1. Department of Physics, Northeastern University, Boston, Massachusetts 02115, United States
2. Materials Synthesis and Integrated Devices, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
3. Department of Physics, Southern Illinois University Carbondale, Carbondale, Illinois 62901, United States
4. Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
5. Department of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts 02115, United States
6. George J. Kostas Research Institute for Homeland Security, Northeastern University, Burlington, Massachusetts 01803, United States