1. Department of Applied Physics, School of Advanced Engineering and Department of Electrical Engineering and Electronics, Graduate School of Engineering, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo 192-0015, Japan
2. National Institute of Information and Communications Technology, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo 184-8795, Japan
3. Novel Crystal Technology, Inc., Sayama, Saitama 350-1328, Japan
4. Tamura Corporation, 2-3-1 Hirosedai, Sayama, Saitama 350-1328, Japan