Speaker: Prof. Masayoshi Tonouchi
Affiliation: Institute of Laser Engineering Osaka University, Suita, Japan
Abstract: One can observe terahertz (THz) radiation from various kinds of materials, when excited with a femtosecond laser, owing to ultrafast current modulation. THz waves reflect various kinds of properties such as local electric field, particularly ultrafast transient phenomena, in their waveforms. The observation of the THz waveforms enables us to explore ultrafast nature of electronic materials and devices as a THz emission spectroscopy. When one excites the THz emission from a certain substance with the femtosecond optical pulses and visualizes the emission image by scanning the laser beam on it, the resolution of the image is limited by the laser beam diameter rather than THz wavelength; thus, construction of a laser-THz emission microscope (LTEM) would provide a new tool for material/device science and industrial applications. We proposed and have been developing the LTEM since 1997. In this talk, we will report the basics of LTEM, dynamic pump-and-probe LTEM (DTEM), near field LTEM, and some examples focusing on the evaluation of solar cells including deep inside imaging of carrier dynamics in a TUNDEM cell, and GaN wafers. The molecular desorption study from atomic layer materials and THz microfluidic devices for high-sensitivity biochips are also other interesting applications that will be discussed.
Biography: Masayoshi Tonouchi received the B.S. and M.S. and Dr. E. degrees form Osaka University, Japan, in 1983, 1985 and 1988, respectively. From 1988 to 1989, he worked at the Faculty of Engineering Science of the same university. From 1989 to 1994, he joined the Faculty of Computer Science and System Engineering, Kyushu Institute of Technology, Japan. In 1994, he moved to Kansai Advanced Research Center, Communications Research Laboratory, Japan. From 1996 to 2000, he was an associate professor at the Research Center for Superconducting Materials and Electronics, Osaka University. Currently, he is a professor in Institute of Laser Engineering, Osaka University and a concurrent professor of Nanjing University. His current research interests include ultrafast optical and terahertz science of strongly correlated electron systems and nanomaterials, and development-and-applications of terahertz systems such as the laser terahertz emission microscope, compact THz time-domain spectroscopy systems, and others. He is a member of the Optical Society of America, Materials Research Society, the Japan Society of Applied Physics, the Physical Society of Japan, and the Institute of Electronics, Information and Communication Engineers. He has been an associate editor for Journal of Applied Physics, AIP since January 1st, 2015. Prof. Tonouchi has also chaired many international conferences such as OTST 2013.
Date(s) - May 11, 2018
4:00 pm - 5:00 pm
E-IV Tesla Room #53-125
420 Westwood Plaza - 5th Flr., Los Angeles CA 90095