Kenta Takata, Ph.D.
NTT Nanophotonics Center
Photonic Nanostructure Research Group,
Advanced Applied Physical Science Laboratory,
NTT Basic Research Laboratories
Make it simple, elegant and practical!
Updates
- Our paper was been published in Physical Review A (2025.3.17)!
- Our collaborative paper has been published in Optics Letters (2025.3.10)!
- Visited NTT Research PHI Labs. Thank all who kindly took time for me (2025.1.29)!
- Had an invited talk at SPIE Photonics West (2025.1.28).
- Submitted a manuscript (2024.10.24).
- I will have a short parental leave (2024.9.1).
- Had a presentation at CLEO 2024 (2024.5.10).
- Talked at a JSAP spring meeting (2024.3.22).
- Talked at a JSAP autumn meeting (2023.9.21).
- I have served out as the chief of NTT Union Atsugi R&D Division Office (2023.8.30).
- Prof. Adam Mock completed his 1-year visit at NTT and got back to Michigan. Hope to see him soon (2023.8.3)!
- Submitted a preprint (2023.5.7).
- Poster presentation at PECS-XIII (2023.3.31).
- Our paper has been published in Optics Express (2023.3.24).
- Talked at a JSAP spring meeting (2023.3.16).
- Visited NTT Research PHI Lab. Thank the people there for a fruitful discussion and lab tour (2023.2.3)!
- Had a presentation at SPIE Photonics West (2023.1.31).
- Submitted a preprint (2023.1.6).
- Talked at a JSAP autumn meeting (2022.9.20).
- Had a seminar by Prof. Schomerus. Thank him for a fruitful discussion! (2022.9.2).
- Talked at CLEO-PR about non-Hermitian nanophotonics. (2022.8.3).
- Some Japanese review articles have been published (2022.7.7).
- I'm working as a topic committee of IEEE Photonics Conference (2022.6.1).
- Talked in ICNN2022 about non-Hermitian nanophotonics (2022.4.18).
- Talked in the symposium of the JPS annual meeting (2022.3.19).
- Our paper was published in Physical Review A (2022.1.25).
- Had a presentation at FiO+LS 2021 (2021.11.2).
- Submitted a preprint (2021.7.19).
- Published a paper in Scientific Reports (2021.4.21).
- Talked at a JSAP spring meeting (2021.3.17).
- I was selected as an APS Outstanding Referee (2021.2.25).
- Our paper has been published in Optica (2021.2.3).
- Talked at a JSAP autumn meeting (2020.9.10).
- Prof. Notomi gave an invited talk about our studies at the
SPIE Nanoscience+Engineering (2020.8.20).
- Submitted a preprint (2020.7.6).
- We are working home to fight against the pandemic of
coronavirus (2020.4.10).
- Our work has been published in Communications Physics
(2020.3.9).
- Our collaborative review paper has been published
in Nanophotonics (2020.1.30).
- Nathan completed his internship placement.
Hope to see him again (2019.12.20)!
- Had a talk in Frontiers in Optics, at Washington D.C. (2019.9.17).
- Mr. Nathan Roberts joined as my first intern (2019.7.1).
- Invited Dr. Ryan Hamerly as a guest presenter.
Hope to see him soon (2019.6.24).
- Visited Mr. Kohei Kawabata at University of Tokyo.
Thank him for fruitful discussion (2019.6.18).
- My e-mail address has been changed.
Contacts to the old address will still be forwarded (2019.6.7).
- Talked at Optics and Laser 2019, at San Francisco (2019.6.3).
- Gave a talk at a JSAP spring meeting (2019.3.11).
- Presented a poster talk at a CREST meeting (2018.12.12).
- Launched a press release about the PRL paper (2018.12.5).
- Published a paper in Physical Review Letters (2018.11.20).
- Talked at a JSAP fall meeting (2018.9.19).
- Talked at PIERS 2018 (2018.8.4).
- Published an introductory article for non-experts (2018.7.11).
- Published a Japanese review paper (2018.5.17).
- Gave a presentation at CLEO 2018 (2018.5.14).
- Gave a poster talk at a CREST meeting (2017.12.21).
- Served as a tutor of NTT-BRL School.
Thank all the students for visiting us! (2017.11.17).
