An optical structure includes a light transmissive substrate having a surface relief pattern applied thereon, such as a hologram. One or more layers can be patterned corresponding to materials playing the role of absorbers or reflectors on a Fabry-Perot type of optical structure. These materials are...http://www.google.ca/patents/US7667895?utm_source=gb-gplus-sharePatent US7667895 - Patterned structures with optically variable effects
