1. Soft Materials Department of Materials, ETH Zürich, Zürich CH-8093, Switzerland
2. Photonics Laboratory, ETH Zürich, Zürich CH-8093, Switzerland
3. Laboratory of Thermodynamics in Emerging Technologies Department of Mechanical and Process Engineering, ETH Zürich, Zürich CH-8092, Switzerland
4. Optical Materials Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, Zürich CH-8092, Switzerland
5. IBM Research, Zurich, Rüschlikon CH-8803, Switzerland
6. Department of Physics, Humboldt Universität zu Berlin, 12489Berlin, Germany