- Submitted a preprint (2017.10.25).
- Gave two talks in a JSAP fall meeting (2017.9.8).
- Awarded by the Japanese Society of Applied Physics (2017.9.5).
- Gave a talk in ICO-24 (2017.8.24).
- Published a paper in Physical Review Applied (2017.5.26).
- A presentation was featured in Nature Photonics (2017.4.28).
- Published a paper in APL Photonics (2017.3.24).
- Gave a talk in a JSAP spring meeting (2017.3.15).
Research fields
Nanophotonics, Nonlinear Optics, Quantum Optics, Semiconductor Physics
Research projects
My interest is to explore the intersection of future applications of advanced photonic crystal devices and novel concepts of basic photonic research, covering PT-symmetric optics (photonic exceptional points), topological photonics and coherent optical information processing circuits.
Please see this technology introduction about our work on the observation of an exceptional point and a press release for our finding on gain- and loss-based non-Hermitian topological photonics.
Publications
International journals
- Exceptional-point restoration and fast-light edge states in photonic crystal waveguides with glide and time reversal symmetries,
T. Uemura, T. Yoda, Y. Moritake, S. Otsuka, K. Takata and M. Notomi,
Physical Review A 111, 033513 (2025).
*Preprint: arXiv:2410.18346 (2024).
- Slow light waveguides based on bound states in the continuum,
Y. Tanimura, Y. Ishii, K. Takata, T. Uemura, M. Notomi, S. Iwamoto and Y. Ota ,
Optics Letters 50 (6), 2013-2016 (2025).
- Optical non-Hermitian skin effect in two-dimensional uniform media,
T. Yoda, Y. Moritake, K. Takata, K. Yokomizo, S. Murakami and M. Notomi,
Preprint in arXiv, arXiv:2303.05185 (2023).
- Improved design and experimental demonstration of ultrahigh-Q C6-symmetric H1 hexapole photonic crystal nanocavities,
K. Takata, E. Kuramochi, A. Shinya and M. Notomi,
Optics Express 31 (7), 11864-11884 (2023).
*Preprint: arXiv:2301.02376 (2023). - Imaginary couplings in non-Hermitian coupled-mode theory: Effects on exceptional points of optical resonators,
K. Takata, N. Roberts, A. Shinya and M. Notomi,
Physical Review A 105, 013523 (2022).
*Preprint: arXiv:2107.08604 (2021). - Emulating the local Kuramoto model with an injection-locked photonic crystal laser array,
N. Takemura, K. Takata, M. Takiguchi and M. Notomi,
Scientific Reports 11, 8587 (2021).
*Preprint: arXiv:2010.16236 (2020). - Observing exceptional-point degeneracy of radiation with electrically pumped photonic crystal coupled-nanocavity lasers,
K. Takata, K. Nozaki, E. Kuramochi, S. Matsuo, K. Takeda, T. Fujii, S. Kita, A. Shinya and M. Notomi,
Optica 8 (2), 184-192 (2021).
*Preprint: arXiv:2007.02638 (2020). - Ultrashort low-loss Ψ gates for linear optical logic on Si photonics platform,
S. Kita, K. Nozaki, K. Takata, A. Shinya, and M. Notomi,
Communications Physics 3, 33 (2020).
Issued a NTT press release (in Japanese). - Active topological photonics,
Y. Ota, K. Takata, T. Ozawa, A. Amo, Z. Jia, B. Kante, M. Notomi, Y. Arakawa and S. Iwamoto,
Nanophotonics 9 (3), 547-567 (2020).
*Preprint: arXiv:1912.05126 (2019).
I'm in charge of the section about non-Hermitian topological physics and photonics. - Photonic Topological Insulating Phase Induced Solely by Gain and Loss,
K. Takata and M. Notomi,
Physical Review Letters 121 (21), 213902 (2018). [Editors' Suggestion]
Issued a NTT press release (in English and Japanese).
Featured in Nature Communications 9, 2674 (2018).
*Accepted manuscript by CHORUS.
*Preprint: arXiv:1710.09169 (2017). - PT-Symmetric Coupled-Resonator Waveguide Based on Buried Heterostructure Nanocavities,
K. Takata and M. Notomi,
Physical Review Applied 7 (5), 054023 (2017). [Editors' Suggestion]
*Accepted manuscript by CHORUS.
