An optical identification element 8 includes an optical substrate 10 having at least one diffraction grating 12 disposed therein. The grating 12 has a one or more of colocated pitches A which represent a unique identification N bit digital code that is detected when illuminated by incident light 24....http://www.google.es/patents/US20040233485?utm_source=gb-gplus-sharePatente US20040233485 - Diffraction grating-based optical identification element
Diffraction grating-based optical identification element
Número de solicitud: 10/661,234 Número de publicación: US 2004/0233485 A1 Fecha de presentación: 12 Sep 2003 Patente emitida: US7106513 ( Fecha de emisión 12 Sep 2006)
