Institution: | a Light Technology Institute, Universität Karlsruhe (TH), Engesser Str. 13, D-76131 Karlsruhe, Germany b Department of Applied Physics and Photonics, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium c Faculty of Engineering, University of Applied Sciences Trier, Postfach 1826, D-54208 Trier, Germany |