A multidisciplinary approach involving three lines of research were developed in parallel within the PHENOmenon Project:
i) Materials and Photochemistry: New complete chemical systems were developed (resins, photoinitiators, sensitizers), to control the characteristics of the fabricated optostructure, and the mechanism of the optical writing. CNRS explored cost effective and environmentally friendly synthesis routes to obtain the required materials with new optical properties, like high refraction index materials (n>2).
ii) Laser Writing: development and realization of new and unique laser writing setups to realize the concept of Massively Parallelized Laser Writing. The strategies include diffractive optical elements (DOEs), dynamic amplitude and phase modulation (with SLM devices like LCOS or LCDs), and holographic projection. IMT-A designed the optical elements which allow for massive parallelization (up to 100k simultaneous individually addressed voxels). The parallelization strategies were tested at laser writing facilities of different partners (AIMEN, IMT-A, CNRS, MPO), and the results were complemented with wafer level postprocessing (THALES).
iii) Advanced nano-optostructured optical system design: modelling and design of functional optostructures with sub-wavelength features, with the development of the wave propagation models at nanostructure level, and its link with micro, meso and macroscale model and design frameworks. The project started from existing tools and developments in the consortium partners (THALES, FLUXIM, IMT-A, ICFO, CNRS), further developing the models to fit the characteristics of the target microstructures, and fitting together the models to make them compatible. The project has already resulted in a new version of the LAOSS software by FLUXIM, to successfully deliver the designs for ultraflat microlenses, nanostructured concentrator Fresnel optics, and a flat microprism based optostructured diffuser layer for finetuned LED backlighting. Novel approaches were proposed to calculate and design color 3D holograms reconstructed with white LEDs or natural light, and different 3D effects.
The demonstration of the technology was carried out through the combination of the achievements of the three lines of research. In this way, the fabrication of five challenging products was reached: antifogging optics for surveillance (THALES), machine readable color holograms (FNMT), holographic virtual button (PSA), high visibility curved display (FLEXENABLE) and ultraflat LED lighting surfaces (DLED); analyzing the outcome of the fabrication against benchmarks established based on the characteristics and performance of existing state of the art equipment and praxis.
