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arXiv · 2207.08679

A transportable clock laser system with an instability of $1.6 \times 10^{-16}$

Sofia Herbers·Sebastian Häfner·Sören Dörscher·Tim Lücke·Uwe Sterr·Christian Lisdat
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Abstract

We present a transportable ultra-stable clock laser system based on a Fabry-Pérot cavity with crystalline Al$_{0.92}$Ga$_{0.08}$As/GaAs mirror coatings, fused silica (FS) mirror substrates and a 20~cm-long ultra-low expansion (ULE\textsuperscript{\textregistered}) glass spacer with a predicted thermal noise floor of $\mathrm{mod}\,σ_\mathrm{y} = 7 \times 10^{-17}$ in modified Allan deviation at one second averaging time. The cavity has a cylindrical shape and is mounted at ten points. Its measured sensitivity of the fractional frequency to acceleration for the three Cartesian directions are $2(1) \times 10^{-12}$/(ms$^{-2}$), $3(3) \times 10^{-12}$/(ms$^{-2}$) and $3(1) \times 10^{-12}$/(ms$^{-2}$), which belong to the lowest acceleration sensitivities published for transportable systems. The laser system's instability reaches down to $\mathrm{mod}\,σ_\mathrm{y} = 1.6 \times 10^{-16}$

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Sofia Herbers, Sebastian Häfner, Sören Dörscher, Tim Lücke, Uwe Sterr, Christian Lisdat. 2022-10-20. A transportable clock laser system with an instability of $1.6 \times 10^{-16}$. https://doi.org/10.1364/ol.470984

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