A hybrid solution for simultaneous transfer of ultrastable optical frequency, RF frequency and UTC time-tags over optical fiber

TL;DR

This paper presents a fiber-optic system capable of simultaneously distributing ultrastable optical frequencies, RF signals, and UTC time-tags with high stability, suitable for advanced time and frequency laboratories.

Contribution

It introduces a novel hybrid fiber-optic solution that stabilizes both optical and electrical signals against environmental disturbances for simultaneous distribution.

Findings

Optical transfer stability of 5e-18 at 100 s

RF transfer stability of 2e-15 at 100 s

Successful experimental demonstration of the system

Abstract

We describe a fiber-optic solution for simultaneous distribution of all signals generated at todays most advanced time and frequency laboratories, i.e. an ultrastable optical reference frequency derived from an optical atomic clock, a radio frequency precisely linked to a realization of the SI-Second, and a realization of an atomic timescale, being the local representation of the virtual, global UTC timescale. In our solution both the phase of the optical carrier and the delay of electrical signals (10 MHz frequency reference and one pulse-per-second time tags) are stabilized against environmental perturbations influencing the fiber link instability and accuracy. We experimentally demonstrate optical transfer stabilities of 5e-18 and 2e-15 for 100 s averaging period, for optical carrier and 10 MHz signals, respectively.