1. Contribution from the Department of Physics, Yonsei University, Seoul 120-742, Korea, Electronic Device Group, Korea Research Institute of Standards and Science, Taejon 305-600, Korea, School of Chemistry, Seoul National University, Seoul 151-742, Korea, Center for Ultrafast Optical Characteristics Control and Department of Chemistry, Yonsei University, Seoul 120-749, Korea, and Department of Chemistry, Kyoto University, Kyoto 606-8502, Japan