COMPOSANT OPTIQUE DE SECURITE A EFFET REFLECTIF, FABRICATION D'UN TEL COMPOSANT ET DOCUMENT SECURISE EQUIPE D'UN TEL COMPOSANT

摘要

According to one aspect, the invention relates to an optical securitycomponent intended forbeing observed under direct reflection. The component comprises a structureengraved on a layerof a material having a refraction index .eta.2, a thin layer of a dielectricmaterial having a refractionindex .eta.1 other than .eta.2, deposited on the structure, and a layer of amaterial having a refractionindex .eta.0 other than .eta.1, encapsulating the coated structure of the thinlayer. The structure has afirst pattern modulated by a second pattern such that, in at least one firstregion (61, 86), the firstpattern comprises a low-relief with a first set of facets, the shapes of whichare determined suchas to generate at least one first concave or convex cylindrical reflectiveelement, and the secondpattern forms a first subwavelength grating acting, after depositing the thinlayer andencapsulating the structure, as a first wavelength-subtractive filter; in atleast one second region(62, 86), the first pattern comprises a low-relief with a second set of facetsin which the shapesare determined such as to generate at least one concave or convex cylindricalreflective element(64), and the second pattern forms a second subwavelength grating acting,after depositing thethin layer and encapsulating the structure, as a second wavelength-subtractivefilter, separatefrom the first wavelength-subtractive filter. Each subwavelength grating canbe a zero orderdiffraction grating such as a DID.