About Project

Katori Hidetoshi

Hidetoshi Katori (Program Manager)

Professor, Graduate School of Engineering,
The University of Tokyo

Chief Scientist, Quantum Metrology Laboratory,

The optical lattice clock, taken as a ridiculous idea in 2001, has come true and changed the game for building highly precise and stable atomic clocks. In this project, we will develop a space-time information platform by networking “optical lattice clocks”, which improve the uncertainty of atomic clocks used in GNSS (Global Navigation Satellite System) by three orders of magnitude. Such a platform will benefit future high-capacity network systems, navigation, and other services.



A site visit of the project was held as a hybrid of online and on-site, hosted by Shimadzu Technology Research Laboratory.
Link updated.
Space-time information platform with a cloud of optical lattice clocks Links
Mr. Takafumi Horie, an entrepreneur and investor, posted his impressions of his visit to Katori Lab on the content delivery platform "note".
Optical lattice clocks leads to new space business
Press release from the National Institute of Advanced Industrial Science and Technology (AIST). Direct excitation of clock transitions at wavelengths of ytterbium atoms has been observed, and the absolute frequency of these transitions has been successfully measured for the first time in the world. The newly measured absolute frequency of the clock transition can be incorporated into optical lattice clocks to suppress time base fluctuations caused by environmental disturbances and contribute to their higher accuracy.
・Press Release(Japanese):
Succeeded in precise spectroscopy of clock transitions with high sensitivity to environmental disturbances to further improve the precision of optical lattice clocks   - Accelerate discussion on Redefining the Second -
 Akio Kawasaki, Takumi Kobayashi, Akiko Nishiyama, Takehiko Tanabe, and Masami Yasuda,
 Observation of the 4f146s2 1S0−4f135d6s2(J=2) clock transition at 431 nm in Yb,
 Phys. Rev. A 107, L060801.
A new paper is now available.
Ryoto Takeuchi, Hayaki Chiba, Shoichi Okaba, Masao Takamoto, Shigenori Tsuji and Hidetoshi Katori,
Continuous outcoupling of ultracold strontium atoms combining three different traps,

The Japan Society of Applied Physics.
Program Manager Katori visited the Quantum Technology Hub in the UK, where the ICON project is underway, and received a great welcome.
・Professor Katori’s visit to the Quantum Technology Hub marks new milestone in quantum clocks project
・Professor Katori’s visit to the Quantum Technology Hub marks new milestone in ICON project
SPIE's online article on "Quantum Clock" introduces Program Manager Katori's achievements and research.
・Quantum clocks: Ticking away toward a new era of precision measurement
Happy New Year!
We look forward to working with you in the New Year.
A project workshop was held at RIKEN.
AIST and Yokohama National University have issued a press release on their search for dark matter using two high-precision atomic clocks, an ytterbium optical lattice clock and a cesium microwave atomic clock. The paper was also published in the Physical Review Letters.
・Press Release(Japanese):
 Search for Dark Matter with Optical Lattice Clock and Cesium Microwave Atomic Clock
 - Simultaneous and High-utilization Operation of "Redefinition Candidate" and "Current Definition Leader" of Seconds Contributing to International Atomic Time is the Key -
 T. Kobayashi, A. Takamizawa, D. Akamatsu, A. Kawasaki, A. Nishiyama, K. Hosaka, Y. Hisai, M. Wada, H. Inaba, T. Tanabe, and M. Yasuda,
 Search for Ultralight Dark Matter from Long-Term Frequency Comparisons of Optical and Microwave Atomic Clocks,
 Phys. Rev. Lett. 129, 241301 – Published 7 December 2022.

Professor Katori of the program manager, received the
"Honda Prize 2022", an international academic award.
Professor Katori of the program manager was highly awarded for his Invention of the “optical lattice clock” which is 1,000 times more accurate than conventional atomic clocks and deviates only one second in 30 billion years.

