1. Imec, Kapeldreef 75, B-3001 Leuven, Belgium
2. Department of Electrical Engineering
(ESAT), Katholieke Universiteit Leuven,
Kasteelpark Arenberg 10, B-3001 Leuven, Belgium
3. Photonics Research Group (INTEC), Ghent University-Imec, Sint-Pietersnieuwstraat 41,
B-9000 Gent, Belgium
4. Micro-
and Nanophotonic Materials Group, Faculty of Science, University of Mons, Avenue Maistriau 19, B-7000 Mons,
Belgium