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. Tokyo Metropolitan Industrial Technology Research Institute, 2-4-10 Aomi, Koto-ku, Tokyo 135-0064, Japan
3. Engineering Education Research Center, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8530, Japan
4. Photonics and Electronics Science and Engineering Center, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8520, Japan
5. Department of Electronic Science and Engineering, Kyoto University, Kyoto 615-8510, Japan