- Coherent control of high efficiency metasurface beam deflectors with a back partial reflector,
S. Kita, K. Takata, M. Ono, K. Nozaki, E. Kuramochi, K. Takeda and M. Notomi,
APL Photonics 2 (4), 046104 (2017). [Editor's Pick]
Introductory article, for non-experts
- Observation of Exceptional Point Degeneracy with Current-injected Photonic Crystal Lasers,
K. Takata, K. Nozaki, E. Kuramochi, S. Matsuo, K. Takeda, T. Fujii, S. Kita, A. Shinya and M. Notomi,
NTT Technical Review, 20 (8), 35 (2022). - Control of Light with Exceptional Points in Coupled Photonic Crystal Lasers,
K. Takata and M. Notomi,
NTT Technical Review, 16 (7), 26 (2018).
Domestic journal, in Japanese
- Optics Researches of Japan in 2021: Non-Hermitian Nanophotonics,
K. Takata et al.,
Japanese Journal of Optics, 51 (6), 270 (2022). - Observation of Exceptional Point Degeneracy with Current-injected Photonic Crystal Lasers,
K. Takata, K. Nozaki, E. Kuramochi, S. Matsuo, K. Takeda, T. Fujii, S. Kita, A. Shinya and M. Notomi,
NTT Technical Journal, 34 (6), 20 (2022). - Non-Hermitian Optical Periodic Systems and Topological Photonics,
M. Notomi and K. Takata,
Japanese Journal of Optics, 49 (11), 454-460 (2020). - Control of light with exceptional points in coupled photonic crystal lasers,
K. Takata and M. Notomi,
NTT Technical Journal, 30 (5), 23 (2018).
Presentations, as talker
International conferences
- Advancing photonic crystal devices by non-Hermitian degeneracies,
Kenta Takata, Adam Mock, Masaya Notomi and Takahiro Uemura,
SPIE Photonics West 2025, 13375-25, San Francisco, US, January 2025 [Invited]. - Designing Higher-Order Exceptional Points of Photonic Resonators by the Nilpotent Condition,
Kenta Takata, Adam Mock, Masaya Notomi and Akihiko Shinya,
Conference on Lasers and Electro-Optics (CLEO 2024), FF3M.6, Charlotte, US, May 2024. - Improving quality factors of hexapole point-defect photonic crystal nanocavities,
Kenta Takata, Eiichi Kuramochi, Akihiko Shinya and Masaya Notomi,
The 13th International Symposium on Photonic and Electromagnetic Crystal Structures (PECS-XIII), P-29, Tokyo, March 2023. - H1 hexapole photonic crystal nanocavities with theoretical and measured quality factors exceeding 108 and 106,
Kenta Takata, Eiichi Kuramochi, Akihiko Shinya and Masaya Notomi,
SPIE Photonics West 2023, 12431-14, San Francisco, January 2023. - Non-Hermitian nanophotonics with photonic crystal cavities,
Kenta Takata, Kengo Nozaki, Eiichi Kuramochi, Shinji Matsuo, Koji Takeda, Takuro Fujii, Shota Kita, Nathan Roberts, Akihiko Shinya and Masaya Notomi,
Conference on Lasers and Electro-Optics Pacific Rim (CLEO-PR2022), CTuP8B-04, Sapporo, August 2022 [Invited]. - Non-Hermitian physics in coupled photonic crystal nanocavities,
Kenta Takata, Kengo Nozaki, Eiichi Kuramochi, Shinji Matsuo, Koji Takeda, Takuro Fujii, Shota Kita, Akihiko Shinya and Masaya Notomi,
International Conference on Nano-photonics and Nano-optoelectronics (ICNN 2022), ICNN1-03, Yokohama, April 2022 [Invited]. - Non-Hermitian Temporal Coupled-Mode Theory: Effects of Imaginary Couplings on Exceptional Points,
Kenta Takata, Nathan Roberts, Akihiko Shinya and Masaya Notomi,
Frontiers in Optics (FiO 2021), FM2E.1, Virtual conference, November 2021. - Exceptional Point Transition of Electrically Pumped Photonic Crystal Nanolasers,
Kenta Takata, Kengo Nozaki, Eiichi Kuramochi, Shinji Matsuo, Koji Takeda, Takuro Fujii, Shota Kita, Akihiko Shinya and Masaya Notomi,
Frontiers in Optics (FiO 2019), FM4E.3, Washington, D.C., US, September 2019. - Topologically Insulating One-Dimensional Photonic Lattices Based on Gain and Loss,
Kenta Takata and Masaya Notomi,
International Summit on Optics, Photonics and Laser Technologies (Optics & Laser 2019), San Francisco, US, June 2019 [invited]. - Non-Hermiticity-Based Topological Insulating Phase of Light,
