1. Department of Chemistry, University of Washington, Seattle, WA 98195, USA
2. Nonlinear Materials Corporation, Seattle, WA 98109, USA
3. Polariton Technologies AG, 8803 Rüschlikon, Switzerland
4. Institute of Electromagnetic Fields, ETH Zurich, Gloriastrasse 35, Zurich 8092, Switzerland
5. Department of Chemistry, University of Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium