title: Photonic polycrystal in the greenish-white scales of the African longhorn beetle Prosopocera lactator (Cerambycidae).
abstract: Three-dimensional photonic-crystal grains were found in the scales of the longhorn beetle Prosopocera lactator (Cerambycidae). The local geometric structure can be described as a face-centered-cubic array of spheres, connected by short rods, reminiscent of the "ball-and-stick" models used by solid-state chemists to visualize atomic structures. Based on scanning electron microscopy, x-ray nanotomography, optical measurements, photonic band-structure calculations, and computer simulations of the reflectance, the desaturated greenish coloration is shown to arise from the observed photonic polycrystalline structure. X-ray nanotomography is revealed as a very promising tool for photonic-crystal morphology studies.
authors.affiliation: Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), rue de Bruxelles, 61, B-5000 Namur, Belgium. jean-francois.colomer@fundp.ac.be
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Colomer
authors.forename: Priscilla
authors.initials: P
authors.lastname: Simonis
authors.forename: Annick
authors.initials: A
authors.lastname: Bay
authors.forename: Peter
authors.initials: P
authors.lastname: Cloetens
authors.forename: Heikki
authors.initials: H
authors.lastname: Suhonen
authors.forename: Marie
authors.initials: M
authors.lastname: Rassart
authors.forename: Cédric
authors.initials: C
authors.lastname: Vandenbem
authors.forename: Jean Pol
authors.initials: JP
authors.lastname: Vigneron
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000737:chemistry* / Q000648:ultrastructure*; D012031:Refractometry; D012867:Skin / Q000737:chemistry* / Q000648:ultrastructure*