Professor                   

              Shinji Yamashita                      

                   Information Devices                    

                   E-mail: syama [AT] cntp.t.u-tokyo.ac.jp

                   Tel: 03-5452-5150 (Komaba),    03-5841-6659 (Hongo)                   

                   FAX: 03-5452-5155 (Komaba)

                   URL: https://researchmap.jp/sy2orc/

                   Research book

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Biography

                     1991.02  Research Associate, RCAST, The University of Tokyo

                     1994.08 Lecturer, RCAST, UTokyo

                     1995.04 Lecturer, School of Engineering, UTokyo

                     1996.04 Visiting Research Fellow, ORC, Southampton Univ., UK (-1998.4)

                     1999.04 Associate Professor, School of Frontier Sciences, UTokyo

                     2004.04 Associate Professor, School of Engineering, UTokyo

                     2009.07 Professor, School of Engineering, UTokyo

                     2013.04 Professor, RCAST, UTokyo

  Research Interests

We, the Yamashita-Lab., are mainly focusing on photonic devices, such as fiber devices and lasers, for telecom, sensing, and medical applications, and also on their system applications.

¹Fast and wide wavelength tunable fiber lasers and their OCT applications

We are working on the fiber lasers using Rare-earth-doped fibers or semiconductors for telecom and sensing applications. We are currently emphasizes on fast and wide wavelength tunable fiber lasers having very wide tuning range (>100nm) and a very fast tuning speed (Repetition rate > 100kHz). We are also trying to apply the lasers to the optical coherence tomography systems (OCT).

²Nanocarbon photonic devices and their applications

Nanocarbons, such as Carbon nanotubes (CNT) and graphene, have very interesting useful, not only mechanical and electrical, but also photonic properties. We are pursuing researches on nanocarbon photonics. We concentrate on the stable and high-energy short-pulse fiber lasers using the nanocarbons. Nanocarbons have very fast saturable absorption, which enables generation of short (~1ps) optical pulses through passive mode locking. We also demonstrated ultra-wideband supercontinuum (SC) generation using the laser as a seed source. We are trying to apply the SC source to the OCT system.

³Photonic devices for telecom and sensing applications

We are also working on photonic devices for telecom and sensing applications, such as wavelength converter and parametric amplifier using fiber nonlinearity, fiber lasers, and fiber filters.

Selected Publications

1. S. Yamashita, Y. Inoue, S. Maruyama, Y. Murakami, H. Yaguchi, M. Jablonski, and S. Y. Set, “Saturable absorbers incorporating carbon nanotubes directly synthesized onto substrates and fibers and their application to mode-locked fiber lasers,” Opt. Lett. 29, 1581-1583 (2004)
2. Yamashita S, Hotate K. Multiwavelength erbium-doped fibre laser using intracavity etalon and cooled by liquid nitrogen[J]. Electronics Letters, 1996, 32(14):1298-1299.
3. Amos Martinez, Kazuyuki Fuse, Bo Xu, and Shinji Yamashita, “Optical deposition of graphene and carbon nanotubes in a fiber ferrule for passive mode-locked lasing,” Opt. Express 18, 23054-23061 (2010)
4. Shinji Yamashita, “A Tutorial on Nonlinear Photonic Applications of Carbon Nanotube and Graphene,” J. Lightwave Technol. 30, 427-447 (2012)
5. Martinez A, Fuse K, Yamashita S. Mechanical exfoliation of graphene for the passive mode-locking of fiber lasers[J]. Applied Physics Letters, 2011, 99(12):3077.
6. Yamashita S. Widely tunable erbium-doped fiber ring laser covering both C-band and L-band[J]. Selected Topics in Quantum Electronics IEEE Journal of, 2001, 7(1):41-43.
7. Amos Martinez and Shinji Yamashita, “Multi-gigahertz repetition rate passively modelocked fiber lasers using carbon nanotubes,” Opt. Express 19, 6155-6163 (2011)
8. Ken Kashiwagi and Shinji Yamashita, “Deposition of carbon nanotubes around microfiber via evanascent light,” Opt. Express 17, 18364-18370 (2009)