Related Experiment Video
Updated: Jun 25, 2026

Implementation of a Reference Interferometer for Nanodetection
Published on: April 26, 2014
Measuring the frequency of a Sr optical lattice clock using a 120 km coherent optical transfer
F-L Hong1, M Musha, M Takamoto
1National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technologies, Tsukuba, Ibaraki, Japan. f.hong@aist.go.jp
Abstract:
We demonstrate a precision frequency measurement using a phase-stabilized 120 km optical fiber link over a physical distance of 50 km. The transition frequency of the (87)Sr optical lattice clock at the University of Tokyo is measured to be 429228004229874.1(2.4) Hz referenced to international atomic time. The results demonstrate the excellent functions of the intercity optical fiber link and the great potential of optical lattice clocks for use in the redefinition of the second.

