@article{11676,
  keywords = {frequency drift, optical cavity, optical lattice clock, ultrastable lasers},
  author = {John Robinson and Eric Oelker and William Milner and Wei Zhang and Thomas Legero and Dan-Gheorghita Matei and Fritz Riehle and Uwe Sterr and Jun Ye},
  title = {Crystalline optical cavity at 4  K with thermal-noise-limited instability and ultralow drift},
  abstract = {Crystalline optical cavities are the foundation of today\textquoterights state-of-the-art ultrastable lasers. Building on our previous silicon cavity effort, we now achieve the fundamental thermal-noise-limited stability for a 6\&nbsp;cm long silicon cavity cooled to 4\&nbsp;K, reaching\&nbsp;6.5\texttimes10<sup>-17</sup> from 0.8\&nbsp;s to 80\&nbsp;s. We also report for the first time, to the best of our knowledge, a clear linear dependence of the cavity frequency drift on incident optical power. The lowest fractional frequency drift of\&nbsp;-3\texttimes10<sup>-19</sup>/s is attained at a transmitted power of 40 nW, with an extrapolated drift approaching zero in the absence of optical power. These demonstrations provide a promising direction to reach a new performance domain for stable lasers, with stability better than\&nbsp;1\texttimes10<sup>-17</sup> and fractional linear drift below\&nbsp;1\texttimes10<sup>-19</sup>/s.},
  year = {2019},
  journal = {Optica},
  volume = {6},
  pages = {240},
  month = {2019-01},
  url = {https://www.osapublishing.org/optica/fulltext.cfm?uri=optica-6-2-240\&id=405188},
  doi = {10.1364/OPTICA.6.000240},
}