摘要

Security and safety of people, goods and environment cover a large range of societal concerns from people identification to medical diagnostic, driving assistance or pollution control, for which vision and photonic technologies are at the heart of key innovative industrial developments. In this presentation, we will introduce a recently labeled Erasmus Mundus Joint Master Degree starting in September 2020. This master degree gathers the most influential academic and industrial actors in Photonics for Security, Reliability and Safety through four main European universities in France, Italy and Finland supported by experts from 24 leader companies and more than 20 academic associated partners, among which SJTU. The first part of the presentation will give an overview of the program objectives and organization and will present the research expertise among the full partners. The second part will be dedicated to recent advances in the field of security features for ID documents carried out at the Graduate School MANUTECH SLEIGHT, France.

Hiding several images in a single printing, which appear selectively under different angles of observation, is of great interest for applications to security, data storage or design. Several techniques have been developed for this purpose, based on holography, moiré methods, multiple laser image (MLI) systems or on the use of dichroic plasmonic colors [1-2]. A technology combining plasmonic metasurfaces and laser scanning processes is presented here. It provides a simple implementation for printing multiplexed images with high flexibility and a micrometric spatial resolution. It is based on the shaping by femtosecond or nanosecond laser pulses of metallic Ag nanoparticles within thin TiO2 films and the triggering of self-organization mechanisms that lead to very regular periodic patterns controlled at the sub-wavelength scale. Here, we present the main physico-chemical mechanisms [3] that contribute to the shaping of plasmonic films at the nanometer and micrometer scales and we show how such a laser technology allows engineering dichroic colors [4] and reinventing multiple laser image printing with self-organized gratings [5] and image multiplexing with up to three different images printed in the same set of pixels.

[1] E. Heydari, J. R. Sperling, S. L. Neale and A. W. Clark, Plasmonic Color Filters as Dual‐State Nanopixels for High‐Density Microimage Encoding, Adv. Funct. Mater., 2017, 27, 1–6.

[2] X. M. Goh, Y. Zheng, S. J. Tan, L. Zhang, K. Kumar, C. W. Qiu and J. K. W. Yang, Three-dimensional plasmonic stereoscopic prints in full colour, Nat. Commun., 2014, 5, 5361.

[3] Z. Liu, J. Siegel, M. Garcia-Lechuga, T. Epicier, Y. Lefkir, S. Reynaud, M. Bugnet, F. Vocanson, J. Solis, G. Vitrant, N. Destouches, "3D self-organization in nanocomposite layered systems by ultrafast laser pulses", ACS Nano, 2017, 11 (5), 5031–5040.

[4] N. Sharma, N. Destouches, C. Florian, R. Serna, J. Siegel, "Tailoring nanocomposite materials with ultrashort laser pulses for applications in photonics", Nanoscale, to be published

[5] N. Sharma, M. Vangheluwe, F. Vocanson, A. Cazier, M. Bugnet, S. Reynaud, A. Vermeulin, N. Destouches, "Laser-driven plasmonic gratings for multiple image hiding", Materials Horizons, 2019, 6, 978.

报告人简介

Nathalie Destouches is professor at University Jean Monnet in Saint-Etienne, France, where she leads a research team that develops new generations of visual security features based on laser-processed plasmonic metasurfaces, carries out multiscale time-resolved experiments and implements multiphysical modeling to better understand and describe light interaction with plasmonic metamaterials. She received her Ph.D. in Optics and Photonics from Aix-Marseille University in 2001 and got experience in surface science during a post-doc at the Laboratory of Glass. Today, her lab expertise includes laser processing, characterization and modelling of laser-matter interaction, micro and nano-structuring and optical properties, metamaterials, electromagnetic modelling. She led three ANR (National Research Agency) projects, one being featured by the ANR in the field of nanoscience in 2017, and several industrial and academic projects. She also coordinates the Master Optics Image Vision Multimedia of Univeristy of Lyon.

https://perso.univ-st-etienne.fr/destoucn/