OPTICAL ARTICLE HAVING DIRECTIONAL MICRO- OR NANOSTRUCTURED THIN FILM COATING, AND ITS PROCESS

摘要

The present invention concerns an optical article comprising a substrate with a front main face and with a rear main face, at least one of the main faces being coated with a columnar micro/or nano-structured coating, wherein the substrate and the optical article are transparent or can be put in a state where they are transparent in at least a part of the visible region ranging from 380 to 780 nm, along at least one incidence angle; said columnar micro- or nano-structured coating comprises at least an array of columns comprising each and an upper layer covering said core, the core and the upper layer being structurally and/or chemically different and have light absorbing properties or can be put in a state where they have light absorbing properties with an extinction coefficient "K" equal to or higher than 10^-2 in at least a part of the light spectrum ranging from 250 to 2500 nm and are able to cause a change in transmission or in reflection of incident light through the optical article as a function of the angle of incidence light. The invention concerns also a method for manufacturing an optical article comprising a columnar micro- or nano-structured coating.