PhD ceremony mr. B.D. Wilts: Brilliant biophotonics. Physical properties, pigmentary tuning & biological implications

PhD ceremony: mr. B.D. Wilts, 14.30 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Brilliant biophotonics. Physical properties, pigmentary tuning & biological implications

Promotor(s): prof. H.A. de Raed, prof. D.G. Stavenga

Faculty: Mathematics and Natural Sciences

Millions of years of evolutionary history has led to the amazing diversity of biological organisms present nowadays that make use of different coloration mechanisms to reflect bright colors. The most brilliant and dazzling colors as well as the whitest whites and blackest blacks of many animals, such as birds, beetles and butterflies, arise from the physical interaction of light with ordered, quasi-ordered and disordered matter, resulting in structural colors. These biophotonic nanostructures can vary in complexity, ranging from ‘simple’ multilayered structures to topologically complex, three-dimensional photonic crystals. The photonic structures alter the spectral composition of incident light and so create the striking colours. In this thesis, I have investigated a range of photonic structures in birds, beetles and butterflies and investigated in detail how these complex shaped structures interact with incident light. I further investigated how these structural colors can be tuned due to the presence of absorbing pigment filters. By applying a gamut of different physical techniques, I thereby gained insight into the optical properties of these complex shaped composites of structural and pigmentary colors. The biological functions of these displays, ranging from intersexual signalling to camouflage, are discussed.