1. Nanophotonics Laboratory, Photonics Center, Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia
2. Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Celestijnenlaan 200 D, Box 2425, B-3001 Leuven, Belgium
3. Institute of Applied Sciences and Intelligent Systems, Unit of Naples, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
4. Department of Physics & Namur Institute of Structured Matter (NISM) and Namur Institute for Complex Systems (naXys), University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium
5. Micro- and Nano-Photonics Materials Group, University of Mons, Avenue Maistriau 19, B-7000 Mons, Belgium