Kenta Takata and Masaya Notomi,
Progress In Electromagnetics Research Symposium (PIERS 2018), 4A13.3, Toyama, Japan, Aug 2018 [invited]. - Controllable Photonic Topological Insulating Chain Based on Non-Hermiticity,
Kenta Takata and Masaya Notomi,
Conference on Lasers and Electro-Optics (CLEO 2018), FM2Q.7, San Jose, US, May 2018. - Transport in PT-symmetric Coupled Resonator Waveguide based on Photonic Crystal Nanocavities,
Kenta Takata and Masaya Notomi,
The 24th Congress of the International Comission of Optics (ICO-24), Th3E-02, Tokyo, Japan, Aug 2017. - Parity-Time Symmetric Coupled Resonator Waveguide with Photonic Crystal Nanocavities,
Kenta Takata and Masaya Notomi,
The 21st OptoElectronics and Communications Conference (OECC2016), Niigata, Japan, Jul 2016.
Domestic conferences (Japanese)
- Designing non-Hermitian systems with Jordan normal form,
Kenta Takata, Adam Mock, Masaya Notomi and Akihiko Shinya,
The 71th JSAP Spring Meeting, 22p-11E-2, Tokyo, Japan, Mar 2024. - Excitation of anisotropic photonic crystal slabs for observing non-Hermitian skin effect,
Kenta Takata, Taiki Yoda, Yuto Moritake and Masaya Notomi,
The 84th JSAP Autumn Meeting, 21p-A308-7, Kumamoto, Japan, Sep 2023. - Optical non-Hermitian skin effect in semiconductor photonic crystal slab,
Kenta Takata, Taiki Yoda, Yuto Moritake and Masaya Notomi,
The 70th JSAP Spring Meeting, 16p-A501-3, Tokyo, Japan, Mar 2023. - Hexapole H1 photonic crystal nanocavities with measured Q factors exceeding one million,
Kenta Takata, Eiichi Kuramoshi, Akihiko Shinya and Masaya Notomi,
The 83rd JSAP Autumn Meeting, 20a-A101-3, Sendai, Japan, Sep 2022. - Non-Hermitian phenomena in coupled nanophotonic resonators,
Kenta Takata,
JPS 2022 Annual (77th) Meeting, 19aS10-8, Online Virtual Meeting, Mar 2022 [invited]. - Non-Hermitian coupled mode theory for cavity arrays with contrast of radiation loss,
Kenta Takata, Nathan Roberts, Akihiko Shinya and Masaya Notomi,
The 82nd JSAP Autumn Meeting, 12p-N321-4, Online Virtual Meeting, Sep 2021. - Non-Hermitian coupled mode theory for cavity arrays with gain and loss,
Kenta Takata, Nathan Roberts, Akihiko Shinya and Masaya Notomi,
The 68th JSAP Spring Meeting, 17p-Z31-5, Online Virtual Meeting, Mar 2021. - Observation of exceptional point degeneracy with electrically pumped photonic crystal lasers,
Kenta Takata, Kengo Nozaki, Eiichi Kuramochi, Shinji Matsuo, Koji Takeda, Takuro Fujii, Shota Kita, Akihiko Shinya and Masaya Notomi,
The 81th JSAP Autumn Meeting, 10p-Z18-4, Online Virtual Meeting, Sep 2020. - Hexapole mode of a H1 photonic crystal cavity with a high theoretical Q-factor,
Kenta Takata, Eiichi Kuramochi, Akihiko Shinya, Hideaki Taniyama, Shota Kita and Masaya Notomi,
The 66th JSAP Spring Meeting, 11p-W631-7, Tokyo, Japan, Mar 2019. - Suppression and revival of oscillation of electrically pumped photonic crystal nanolasers by PT phase transition,
Kenta Takata, Kengo Nozaki, Eiichi Kuramochi, Shinji Matsuo, Koji Takeda, Takuro Fujii, Shota Kita, Akihiko Shinya and Masaya Notomi,
The 79th JSAP Autumn Meeting, 19p-225B-12, Nagoya, Japan, Sep 2018. - [JSAP Young Scientist Award Speech] Photonic Topological Insulating Phase Induced by Gain and Loss,
Kenta Takata and Masaya Notomi,
The 78th JSAP Autumn Meeting, 7a-A410-1, Fukuoka, Japan, Sep 2017. - Photonic Topological Insulator Based on Si Photonic Crystal Resonator Array,
Kenta Takata and Masaya Notomi,
The 78th JSAP Autumn Meeting, 7a-A410-3, Fukuoka, Japan, Sep 2017. - Controllable One-Dimensional Photonic Topological Phase with PT-symmetry Breaking,
Kenta Takata and Masaya Notomi,
The 64th JSAP Spring Meeting, Yokohama, 15p-E205-5, Japan, Mar 2017.
