Patent Number: 7,355,944

Title: Authenticatable media and method of authenticating

Abstract: One method for playing a disk, comprises illuminating a first portion of the optical article with a first laser to obtain a first optical signal, wherein the first laser has a first wavelength, illuminating a second portion with a second laser to obtain a second optical signal, wherein the second laser has a second wavelength that is different from the first wavelength, and determining if the optical article is authentic by comparing the first optical signal and the second optical signal.

Inventors: van de Grampel; Hendrik T. (Mijnsheerenland, NL), Maruvada; Sriramakrishna (Evansville, IN), Pai-Paranjape; Vandita (Evansville, IN), Potyrailo; Radislav A. (Niskayuna, NY), Schottland; Philippe (Evansville, IN), Wisnudel; Marc B. (Clifton Park, NY)

Assignee: General Electric Company

International Classification: G11B 7/00 (20060101)

Expiration Date: 2020-04-08 0:00:00