|Affiliation||Department of Electrical and Electronic Information Engineering|
|Fields of Research||Optical near-field, Diamond, Quantum sensor, Artificial photosynthesis|
|Degree||Doctor of Engineering|
|Academic Societies||Japan Society of Applied Physics, IEEE, The Laser Society of Japan|
Please append "tut.jp" to the end of the address above.
|Laboratory website URL||https://lux.ee.tut.ac.jp/|
|Researcher information URL（researchmap）||Researcher information|
The size of the devices have been reduced to nano-meter scale to meet the requirement using "nanotechnology". Optical near-field (ONF) has made it possible to reduce the size of photonic devices to the sub-wavelength scale or smaller. For further development of the photonics we are interested in the use of the unique properties of ONF, which are originated from the non-uniformity of the electric and/or magnetic field in nano-scale. Using the ONF, we realized unconventional photo-reaction, resulting the nano-scale device and sub-nanometer scale fabrication process.
We developed near-field etching technique which can realize ultra-flat surface. This technique can realize drastic improvement of the performance of opto-electronic device, including magnetic-filed sensor with high sensitivity using diamond quantum sensors
Selected publications and works
 Akihiro Kuwahata, Takahiro Kitaizumi, Kota Saichi, Takumi Sato, Ryuji Igarashi, Takeshi Ohshima, Yuta Masuyama, Takayuki Iwasaki, Mutsuko Hatano, Fedor Jelezko, Moriaki Kusakabe, Takashi Yatsui, and Masaki Sekino, “Magnetometer with nitrogen-vacancy center in a bulk diamond for detecting magnetic nanoparticles in biomedical applications,” Scientific Reports, Volume 10, February 2020, 2483 (9 pages)
 Felix Brandenburg, Ryosuke Nagumo, Kota Saichi, Kosuke Tahara, Takayuki Iwasaki, Mutsuko Hatano, Fedor Jelezko, Ryuji Igarashi, and Takashi Yatsui, “Improving the electron spin properties of nitrogen-vacancy centres in nanodiamonds by near-field etching,” Scientific Reports, Vol. 8, October 2018, 15847 (8 pages)
 Takashi Yatsui, Maiku Yamaguchi and Katsuyuki Nobusada, “Nano-scale chemical reactions based on non-uniform optical near-fields and their applications,” Progress in Quantum Electronics, September 2017, Vol. 55, pp. 166-194. [review article].
 Takashi Yatsui, Toshiki Tsuboi, Maiku Yamaguchi, Katsuyuki Nobusada, Satoshi Tojo, Fabrice Stehlin, Olivier Soppera, and Daniel Bloch, “Optically controlled magnetic-field etching on the nano-scale,” Light: Science & Applications, Volume 5, March 2016; e16054 (7 pages)
 Manfred Mascheck, Stephen Schmidt, Martin Silies, Takashi Yatsui, Kokoro Kitamura, Motoichi Ohtsu, David Leipold, Erich Runge, and Christoph Lienau, “Observing the localization of light in space and time by ultrafast second-harmonic microscopy,” Nature Photonics, Vol. 6, No. 5, May 2012, pp.283-292.
We have developed a method to achieve the red-shift of the absorption spectra of the materials using the optical near-field (ONF) effect. This can help reduce the photon energies required for completing chemical reactions in a wide range of applications such as CO2 reduction, water splitting, etc.
Selected publications and works
 Naoya Tate and Takashi Yatsui, “Visible light-induced thymine dimerisation based on large localised field gradient by non-uniform optical near-field,” Scientific Reports, Volume 9, December 2019, 18383 (6 pages)
 Takashi Yatsui, Yusuke Nakahira, Yuki Nakamura, Tatsuki Morimoto, Yuma Kato, Muneaki Yamamoto, Tomoko Yoshida, Kenji Iida, and Katsuyuki Nobusada, “Realization of red shift of absorption spectra using optical near-field effect,” Nanotechnology, Vol. 30, No. 34, June 2019, 34LT02 (9 pages)
 Takashi Yatsui, Tsubasa Imoto, Takahiro Mochizuki, Kokoro Kitamura, and Tadashi Kawazoe, “Dressed-photon–phonon (DPP)-assisted visible- and infrared-light water splitting,” Scientific Reports, Vol. 4, April 2014, 4561 (5 pages)
 N. Tanjeem, T. Kawazoe, and T. Yatsui, “CO2 phonon mode renormalization using phonon-assisted energy up-conversion,” Scientific Reports, Vol. 3, Article number: 3341, November 2013 (8 pages)
Title of class
Quantum Mechanics 1 (B12610110), Electronic Materials 1 (M22621060)
Others (Awards, Committees, Board members)
 Optical Engineering Award (Takawano Award) from JSAP, 2019
 APEX/JJAP Editorial Contribution Award, 2016
 48th The Ichimura Prize in Science from The New Technology Development Foundation, 2016
 Fujisankei Business i Award from Fujisankei Business i, 2013
 Erlangen Innovation Award Optical Technologies 2012.
 Kondo Prize 2012 from Osaka University, 2012.
 German Innovation Award, Gottfried Wagner Prize 2010 from Deutsches Wissenschafts- und Innovationshaus & Deutsche Industrie- und Handelskammer in Japan, 2011.
 Tejima Doctoral Dissertation Award from Tejima Foundation, 2001.
 The excellent research presentation award from the Japan Society of Applied Physics, 2000.
 1st prize in Paper Contest from IEEE Student Branch at Tokyo Institute of Technology, 1998.
SERVICES IN ACADEMIC SOCIETIES
1. Editor on APEX & JJAP, 2014-present
2. Editor, Progress in Nanophotonics (Springer Series in Nano-optics and Nanophotonics), 2014 – present
3. Membership Development Committee Chair, IEEE Tokyo Branch, 2017-2018
SERVICES IN INTERNATIONAL CONFERENCES
1. International Advisory Committee of Asia-Pacific Conference on Near-Field Optics, 2015 – present
2. APNFO-10 Program Committee Chair, The 10th Asia-Pacific Conference on Near-Field Optics (APNFO-10), 2015
3. APNFO-8 Co-Chair, The 8th Asia-Pacific Conference on Near-Field Optics (APNFO-8), 2011