Optical Lattice Clock : A Novel Tool for Precision Optical-Frequency Measurements(Current Topics)

Masao Takamoto, Hidetoshi Katori

Nathaniel B. Phillips, K. Beloy, N. Hinkley +4 more

Masao Takamoto

In recent years, with such rapid progress in laser technology as optical frequency combs, stable laser

Michael E. Boyd, Andrew D. Ludlow, Seth M. Foreman +7 more

Results from the JILA optical lattice clock are presented. We report on our development of precision tools for the lattice clock, including a stabilized clock laser with sub-Hz linewidth, fs-comb based technology allowing accurate clock comparison in both the microwave and optical domains, and clock transfer over optical fiber in an urban environment. High resolution spectroscopy (Q > 2 times 1014) of lattice confined strontium atoms is used for both a high-performance optical clock and atomic structure measurements. The current accuracy and stability of the lattice clock are also discussed.

Takumi Kobayashi

Haosen Shi, BINGKUN LU, Huaqing Zhang +12 more

Optical frequency ratio measurement between optical atomic clocks is essential to precision measurement as well as the redefinition of the second. Currently, the statistical noise in frequency ratio measurement of most ion clocks is limited by the frequency instability of ion clocks. In this work, we reduce the statistical noise in the frequency ratio measurement between a transportable Ca + optical clock and a Sr optical lattice clock down to 2.2×10 −15 / τ . The local oscillator of the Ca + optical clock is frequency-synthesized from the Sr optical lattice clock, enabling a longer probe time for Ca + clock transition. Compared to previous measurement using independent local oscillators, we achieve 10-fold reduction in comparison campaign duration.