1. Optical Materials Engineering Laboratory Department of Mechanical and Process Engineering ETH Zurich ETH Zurich Zurich 8092 Switzerland
2. I. Physikalisches Institut (1A) RWTH Aachen University Aachen 52056 Germany
3. Heidelberg Instruments Nano/SwissLitho Technoparkstrasse 1 Zurich 8005 Switzerland
4. Leibniz Institute for Interactive Materials Aachen 52076 Germany