1. Faculty of Science and Technology, Keio University, Yokohama, Kanagawa 223-8522, Japan, JST ERATO, Koike Photonics Polymer Project, K2 TOWN CAMPUS, 144-8 Ogura, Saiwai-ku, Kawasaki, Kanagawa, 212-0054, Japan
2. Department of Chemistry and Polymer Research Institute, Polytechnic University, 6-Metrotech Center, Brooklyn, New York 11201