Koshihara Okimoto Lab.

Shin-ya Koshihara
Shin-ya Koshihara

Present Affiliation:
Professor of Tokyo Institute of Technology
Graduate School of Science and Engineering,
Department of Chemistry and Materials Science,
2-12-1-H61, Oh-okayama, Meguro-ku, Tokyo 152-8551, Japan
Tel/Fax +81-3-5734-2449 e-mail skoshi@cms.titech.ac.jp

University of Tokyo, Physics B.S. 1983
University of Tokyo, Physics, M.S. 1985
Ph.D. University of Tokyo, 1991

Professional Experience
Academic Carrier
1986-1991: Assistant Professor of the University of Tokyo, Department of Physics
1991-1993: Researcher of Photo-dynamics Research Center (in Sendai), RIKEN
1993-1998: Associate Professor of Tokyo Institute of Technology, Department of Applied Physics
1998-2000: Associate Professor of Tokyo Institute of Technology, Department of Physics
2000-Prsent: Professor of Tokyo Institute of Technology, Department of Chemistry and Materials Science

2004-2009: Visiting Professor of KEK
2005-2009: Professor of Frontier Research Center, Tokyo Institute of Technology

1993-1997: Visiting Researcher of RIKEN, Photo-dynamics Research Center
1998-2003: Leader of the Project in Kanagawa Academy of Science and Technology (KAST)
2003-2009: Director of ERATO Project of JST (Japan Science and Technology Agency)
2009-Present: Leader of CREST Project of JST

2002-2007, 2011-Present: Advisor of PRESTO Project of JST
2008-Present: Scientific Advisory Board member of the KEK ERL (Energy Recovery Linac) Project Office
2005-Present: Scientific Committee member of the Ministry of Education, Science, Culture and Sports, Japan, for the Application of Free Electron Laser in Hard X-ray region
2011-Present Member of the Science Council of Japan
2012-Present Organizing Committee Member of KEK-Photon Factory (PF) User Association (PF-UA)
2012-2013 Division (Optical Properties of Materials) sub-head of The Physical Society of Japan
2013-2014 Division head of The Physical Society of Japan Chairman of the 63th Yamada Conference gPhoto-induced Cooperative Phenomenah

Publication List of Shinya KOSHIHARA(12th February 2013)

The discovery of the laser in the 1960s had a tremendous effect on both basic research and new technology. With its very narrow line width, coherence and power, lasers revolutionized the field of atomic and molecular spectroscopy, which resulted in a better understanding of atoms, molecules and materials. In subsequent years, the wavelength regions of lasers greatly expanded to cover from infrared to ultraviolet. In addition, faster pulsed lasers with very short pulses were produced that found many applications from the 1980s, especially in stimulating chemical reactions and analyzing the results. This gpump and probeh methodology gave research scientists a much better tool for controlling and analyzing the details of chemical of reactions. Scientists waited many years for a pulsed laser fast enough to probe some of the intriguing aspects of materials. 25 years ago, we succeeded in a novel experiment with a nanosecond laser involving photoinduced transitions of a material. The fast laser was absolutely necessary to do this experiment. We are now particularly interested in phase switching in various materials. This involves a sudden photoinduced transition, phase change, over a macroscopic region, as compared to localized changes in past work. For instance, all molecules of a material would change in a domino-like effect from trans to cis together. Already we have succeeded to stimulate a variety of cooperative phenomena by photoexcitation: photoinduced magnetism, moleacular ferroelectricity, metal-insulator transitions accompanied with structural dynamics. For example, in the case of involves changing a .1 mm donor-acceptor type chargetransfer organic crystal into a more stable ionic crystal, thus unifying the two possibilities based on the long-range cooperative Coulomb interaction. Interestingly, there is also a color change from yellow to red along with the phase shift, allowing the phase transition to be probed very sensitively. This very fundamental effect could be important for optical memory based on color change, or optical switching for signal processing. Cooperative change in the charge transfer is also like that which takes place in photosynthesis and other biological phenomena. We are presently using a laser to observe phase transitions between two phases with a switching speed of less than about 100 femtoseconds. Since phenomena in materials are strongly combined with the phonon vibration of the crystal, considered to be a basic starting point, or a fundamental process for the phase transition, the basic process of a photoinduced phase change reaches within a speed of one vibration, or the vibration frequency. Thus, we are developing the facilities for probing ultrafast structural changes utilizing laser-electron-synchrotron combined technologies based on wide (international) collaborations..