An optical disc for data storage includes a layer of color-shifting material. Light passing through the color-shifting layer will have a color determined by the various constructive and destructive interference of the various wavelengths after they have passed through the material, diffracted while passing...http://www.google.fr/patents/US7269123?utm_source=gb-gplus-shareBrevet US7269123 - Wavelength selective coatings for optical disc security
Wavelength selective coatings for optical disc security
