optical device has a textured surface having a relief structure finer than a human eye resolution but large enough not to exhibit diffraction effects. The textured surface is coated with an interference thin film that exhibits a color shift with tilt. A uniform color seen at one angle of rotation changes to another uniform color when the optical device is rotated in its own plane. A method of manufacturing of such an optical device, as well as the use of the optical device as an optical security and authentication element, is also disclosed.