title: Discovery of a diamond-based photonic crystal structure in beetle scales.
abstract: We investigated the photonic crystal structure inside iridescent scales of the weevil Lamprocyphus augustus. By combining a high-resolution structure analysis technique based on sequential focused ion beam milling and scanning electron microscopy imaging with theoretical modeling and photonic band-structure calculations, we discovered a natural three-dimensional photonic structure with a diamond-based crystal lattice operating at visible wavelengths. Moreover, we found that within individual scales, the diamond-based structure is assembled in the form of differently oriented single-crystalline micrometer-sized pixels with only selected lattice planes facing the scales' top surface. A comparison of results obtained from optical microreflectance measurements with photonic band-structure calculations reveals that it is this sophisticated microassembly of the diamond-based crystal lattice that lends Lamprocyphus augustus its macroscopically near angle-independent green coloration.
authors.affiliation: Department of Chemistry, University of Utah, 315 South 1400 East, HEB Room 2020, Salt Lake City, Utah 84112, USA.
authors.forename: Jeremy W
authors.initials: JW
authors.lastname: Galusha
authors.forename: Lauren R
authors.initials: LR
authors.lastname: Richey
authors.forename: John S
authors.initials: JS
authors.lastname: Gardner
authors.forename: Jennifer N
authors.initials: JN
authors.lastname: Cha
authors.forename: Michael H
authors.initials: MH
authors.lastname: Bartl
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000737:chemistry* / Q000502:physiology / Q000648:ultrastructure*; D003198:Computer Simulation; D003461:Crystallography; D018130:Diamond / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D017785:Photons; D012031:Refractometry
chemical_list: D018130:Diamond