1. Faculty of Engineering, Brussels Photonics team B-PHOT, TONA-FirW; Vrije Universiteit Brussel; Pleinlaan 2 1050 Brussels Belgium
2. Faculty of Engineering, Research Group Electrochemical and Surface Engineering, Department of Materials and Chemistry, SURF-FirW; Vrije Universiteit Brussel; Pleinlaan 2 B-1050 Brussels Belgium
3. Department of Art Sciences and Archaeology; Vrije Universiteit Brussel; Pleinlaan 2 1050 Brussels Belgium