Strontium optical lattice clocks for practical realization of the metre and secondary representation of the second

TL;DR

This paper demonstrates a practical system of two independent strontium optical lattice clocks, achieving high stability and frequency verification, advancing the realization of the metre and secondary second standards.

Contribution

It introduces a dual-strontium optical lattice clock system with shared laser probing and frequency verification via optical comb and GPS, enhancing practical timekeeping standards.

Findings

Hertz-level spectroscopy of the clock transition

Frequency stability measurements of the clocks

Verification of absolute frequency using optical comb and GPS

Abstract

We present a system of two independent strontium optical lattice standards probed with a single shared ultra-narrow laser. The absolute frequency of the clocks can be verified by the use of Er:fiber optical frequency comb with the GPS-disciplined Rb frequency standard. We report hertz-level spectroscopy of the clock line and measurements of frequency stability of the two strontium optical lattice clocks.