Coherent light scattering by blue feather barbs

摘要: The structural colours of avian feather barbs are created by the scattering light from spongy matrix keratin and air in medullary layer barbs1,5. However, precise physical mechanism for production these is still controversial1,3,4,6. Here we use a two-dimensional (2D) Fourier analysis spatial variation refractive index blue plum-throated cotinga (Cotinga maynana, Cotingidae) to show that colour produced constructive interference between waves scattered coherently nanostructured keratin-air barbs.