1. Nonlinear Physics Centre and Centre for Ultrahigh-bandwidth Devices for Optical Systems, Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 2601, Australia.
2. Institute of Applied Physics, Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, D-07745 Jena, Germany.
3. Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 2601, Australia.
4. Leibniz Institute of Photonic Technology, D-07745 Jena, Germany.
5. Technische Universität Darmstadt, Merckstraße 25, Darmstadt, Germany.