Synchronization of coupled optical microresonators

TL;DR

This paper demonstrates experimental synchronization of two distant chip-based frequency combs, following the Kuramoto model, enabling coherent combination and overcoming power limits, with implications for integrated photonics and nonlinear systems.

Contribution

It provides the first experimental demonstration of synchronization of coupled microresonator frequency combs over long distances, following the Kuramoto model.

Findings

Synchronization obeys the Kuramoto model.

Coherent combination overcomes power limits.

Potential for scalable integrated photonic systems.

Abstract

The phenomenon of synchronization occurs universally across the natural sciences and provides critical insight into the behavior of coupled nonlinear dynamical systems. It also offers a powerful approach to robust frequency or temporal locking in diverse applications including communications, superconductors, and photonics. Here we report the experimental synchronization of two coupled soliton modelocked chip-based frequency combs separated over distances of 20 m. We show that such a system obeys the universal Kuramoto model for synchronization and that the cavity solitons from the microresonators can be coherently combined which overcomes the fundamental power limit of microresonator-based combs. This study could significantly expand applications of microresonator combs, and with its capability for massive integration, offers a chip-based photonic platform for exploring complex nonlinear systems.