162 citations · 1.1k across the 21 of their papers we have counts for
21 papers
Search for ultralight dark matter from long-term frequency comparisons of optical and microwave atomic clocks
Takumi Kobayashi, Akifumi Takamizawa, Daisuke Akamatsu +8
We search for ultralight scalar dark matter candidates that induce oscillations of the fine structure constant, the electron and quark masses, and the quantum chromodynamics energy…
Erbium-doped-fiber-based broad visible range frequency comb with a 30 GHz mode spacing for astronomical applications
Keisuke Nakamura, Ken Kashiwagi, Sho Okubo +1
Optical frequency combs have the potential to improve the precision of the radial velocity measurement of celestial bodies, leading to breakthroughs in such fields as exoplanet exp…
Ultra-precise determination of thicknesses and refractive indices of optically thick dispersive materials by dual-comb spectroscopy
Kana A. Sumihara, Sho Okubo, Makoto Okano +2
Precise measurements of the geometrical thickness of a sample and its refractive index are important for materials science, engineering, and medical diagnosis. Among the possible n…
Demonstration of the nearly continuous operation of an Yb optical lattice clock for half a year
Takumi Kobayashi, Daisuke Akamatsu, Kazumoto Hosaka +6
Optical lattice clocks surpass primary Cs microwave clocks in frequency stability and accuracy, and are promising candidates for a redefinition of the second in the International S…
Improved Frequency Ratio Measurement with 87Sr and 171Yb Optical Lattice Clocks at NMIJ
Yusuke Hisai, Daisuke Akamatsu, Takumi Kobayashi +4
We report improved frequency ratio measurement with Sr and Yb optical lattice clocks at the National Metrology Institute of Japan (NMIJ). The Sr optical latti…
Uncertainty evaluation of an Yb optical lattice clock at NMIJ
Takumi Kobayashi, Daisuke Akamatsu, Yusuke Hisai +6
We report an uncertainty evaluation of an Yb optical lattice clock with a total fractional uncertainty of , which is mainly limited by the lattice-induce…