1. Gérard Mourou Center for Ultrafast Optical Science, University of Michigan, 2200 Bonisteel Boulevard, Ann Arbor, Michigan 48109, USA
2. Lawrence Livermore National Laboratory, Livermore, California 94550, USA
3. Blackett Laboratory, Imperial College, London SW7 2AZ, United Kingdom
4. Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543, USA
5. Laboratory for Laser Energetics, 250 East River Road, Rochester, New York 14623, USA