S. Höfer, A. Liem, J. Limpert, H. Zellmer, and A. Tünnermann
Institute of Applied Physics, Friedrich-Schiller-University Jena, Max-Wien-Platz 1, D-07743 Jena, Germany
S. Unger, S. Jetschke, and H.-R. Müller
Institute for Physical High Technology Jena, Winzerlaer Strasse 10, D-07745 Jena, Germany
I. Freitag
Innolight GmbH, Vahrenwalder Strasse 7, D-30165 Hannover, Germany