**Acknowledgements**

Parts of the work presented in this chapter was carried out using laser facilities in the spectroscopy section of the Institute for Solid State Physics, the University of Tokyo, as a part of joint research. This work was financially supported in part by a Grant-in-Aid for Scientific Research on Innovative Areas, Frontier Science of Interactions between Plasmas and Nanointerfaces (No. 21110002), from the Ministry of Education, Culture, Sports, Science and Technology of Japan, and a Grant-in-Aid for JSPS Fellows (No. 12J03125) from the Japan Society for the Promotion of Science. The authors would like to thank previous members of the Terashima Laboratory for their contribution and experimental work to parts of the results presented: Mr. Sho Nakahara, Mr. Shoehei Himeno, and Mr. Yoshihiko Takizawa. Moreover, we would like to thank Prof. Emer. Tohru Suemoto (Institute of Solid State Physics, The University of Tokyo), and Prof. Motoyoshi Baba (Saitama Medical University), for their collaboration.
