1. Cavendish Laboratory University of Cambridge Cambridge CB3 0HE UK
2. Micro and Nanophotonic Materials Group Research Institute for Materials Science and Engineering University of Mons Place du Parc 20 7000 Mons Belgium
3. School of Electrical and Electronic Engineering Nanyang Technological University 50 Nanyang Ave Singapore 639798 Singapore
4. Singapore Institute of Manufacturing Technology 2 Fusionopolis Way, Innovis Singapore 138634 Singapore
5. Paul Scherrer Institute 5232 Villigen Switzerland
6. Department of Physics Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
7. Institute of Applied Physics University of Bern Bern 3012 Switzerland
8. Department of Electrical Engineering Technion – Israel Institute of Technology Haifa 32000 Israel