1. Institute of Microstructure Technology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany
2. Light Technology Institute, Karlsruhe Institute of Technology (KIT), Engesserstrasse 13, Karlsruhe 76131, Germany
3. Singulus Technologies AG, Hanauer Landstrasse 103, Kahl/Main D-63796, Germany