CODING AND AUTHENTICATION BY PHASE MEASUREMENT MODULATION RESPONSE AND SPECTRAL EMISSION

摘要

A method of coding and authentication includes the steps of irradiating a sample (20) with a harmonically modulated radiation source (15), and measuring with a detector (30) a component of the emission of the sample (20) where the component is out of phase with the radiation. The method further includes modulating the intensity of the radiation and identifying the sample (20) by a phase difference between the radiation and the out of phase component.