Patent ID: 8498052
Filing Date: 2013-07-30
Classification: G03H,G06K,G07D

Abstract:
1. A method of identifying a dispersive substance, comprising: (a) providing an item comprising the dispersive substance and an optical substrate removably attached to the dispersive substance, at least a portion of the optical substrate having a diffraction grating embedded therein or thereon, the diffraction grating having a resultant refractive index variation at a grating location indicative of a code; (b) removing the optical substrate from the dispersive substance; (c) illuminating the optical substrate with incident light after the removing, the diffraction grating providing an output light signal indicative of the code; (d) reading the output light signal from the optical substrate after the optical substrate is removed from the dispersive substance, thereby detecting the code therefrom; and (e) identifying the dispersive substance from the detected code.