Science Daily March 17, 2022
Researchers in South Korea have developed an optical encryption platform that works simultaneously in the visible and ultraviolet (UV) regimes. They adjusted the physical properties of silicon nitride to reduce its tendency to absorb ultraviolet light. They fabricated a metahologram in which an image clearly appears when ultraviolet laser is irradiated on it. They combined the two metaholograms that work in the ultraviolet and visible light regions to create an anticounterfeiting device that displays a unique product number. The hologram that appears when a visible light laser is irradiated acts as a key and when this key information is input into the ultraviolet polarizer and irradiated with ultraviolet light, unique numbers disappear. The system is difficult to decrypt because it uses the invisible ultraviolet light and reduces the chances of exposing the password or the code that can confirm forgery or falsification…read more. TECHNICAL ARTICLE
Graphic abstract. Credit: ACS Nano 2022, XXXX, XXX, XXX-XXX, February 19, 2022Â