Shimadzu Review Vol.78[3・4](2021)
Development of Advanced Core Technology


Development of Laser Control Unit for Transportable Optical Lattice Clocks with 18-Digit Accuracy

by Takashi Muramatsu1Yuya Sakai1Tetsuo Furumiya, Ph. D.1Masao Takamoto, Ph. D.2Noriaki Ohmae, Assoc. Prof.3Ichiro Ushijima, Ph. D.4Hidetoshi Katori, Prof.2,4

Shimadzu Review 78[3・4] (2021)


An optical lattice clock is highly-accurate atomic clock and is one of the promising candidates for the redefinition of the second. Since the optical lattice clock can be applied not only to the time measurement but also to physical measure-ments such as relativistic geodesy, transportability for field use is desired. So far, stable operation outside the laboratory was difficult due to the complexity and size of the optical lattice clock, as it was not possible to achieve both downsiz-ing and high precision. The authors developed transportable strontium optical lattice clocks with a fractional uncertainty of 5.5 × 10-18. Shimadzu Corporation was in charge of developing the laser control unit. Developed optical lattice clocks were set on the ground floor and in the observation deck of Tokyo Skytree, to measure the relativistic time dilation   according to the height difference. The demonstration shows that the 18-digit precise optical lattice clocks are technical-ly ready to operate outside the laboratories, which opens new time-business, including relativistic physical measure-ment. 

1Advanced Analysis Unit, Technology Research Laboratory, Shimadzu Corporation, Kyoto, Japan
2Quantum Metrology Laboratory, RIKEN, Saitama, Japan
3Department of Applied Physics, Fukuoka University, Fukuoka, Japan
4Department of Applied Physics, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan

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