Photonic Band Gap Crystals from Biological Structures

The strikingly colorful world of insects is in large part the result of optical interference produced by the interaction of light with precisely ordered, periodic bio-polymeric structures, incorporated into their exoskeletons. Such structural colors have recently gained tremendous interest for the use as photonic crystals with promising potential for energy and information technology applications. While our current photonic engineering capabilities at visible wavelengths are rather limited, biological systems have evolved to create the most complex photonic architectures – structures that are still far out of our synthetic reach. For example, we discovered recently that the brilliant coloration of several beetles is the result of photonic structures with a diamond-based lattice – one of the most efficient photonic architectures. I will also present bio-templating fabrication routes that take advantage of the synergistic combination of photonic engineering in biology with sol-gel chemistry-based materials synthesis. Using this approach, we create high-dielectric three-dimensional photonic crystals with a variety of lattice geometries and band gaps at visible frequencies. In order to evaluate the properties of these novel photonic architectures, we apply a range of structural and optical characterization tools, including multi-directional optical reflectance micro-spectroscopy, optical and electron microscopy as well as photonic band structure calculations.

Prof Bartl's website is http://www.chem.utah.edu/faculty/bartl/