Demonstration of Real-Time Precision Optical Time Synchronization in a True Three-Node Architecture

TL;DR

This paper demonstrates a pioneering three-node optical clock network achieving real-time, high-precision synchronization over free-space channels, with potential applications in physics, communications, navigation, and geodesy.

Contribution

It presents the first multi-node optical clock network with real-time synchronization and 10 femtosecond precision, including an independent verification method.

Findings

Achieved 10 fs synchronization precision

Implemented a three-node hub-and-spoke optical network

Validated performance with out-of-loop verification

Abstract

Multi-node optical clock networks will enable future studies of fundamental physics and enable applications in quantum and classical communications as well as navigation and geodesy. We implement the first ever multi-node optical clock network with real-time, relative synchronization over free-space communication channels and precision on the order of 10 fs, realized as a three-node system in a hub-and-spoke topology. In this paper we describe the system and its performance, including a new, independent, out-of-loop verification of two-way optical time synchronization.