Holographic color printing for optical security
Researchers from the Singapore University of Technology and Design (SUTD) have invented a new type of anti-counterfeiting technology called holographic colour prints for securing important documents such as identity cards, passports and banknotes. The research team led by Associate Professor Joel Yang demonstrated an optical device that appears as a regular colour print under white light, but projects up to three images onto a distant screen when illuminated with laser light. Unlike regular diffractive optical elements that have a frosted-glass appearance and project only single images, these new holographic colour prints would comprise a stronger deterrent to counterfeiters. In addition, the prints consist of nano-3-D-printed polymer structures and find particular use in optical document security.