An optical identification element for identifying an item. The optical identification element includes a binder material and one or more materials embedded in the binder material. The one or more materials provides an encoded composite X-ray diffraction pattern when illuminated by an X-ray beam. The...http://www.google.com.au/patents/US7623624?utm_source=gb-gplus-sharePatent US7623624 - Method and apparatus for labeling using optical identification elements characterized by X-ray diffraction
Method and apparatus for labeling using optical identification elements ...
