Counterfeit-Deterrents for Surface-Relief Diffractive Optical Elements

Abstract

Surface-relief diffractive optical elements (DOEs) have a wide range of applications in present-day optical systems. DOEs have been used for the achromatization, color-correction, and athermalization of imaging systems. Diffractive phase plates are used as fanout gratings in optical interconnect and laser machining applications. Phase plates are also prevalent in display and alignment applications whereby they are used to generate arrows, company logos, and grids and lines, respectively. The ability to design and fabricate high-quality, precision, surface-relief, DOE masters requires a high level of intellectual property in addition to sophisticated manufacturing infrastructure. However, once a high-quality DOE is produced, it is an easier task to produce polymer replicas of the surface using technologies such as cast-and-cure, embossing, and injection molding.[1] The technology to perform high-quality replicas of DOE surfaces is becoming more prevalent globally. As the volume of surface-relief DOEs inserted into the marketplace increases, one must consider measures to deter unauthorized reproductions of one’s intellectual property. Counterfeiting is a $50 billion dollar a year business,[2] and although most of the items counterfeited include computer hardware and software, clothing, and perfume, DOEs, as their market-presence increases, will attract counterfeiters.