A Transportable Ytterbium Optical Lattice Clock With Eighteen Digits of Accuracy

Abstract

This thesis presents the development and uncertainty evaluation of a transportable ytterbium optical lattice clock, achieving a total systematic uncertainty level of 3.7 × 10⁻¹⁸. Built into a compact rack-mounted design, this clock combines portability with high accuracy, suitable for a range of scientific applications. A detailed examination of the clock’s construction and operational mechanisms is provided, highlighting the integration of technologies that facilitate its transportability without compromising accuracy and providing guidance to future users. The uncertainty budget is emphasized, describing the details of each measurement needed to characterize the systematic shifts on the clock frequency. In addition, this thesis encompasses a field test conducted at the US Naval Observatory, demonstrating the system’s robustness and reliability in transportation and operation under varied conditions. This work not only sets a new standard in portable optical lattice clock technology, but also demonstrates the clock’s utility in advancing global timekeeping and geodetic measurements with near-centimeter resolution, significantly contributing to the fields of relativistic geodesy and the potential redefinition of the SI second.