1. Institute of Analytical and Bioanalytical Chemistry, Ulm University 1 , Albert-Einstein-Allee 11, D-89081 Ulm, Germany
2. Nanoplus Advanced Photonics Gerbrunn GmbH 2 , Oberer Kirschberg 4, 97218 Gerbrunn, Germany
3. Laser Components Germany GmbH 3 , Werner-von-Siemens-Strasse 15, D-82140 Olching, Germany
4. Hahn-Schickard 4 , Sedanstrasse 14, D-89077 Ulm, Germany