Synchronization of non-solitonic Kerr combs

TL;DR

This paper demonstrates all-optical synchronization of Kerr frequency combs in the non-solitonic, normal-GVD regime, expanding the understanding of Kerr comb synchronization beyond the soliton regime and enabling efficient, flat-spectrum comb generation.

Contribution

It introduces the first demonstration of Kerr comb synchronization in the non-solitonic, normal-GVD regime, showing universality and potential for high-power, flat-spectrum combs.

Findings

Achieved phase-locked Kerr combs in the normal-GVD regime.

High pump-to-comb conversion efficiencies observed.

Spectrally flat comb profiles with high line powers.

Abstract

Synchronization is a ubiquitous phenomenon in nature that manifests as the spectral or temporal locking of coupled nonlinear oscillators. In the field of photonics, synchronization has been implemented in various laser and oscillator systems, enabling applications including coherent beam combining and high precision pump-probe measurements. Recent experiments have also shown time-domain synchronization of Kerr frequency combs via coupling of two separate oscillators operating in the dissipative soliton [i.e., anomalous group-velocity dispersion (GVD)] regime. Here, we demonstrate all-optical synchronization of Kerr combs in the non-solitonic, normal-GVD regime in which phase-locked combs with high pump-to-comb conversion efficiencies and relatively flat spectral profiles are generated. Our results reveal the universality of Kerr comb synchronization and extend its scope beyond the soliton regime, opening a promising path towards coherently combined normal-GVD Kerr combs with spectrally flat profiles and high comb-line powers in an efficient microresonator platform.