Featured in Nature Photonics 11, 271 (2017). - Analysis of a photonic-crystal PT-symmetric coupled resonator waveguide based on buried heterostructure nanocavities,
Kenta Takata and Masaya Notomi,
The 63th JSAP Spring Meeting, 21p-S621-18, Tokyo, Japan, Mar 2016. - Control of group velocity with PT-symmetric coupled-resonator optical waveguide,
Kenta Takata and Masaya Notomi,
The 76th JSAP Autumn Meeting, 16a-2A-4, Nagoya, Japan, Sep 2015.
Awards
- Achievement Award, NTT-BRL Director's Awards of the fiscal year 2021,
for pioneering work on topological photonics (2022.3). - Outstanding Referee, American Physical Society (2021.2).
- Best Paper Award, NTT-BRL Director's Awards of the fiscal year 2018,
"Photonic Topological Insulating Phase Induced Solely by Gain and Loss" (2019.3). - Young Scientist Presentation Award, The Japanese Society of Applied Physics (2017.9).
Other web pages (including full publication list)
Association memberships
- American Physical Society (APS)
- Optica (formerly OSA)
- The Japan Society of Applied Physics (JSAP)
- The Physical Society of Japan (JPS)
Academic and professional experiences
- Research Scientist, NTT Basic Research Laboratories (2020.7 -)
- Researcher, NTT Basic Research Laboratories (2015.4 - 2020.6)
- Research Fellow (DC1), Japan Society for the Promotion of Science
(2012.4 - 2015.3) - Visiting Student Researcher, Stanford University
(2013.4 - 2013.9, 2010.10 - 2010.11) - Research Assistant, National Institute of Informatics (2010.4 - 2012.10)
- Participating Student, National Institute of Informatics (2012.11 - 2015.3)
- Intern, RIKEN (2013.11 - 2015.3)
Internship students
- Mr. Nathan Roberts (University of Bath, 2019.7 - 2019.12)
Refereeing activities
in Nature Photonics, Physical Review Letters, Optica, ACS Photonics, Physical Review Applied, Physical Review B, Optics Letters, Optics Express, Physical Review A, Scientific Reports, Applied Physics Express, Applied Optics, etc.
Education
Ph.D. course (2010.4 - 2015.3)
Department of Information and Communication Engineering,
Graduate School of Information Science and Technology,
University of Tokyo
Nat. Photon. 8, 937 (2014).
K. Takata, A. Marandi and Y. Yamamoto. PRA 92, 043821 (2015).
K. Takata et al. Sci. Rep. 6, 34089 (2016).
S. Utsunomiya, K. Takata and Y. Yamamoto. Opt. Exp. 19, 18091 (2011).
K. Takata, S. Utsunomiya and Y. Yamamoto. NJP 14, 013052 (2012).
K. Takata and Y. Yamamoto. PRA 89, 032319 (2014).
Undergraduate course (2009.4 - 2010.3)
Department of Electrical and Electronic Engineering,
School of Engineering,
University of Tokyo
