1. Department of Applied Physics, National Defense Academy, 1-10-20 Hashirimizu, Yokosuka 239-8686, Japan
2. Graduate School of Science and Engineering, Yamaguchi University, Yamaguchi 753-8512, Japan
3. Department of Organic and Polymer Materials Chemistry, Tokyo University of Agriculture and Technology, Koganei 184-8588, Japan
4. Department of Materials Science and Engineering, University of Tokyo, Tokyo 113-8656, Japan