Laser-driven plasmonic gratings for hiding multiple images. Issue 5 (11th March 2019)

• Record Type: Journal Article
• Authors: Sharma, N.; Vangheluwe, M.; Vocanson, F.; Cazier, A.; Bugnet, M.; Reynaud, S.; Vermeulin, A.; Destouches, N.
• Is Part Of: Materials horizons. Volume 6:Issue 5(2019)
• Page Start: 978
• Page End: 983
• Publication Date: 2019-03-11
• Subjects: Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9mh00017h
• Languages: English
• ISSNs: 2051-6347

Abstract

Abstract : Encoding diffractive images using smart laser printing for applications in security, design and data storage. Abstract : Hiding several images in a single printing, which appear selectively at different angles of observation, is of great interest for applications in security, data storage or design. Here, we propose an easy-to-implement ink-free laser-based technique to print nanostructured patterns that encode different grey-level images revealed to the eye at specific observation angles. The angular selectivity is provided by diffraction gratings whose orientation can be continuously controlled at the micrometer scale through self-organization mechanisms triggered by laser light. A diffraction yield allowing easy observation with the naked eye is demonstrated, thanks to the use of a thin TiO2 :Ag film that also prevents damage to the substrates. The technology based on laser scanning is demonstrated on transparent and flexible substrates that do not sustain high temperature. This ink-free marking technology is flexible, suited to large surfaces, rapid, and provides unique visual effects on any kind of transparent substrate.