caa a22 4500 463213882 CHVBK 20180405153150.0 cr unu---uuuuu 170326e20070101xx s 000 0 eng 10.1007/s00339-006-3723-9 doi (NATIONALLICENCE)springer-10.1007/s00339-006-3723-9 Multiscaled polarization effects in Suneve coronata (Lepidoptera) and other insects: application to anti-counterfeiting of banknotes [Elektronische Daten] [S. Berthier, J. Boulenguez, Z. Bálint] The scales of many Lepidoptera and the elytra of quite a number of Coleoptera possess specialized micro- and nano-structures that produce special polarization effects. They are constituted by concave multilayered cavities. This leads to two different effects: (1) interferential non-polarized coloration by reflection near normal incidence in the middle of the cavities and (2) polarized interferential colouration at lower wavelength after double reflection near the Brewster incidence at the periphery of the cavities. The macroscopic appearance resembles the "pointillist effect” with one of the component polarized while the other one is not. The first one can be extinguished with linear polarizer so that the colour is modified. In most insects, the structure is locally symmetric; hence, no macroscopic effects can be seen. In certain species, this symmetry is partly broken, and a slight effect can be observed. In the wing dorsal surface of the fascinating neotropical butterflies genus Suneve, perpendicular structures of two different kinds in size polarize the reflected light. The larger one is constituted by the convex cover scales whose apex falls perpendicularly on the bases of the following scales, creating long polarized valley (50μm width) transversally running across the wing. The smaller one is constituted by the ridges of the scales (2μm apart) that polarize light in the perpendicular direction. Adapted multilayered structures can be deposited onto banknotes to create anti-counterfeiting patterns as a further development of protection and security. Different effects can be produced by the use of such structures. (1) Changes of luminosity: A specific pattern will be constituted by two different areas: one with horizontal concave multilayered structures, and the other one with vertical structures. Under unpolarized light, the reflected spectra of these different areas are identical and no pattern appears. Under polarized light, i.e., through a linear polarizer, one or the other area is partly extinguished, according to the orientation of the polarizer, and the pattern appears. (2) Changes in colours: a compound colour can be produced by the juxtaposition of planed and grooved surfaces. Due to the change of incidence of the incoming light, the colours of these two zones are different, but that produced by the first one is unpolarized while the second one is partly polarized and can be modified with a linear polarizer. Springer-Verlag, 2006 Berthier S. Institut des Nano-Sciences de Paris, UMR 7588, CNRS, Université Pierre et Marie Curie - Paris 6, 140 rue de Lourmel, 75015, Paris, France aut Boulenguez J. Institut des Nano-Sciences de Paris, UMR 7588, CNRS, Université Pierre et Marie Curie - Paris 6, 140 rue de Lourmel, 75015, Paris, France aut Bálint Z. Hungarian Natural History Museum, Baross utca 13, 1088, Budapest, Hungary aut Applied Physics A Springer-Verlag 86/1(2007-01-01), 123-130 0947-8396 86:1<123 2007 86 339 https://doi.org/10.1007/s00339-006-3723-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00339-006-3723-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Berthier S. Institut des Nano-Sciences de Paris, UMR 7588, CNRS, Université Pierre et Marie Curie - Paris 6, 140 rue de Lourmel, 75015, Paris, France aut NATIONALLICENCE 700 1- Boulenguez J. Institut des Nano-Sciences de Paris, UMR 7588, CNRS, Université Pierre et Marie Curie - Paris 6, 140 rue de Lourmel, 75015, Paris, France aut NATIONALLICENCE 700 1- Bálint Z. Hungarian Natural History Museum, Baross utca 13, 1088, Budapest, Hungary aut NATIONALLICENCE 773 0- Applied Physics A Springer-Verlag 86/1(2007-01-01), 123-130 0947-8396 86:1<123 2007 86 339 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer