Identification of objects using plasma resonant particles

Abstract

A method and apparatus for identifying an object having a pattern of plasmon resonant particles (PREs) distributed in or on the object are disclosed. In the method, a field containing the pattern is illuminated, and one or more spectral emission characteristics of the light-scattering particles in the field are detected. From this data, an image of positions and spectral characteristic values in the field is constructed, allowing PREs with a selected spectral signature to be discriminated from other light-scattering entities, to provide information about the field. The image may be compared to a database of reference images to identify or validate the object.

1 . A device for identifying an object, comprising:
 a film comprising a pattern of plasmon resonant entities (PREs) deposited on at least a portion of a surface of the object, wherein the pattern of PREs produces an image comprising detectable spectral emissions when excited with a light source, wherein the image corresponds to one or more reference images stored within a database, and wherein the object is identified when the image is compared to and matches the one or more reference images.   
     
     
         2 . The device of  claim 1 , wherein the pattern is random. 
     
     
         3 . The device of  claim 1 , wherein the pattern is pre-defined. 
     
     
         4 . The device of  claim 1 , further comprising a protective coating on top of the film. 
     
     
         5 . The device of  claim 1 , further comprising a data storage medium disposed within the object, wherein the data storage medium has data stored therein corresponding to a coded version of the pattern. 
     
     
         6 . A system for identifying an object, comprising:
 a film comprising a pattern of plasmon resonant entities (PREs) deposited on at least a portion of a surface of the object;   a light source adapted to excite plasmon resonance in the PREs;   a detector for detecting spectral emissions of the PREs within the pattern and generating an image corresponding to the pattern;   a processor for comparing the image with one or more reference images stored within an image database, wherein the one or more reference images are associated with one or more potential identities of the object; and   an indicator for generating an indication of an identity of the object.   
     
     
         7 . The system of  claim 6 , wherein the object comprises an item subject to forgery. 
     
     
         8 . The system of  claim 6 , wherein the object comprises currency. 
     
     
         9 . The system of  claim 6 , wherein the object comprises a credit card. 
     
     
         10 . The system of  claim 6 , wherein the object comprises an identification document. 
     
     
         11 . The system of  claim 6 , wherein the pattern is random. 
     
     
         12 . The system of  claim 6 , wherein the pattern is pre-defined. 
     
     
         13 . The system of  claim 6 , further comprising a data storage medium disposed within the object, wherein the data storage medium has data stored therein corresponding to a coded version of the pattern. 
     
     
         14 . The system of  claim 6 , wherein the indication of an identity of the object comprises a signal indicating validity of the object.