Philippe Lalanne1
CNRS1
The visual appearance of flat surfaces and curved objects is paramount in life and technology for fine and applied arts.<br/>The ERC project <b>UNSEEN</b> aims at creating metasurfaces that offer new visual appearances, unseen in nature so far. The metasurfaces are composed of disordered monolayers of high-index resonant nanoparticles, either deposited from a colloidal solution on solid support or fabricated with ebeam lithography.<br/>We have developed two models to predict the scattering properties of disordered metasurfaces. They allow us to predict design the scattering properties for all wavelength and incident angles. We have validated the models by testing them with experimental data, we have also been able to design a metasurface that generate only two distinct colors (green and violet) under all incidence and viewing angles, a quite strange phenomenon if we consider that usual iridescence provides a continuous variation of color as the incident and viewing angles changes (think to a thin film). For more details on the topic, please refer to<br/>K. Vynck et al., Nat. Mater. 21, 1035–41 (2022).<br/>A. Agreda et al., ACS Nano 17, 6362–72 (2023).