Downloadable Papers
Here is a selection of papers in pdf format available for download. If you would like copies of our other papers, please contact us
Brilliant Whiteness in Ultrathin Beetle Scales
Science, Vol 315, p 348, 19 January 2007
Pete Vukusic, Benny Hallam and Joseph Noyes
Abstract: The colored appearances of animals are invariably controlled by pigmentation, highly periodic ultrastructure, or a combination of both. Whiteness, however, is less common and is generated by neither of these methods, because it requires scattering processes appropriate for all visible wavelengths. We report the identification of whiteness resulting from a three-dimensional (3D) photonic solid in the scales of Cyphochilus spp. beetles. Their scales are characterized by their exceptional whiteness, their perceived brightness, and their optical brilliance, but they are only 5 mm thick. This thickness is at least two orders of magnitude thinner than common synthetic systems designed for equivalentquality whiteness.
Complete article (pdf)
Full article on the Science Web Site
Directionally Controlled Fluorescence Emission in Butterflies
Science, Vol 310, p 1151, 18 November 2005
Pete Vukusic and Ian Hooper
Abstract: In synthetic optical emitters such as lightemitting diodes (LEDs), the majority of generated light is trapped internally. Recently developed high-efficiency devices, however, use two-dimensional (2D) photonic-crystal geometries to enhance the extraction efficiency of light, and the devices also use distributed Bragg reflectors (DBRs) to control emission direction. Here we detail the elaborate optical emission system on the wing scales of a small group of butterflies. Their scales comprise a pigment-infused 2D photonic crystal that provides intense directed fluorescence, which is directionally enhanced by a DBR. This biological system shares many design features with high-emission LEDs.
Complete article (pdf)
Full article on the Science Web Site
Photonic Structures in Biology
Nature, Vol 424, p 852-855, 14 August 2003
Pete Vukusic and J. Roy Sambles
Abstract: Millions of years before we began to manipulate the flow of light using synthetic structures, biological systems were using nanometre-scale architectures to produce striking optical effects. An astonishing variety of natural photonic structures exists: a species of Brittlestar uses photonic elements composed of calcite to collect light, Morphobutterflies use multiple layers of cuticle and air to produce their striking blue colour and some insects use arrays of elements, known as nipple arrays, to reduce reflectivity in their compound eyes. Natural photonic structures are providing inspiration for technological applications.
Complete article (pdf)
Full article on the Nature Web Site
Now you see it - now you don't
Nature, Vol 410, p 36, March 2001
P. Vukusic, J. R. Sambles, C. R. Lawrence, R. J. Wootton
Abstract: The dazzling iridescence seen in some hummingbirds and tropical butterflies arises from natural optical phenomena, the brightest of which originate in nanoscale structures that produce ultrahigh reflectivity and narrow-band spectral purity. Here we investigate the coloration of male Ancyluris meliboeus Fabricius butterflies, which have patches of unusual microstructure on their ventral wing scales. We find that this highly tilted, multilayered arrangement produces a bright iridescence of broad wavelength range and generates a strong flicker contrast from minimal wing movement.
Complete article (pdf)
Article on the Nature Web Site
Sculpted-multilayer optical effects in two species of Papilio butterfly
Applied Optics, Vol 40, pp 1116-1125, March 2001
P. Vukusic, J. R. Sambles, C. R. Lawrence, R. J. Wootton
Abstract:The wing-scale microstructures associated with two species of Papilio butterfly are described and characterized. Despite close similarities in their structures, they do not exhibit analogous optical effects. With Papilio palinurus, deep modulations in its multilayering create bicolor reflectivity with strong polarization effects, and this leads to additive color mixing in certain visual systems. In contrast to this, Papilio ulysses features shallow multilayer modulation that produces monocolor reflectivity without significant polarization effects.
Complete article (pdf)
Full article on the Optics Express Web Site
Colour mixing in wing scales of a butterfly
Nature, Vol 404, p 457, March 2000
P. Vukusic, J. R. Sambles, C. R. Lawrence
Abstract:Green coloration in the animal kingdom, as seen in birds' feathers and reptile integument, is often an additive mixture of structurally effected blue and pigmentary yellow1. Here we investigate the origin of the bright green coloration of the wing scales of the Indonesian male Papilio palinurus butterfly, the microstructure of which generates an extraordinary combination of both yellow and blue iridescence. The dual colour arises from a modulation imposed on the multilayer, producing the blue component as a result of a previously undiscovered retro-reflection process.
