1. Department of Physics, University of Ottawa, 25 Templeton Street, Ottawa, Ontario K1N 6N5, Canada
2. Max Planck Centre for Extreme and Quantum Photonics, Ottawa, Ontario K1N 6N5, Canada
3. Max Planck Institute for the Science of Light, 91058 Erlangen, Germany
4. Department of Physics, University of Erlangen-Nürnberg, 91058 Erlangen, Germany
5. National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
6. Interdisciplinary Center for Nanostructured Films, 91058 Erlangen, Germany