1. Department of Physics, University of Otago, Dunedin, Otago 9016, New Zealand
2. MacDiarmid Institute for Advanced Materials and Nanotechnology, Dunedin, Otago 9016, New Zealand
3. Dodd-Walls Centre for Photonic and Quantum Technologies, Dunedin, Otago 9016, New Zealand
4. Department of Physics, University of Auckland, Auckland 1010, New Zealand
5. School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand
6. Department of Mechanical & Manufacturing Engineering, Miami University, Oxford, Ohio 45056, United States