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arXiv · 2409.13512

Cold Beam Optical Clock with Multifrequency Spectroscopy

William G. Tobias·Bryan Hemingway·Steven Peil
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Abstract

We demonstrate an optical clock based on Ramsey-Bord\'e interferometry in a laser-cooled ${}^{40}$Ca beam. The mean velocity is reduced by an order of magnitude relative to a thermal beam and the transverse temperature approaches the Doppler limit, enabling the measurement of sub-kHz linewidth fringes in a compact interferometer. Using tailored phase and intensity modulation of the spectroscopy laser to add uniform frequency sidebands, we interrogate atoms throughout the transverse velocity distribution, increasing the Ramsey-Bord\'e fringe amplitude by a factor of 14 and improving the Allan deviation to $3.4\times 10^{-15}$ at one second averaging time.

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William G. Tobias, Bryan Hemingway, Steven Peil. 2024-09-20. Cold Beam Optical Clock with Multifrequency Spectroscopy. https://doi.org/10.1103/physrevlett.134.043401

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