1. Department of Applied Physics, Aalto University, P.O. Box 13500, Aalto FI-00076, Finland
2. Department of Physics of Information in Matter and Center for Nanophotonics, NWO-I Institute AMOLF, Science Park 104, Amsterdam 1098 XG, The Netherlands
3. Advanced Research Center for Nanolithography (ARCNL), Science Park 106, Amsterdam 1098 XG, The Netherlands
4. Department of Sustainable Energy Materials and Center for Nanophotonics, NWO-I Institute AMOLF, Science Park 104, Amsterdam 1098 XG, The Netherlands
5. Optoelectronic Materials Section, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, Delft 2629 HZ, The Netherlands
6. Institute of Physics, University of Amsterdam, Amsterdam 1098 XH, The Netherlands