Colloidal Photonic Crystals: A convenient bottom-up platform for photonic bandgap engineering

Wednesday, September 9, 2015

12:00 pm | Hudson 208

Presenter

Dr. Koen Clays , Professor, Department of Chemistry

Photonic crystals can be considered the optical analogues of electronic semiconductor materials. Their photonic bandgap can be engineered similar to impurity doping. Colloidal nanoparticles allow for a convenient three-dimensional photonic crystal platform. We have demonstrated different approaches towards bandgap engineering, enhanced energy transfer and lasing in such self-assembled photonic crystals. Our lecture will focus on the inexpensive bottom-up approach to 3D photonic crystals offered from a physical chemistry viewpoint (in contrast to the top-down physical approach offered by lithography and etching).

Koen Clays obtained his PhD from the University of Leuven, Belgium, in 1989. He did a postdoc at the Corporate Research Laboratories of the Eastman Kodak Company, Rochester NY. He is now full professor at the Department of Chemistry at the University of Leuven, Belgium and adjunct professor at the Department of Physics and Astronomy of Washington State University, Pullman, WA.

His research focusses primarily on experimental second-order nonlinear optics. He has developed Hyper-Rayleigh Scattering as a unique experimental technique in molecular nonlinear optics, where it has provided a paradigm shift away from the simple neutral and dipolar species towards alternative symmetries and multifunctional, often charged, species. This research is in strong international collaboration for the design and synthesis of such advanced materials, for the theoretical rationalisation of the obtained experimental results and for the applications, e.g. in multimodal cellular imaging. On the side, he is also elaborating on the nonlinear optical properties of fluorescent proteins and chromoproteins. More recently, he has started a research endeavour in colloidal photonic crystals, where he is exploiting the possibilities of bandgap engineering, offered by the convenient bottom-up approach. He has been an invited professor at the universities of Nantes and Bordeaux (France) and is an elected Fellow of SPIE, the international society for optics and photonics.