・Press release from the Honda Foundation
・About the Honda Prize
・Press release from the University of Tokyo
A site visit of the project was held as a hybrid of online and on-site, hosted by NTT Basic Research Laboratories.
The papers by Omae, Sakama, and Katori received the Excellent Paper Award from the Institute of Electrical Engineers of Japan, Electronics, Information, and Systems Division.
・Award: 2022 Electronic, Information and Systems Category Magazine Excellent Paper Award
・Authors: Nobuaki Omae (RIKEN), Toshiaki Sakuma (University of Tokyo), Hidetoshi Katori (University of Tokyo, RIKEN)
・Title: Full fiber transmission of high-precision frequency transmission of optical lattice clocks (Vol.139, No2, p.126-130, 2019)
There was a press release from the National Institute of Information and Communications Technology (NICT) that they succeeded in generating standard time for the first time in the world by referring to an optical lattice clock that operates intermittently.
・The world's first use of an optical lattice clock to maintain national standard time
~ Synchronization with Coordinated Universal Time is possible only with the clock owned by NICT ~
There was a press release from Astamuse Co., Ltd. to participate in our project.
・Decided to participate in the research project "Space-time information platform with a cloud of optical lattice clocks" in the JST-Mirai Program
At the TOKYO SKYTREE Tembo Deck, a video exhibition of experiments using optical lattice clocks has begun.
・Press Release of the TOKYO SKYTREE
・Technology exhibition at the TOKYO SKYTREE Tembo Deck (RIKEN Channel)

A new group "Social Implementation research group" was established in the project, and astamuse company,Ltd. participated as a new member.
The judgement result of the 1st Stage Gate have been released. The result of judgement is
  [Result] Passing through the 1st Stage Gate
  [Overview] Score S: Satisfies the evaluation criteria, and particularly excellent points are recognized.
We ware able to pass with the highest result of judgement.
・Large Scale Type project mid-term evaluation (Japanese)
The latest issue of Nature Photonics posted an interview with Professor Katori, a program manager who won the Breakthrough Prize.
・Ever-evolving optical lattice clocks
・Nature Photonics, Volume 16 Issue 1, January 2022


The Optical Lattice Clock (NICT-Sr1, NMIJ-Yb1) of the RS Group(NICT, AIST) was introduced in NEWS of the Bureau of Weights and Measures(BIPM). The significant contribution of the RS Group has been recognized.
"Record number of frequency standards contribute to International Atomic Time"
The project 1st Stage Gate judgement meeting was held. The results of 1st Stage Gate activities and 2nd Stage Gate plans for future continuation were evaluated, and whether or not the project could be continued after April 2022 was deliberated. The results will be announced in February 2022.
A workshop of the project was held on Nobember 2.

Professor Katori of the program manager, received the
"Breakthrough Prize in Fundamental Physics",
an international academic award.
The invention and development of the optical lattice clocks that enables precision tests of the fundamental laws of nature have been greatly recognized.

・Press release from the Breakthrough Prize
・prizewinner(Breakthrough Prize)
・Press release from RIKEN
・Press release from the University of Tokyo
・Press release from the University of Tokyo(Engineering)
・Press release from the University of Tokyo(Applied Physics)

Adopted on the cover of Adovanced Quantum Technologies.
The achievement page have been updated.
The site visit of our project was held on June 4 at a video conference with Shimadzu Corporation as the host site.

An interview with Katori Program Manager is published in the March 2021 issue of Nikkei Electronics (P54).
Nikkei Electronics March 2021(Japanese)

Dr. Takamoto, assistant program manager,
Received the "3rd (2020) Teruo Hiruma Optical Science Award".

・Press release from Research Foundation
  for Opto-Science and Technology(Japanese)

・Press release from RIKEN(Japanese)


past news Past News (2019/12/2~2020/12/21)

Contact us

Space-time information platform with a cloud of optical lattice clocks

2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656, JAPAN
Faculty of Engineering Bldg.9
Katori Laboratory
Room no.507

Tel: +81-3-5841-6845
Fax: +81-3-5841-6859
E-mail: jst.katori.hq(at)gmail.com











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Last update
November 16, 2023