1. Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, People's Republic of China
2. State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China
3. MOE Key Laboratory of Materials Modification by Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024, People's Republic of China
4. CEA, IRFM, F-13108 Saint-Paul-lez-Durance, France