Optical Time Transfer Link between NIST and Mt. Blue Sky Connecting Yb-Lattice Clocks for Relativistic Geodesy

Oral

Abstract

We present an optical clock comparison over a hybrid optical network, consisting of a 69 km free-space link and an 81 km fiber link. This is an initial quantum sensor network demonstration from the Relativistic Redshift Peak-to-Plains (R2P2) collaboration. The network connects two independent neutral Yb-lattice clocks at two locations: the summit of Mt. Blue Sky (elevation 4300 m) and the NIST campus in Boulder, Colorado (elevation 1650 m), spanning a height difference of ~2700 m. During a technical shakedown in August 2025, the full optical network was operated phase-continuously with instabilities reaching a few parts in 10-17 at an averaging time of ~100 s. The R2P2 collaboration is currently performing additional network characterization over short testbed links targeting validation of fractional frequency instabilities and uncertainties at the 10-18 level. Results from these characterizations will also be presented.

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Presenters

  • Theodora Triano

    • University of Colorado, Boulder

Authors

  • Theodora Triano

    • University of Colorado, Boulder

  • Roger Brown

  • Emily Caldwell

    • National Institute of Standards and Technology (NIST)

  • Christopher Dennis

  • Jean-Daniel Deschenes

  • Scott Diddams

    • University of Colorado, Boulder

  • Fabrizio Giorgetta

  • Tanner Grogan

    • University of Colorado, Boulder

  • Adam Halaoui

  • Benjamin Hunt

  • Andrew Ludlow

  • Harikesh Ranganath

  • Laura Sinclair

  • William Swann

  • Eric Swiler

  • Skyler Weight

  • Derek Van Westrum

  • Tsung-Han Wu