Shinji Yamashita

Professor Shinji Yamashita

Research Center for Advanced Science and Technology, University of Tokyo

Carbon Nanotube and Graphene Photonics
We review the optical properties of carbon nanotubes (CNTs) and graphene, and describe how those properties have been used for the implementation of various nonlinear fiber optic applications. Early studies on the optical properties of CNTs revealed that these materials exhibit high third order susceptibility and a broadband saturable absorption with a sub-picosecond response time. Recent discovery of similar nonlinear optical properties in graphene attracts much attention in this field.
Such ultrafast, highly nonlinear optical response means that they can be employed for noise suppression and for the mode-locking of fiber lasers, and in addition, their high third order nonlinearity holds great promise for the implementation of various other nonlinear fiber optic devices such as wavelength converters based on four wave mixing. In this lecture, we will discuss the various methods that have been considered thus far for the integration of CNTs and graphene in optical systems and highlight the advantages and limitations of using the saturable absorption of CNTs and graphene for the passive mode-locking of fiber lasers, and the current status of CNT and graphene saturable absorbers in the state of art fiber laser technologies.

Shinji Yamashita was born in Osaka, Japan, on August 14, 1965. He received the B.E., the M.E. and Dr. Eng. degrees in Electronic Engineering from the University of Tokyo, Tokyo, Japan in 1988, 1990, and 1993, respectively. He was appointed as a Research Associate in 1991, a Lecturer in 1994, an Associate Professor in 1998, and a Professor in 2009, at the University of Tokyo. At present, He is a Professor at the Research Center for Advanced Science and Technology (RCAST), the University of Tokyo. From 1996 to 1998, he stayed at Optoelectronics Research Center (ORC), University of Southampton, UK, as a visiting research fellow. He has been engaged in research of coherent optical fiber communications, optical fiber amplifiers, fiber nonlinearities and fiber lasers. His current interest is in fiber lasers and nonlinear devices for optical fiber communications and sensors. He has published and presented over 250 refereed papers in the field. He is a member of the Institute of Electrical and Electronics Engineers (IEEE), Optical Society of America (OSA), the Institute of Electronics, Information, and Communication Engineers of Japan (IEICE), and the Japan Society of Applied Physics (JSAP).