1. Department of Physics, Faculty of Science, Yamagata University, Kojirakawa, Yamagata 990-8560
2. Physics Department, Graduate School of Science, Tohoku University, Sendai 980-8578
3. Organo-Optic Research Laboratory, 6-2-1 Seiwa-dai, Kita-ku, Kobe 651-1121
4. Center for Interdisciplinary Research, Tohoku University, Sendai 980-8578