1. Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
2. Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, California 91125, United States
3. Institute for Laser Science, University of Electro-Communications, Tokyo 182-8585, Japan
4. Atomic, Molecular and Optical Physics Laboratory, RIKEN, Saitama 351-0198, Japan
5. Department of Physics, University of Toyama, Toyama 930-8555, Japan
6. Molecular Photoscience Research Center, Kobe University, Kobe 657-8501, Japan