@inproceedings{54fd2e703d3142bf98485f5c185fe3ee,
title = "UV scattering by pores in avian eggshells",
abstract = "Eggshell is essential for the reproduction of birds. The optical properties of their shells may have an impact on biological functions such as heat and UV protection, recognition by the parents or camouflage. Whereas ultraviolet reflection by bird eggshells has been superficially described in the scientific literature, the physical origin of this phenomenon remains poorly understood. In this article, reflectance peaks in the near UV range were observed by spectrophotometric measurements of hen eggshells. In addition, electron microscopy imaging revealed the presence of pores within the so-called {"}calcified shell{"}part (i.e., between ca. 20 μm and ca. 240 μm deep from the outer surface). The average radii of these pores range from 120 to 160 nm. Mercury intrusion porosimetry allowed to highlight a distribution of pore radii around 175 nm. Numerical and analytical predictions using scattering theory indicate that these pores are responsible for the optical response observed in the UV range. ",
keywords = "Avian eggshell, Cuticle, Eggshell, Nanostructure, Natural photonic structures, Photonics, Ultraviolet radiation, Ultraviolet reflectance, UV scattering",
author = "M. Ladouce and T. Barakat and Su, {B. L.} and O. Deparis and Mouchet, {S. R.}",
note = "Funding Information: The authors thank C. Charlier (Electron Microscopy Service, UNamur) for technical support during electron microscopy observations, respectively. S.R.M. was supported by the Belgian National Fund for Scientific Research (FRS-FNRS) as a Postdoctoral Researcher (91400/1.B.309.18F). This research was also supported by FRS-FNRS through the Researchers{\textquoteright} Credit CC 1.5075.11F. This research used resources of the Technological Platform High Performance Computing (PTCI) (http://www.ptci.unamur.be) located at UNamur and the resources of the Electron Microscopy Service (SME) of UNamur (http://www.unamur.be/en/sevmel). PTCI is supported by FNRS-FRFC, the Walloon Region and UNamur (Conventions No. 2.5020.11, GEQ U.G006.15, 1610468 and RW/GEQ2016). PTCI and SME are members of the {"}Consortium des {\'E}quipements de Calcul Intensif (C{\'E}CI){"} (http://www.ceci-hpc.be) and the Technological Platform Morphology - Imaging (MORPH-IM) of UNamur, respectively. Publisher Copyright: {\textcopyright} 2020 SPIE. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.; Light in Nature VIII 2020 ; Conference date: 24-08-2020 Through 04-09-2020",
year = "2020",
month = aug,
day = "21",
doi = "10.1117/12.2567915",
language = "English",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Vasudevan Lakshminarayanan and Katherine Creath and Shaw, {Joseph A.}",
booktitle = "Light in Nature VIII",
}