1. Department of Physics and Astronomy, University of Canterbury, PB 4800, Christchurch 8410, New Zealand
2. The Dodd-Walls Centre for Photonic and Quantum Technologies and Department of Physics and Astronomy, University of Canterbury, PB 4800, Christchurch 8140, New Zealand
3. MacDiarmid Institute for Advanced Materials and Nanotechnology and Department of Physics and Astronomy, University of Canterbury, PB 4800, Christchurch 8140, New Zealand
4. Radboud University Nijmegen, Institute for Molecules and Materials, FELIX Facility, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
5. Debye Institute for NanoMaterials Science, University of Utrecht, P.O. Box 80000, TA 3508 Utrecht, The Netherlands