1. Fraunhofer-Institut für Angewandte Festkörperphysik (IAF), Tullastrasse 72, 79108 Freiburg, Germany.
2. National Institutes for Quantum Science and Technology (QST), 1233 Watanuki, Takasaki, Gunma 370-1292, Japan.
3. College of Staten Island, CUNY, 2800 Victory Blvd., Staten Island, NY 10312, USA.
4. Gemological Institute of America, 50 W 47th St. #800, New York, NY 10036, USA.
5. School of Science, RMIT University, Melbourne, VIC 3001, Australia.
6. ARC Centre of Excellence for Nanoscale BioPhotonics, School of Science, RMIT University, Melbourne, VIC 3001, Australia.