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Reflections on iridescent neck and breast feathers of the peacock, Pavo cristatus.

Pascal FreyerBodo D WiltsDoekele G Stavenga
Published in: Interface focus (2018)
The blue neck and breast feathers of the peacock are structurally coloured due to an intricate photonic crystal structure in the barbules consisting of a two-dimensionally ordered rectangular lattice of melanosomes (melanin rodlets) and air channels embedded in a keratin matrix. We here investigate the feather coloration by performing microspectrophotometry, imaging scatterometry and angle-dependent reflectance measurements. Using previously determined wavelength-dependent refractive indices of melanin and keratin, we interpret the spectral and spatial reflection characteristics by comparing the measured spectra to calculated spectra by effective-medium multilayer and full three-dimensional finite-difference time-domain modelling. Both modelling methods yield similar reflectance spectra indicating that simple multilayer modelling is adequate for a direct understanding of the brilliant coloration of peacock feathers.
Keyphrases
  • crystal structure
  • density functional theory
  • high resolution
  • optical coherence tomography
  • molecular dynamics
  • high speed
  • mass spectrometry
  • photodynamic therapy