Spatiotemporal mode-locking and photonic flywheel in multimode microresonators

TL;DR

This paper introduces a novel spatiotemporal mode-locking (STML) in dissipative Kerr soliton microcombs within a high-Q multimode fiber resonator, achieving ultralow noise and high coherence for advanced photonic applications.

Contribution

First demonstration of STML DKS in a high-Q multimode fiber microresonator, combining DKS and STML principles for ultrahigh coherence and ultralow jitter microcombs.

Findings

Achieved fundamental comb linewidth of 400 mHz.

Demonstrated DKS timing jitter of 500 attoseconds.

Enhanced photonic flywheel performance with ultrahigh coherence.

Abstract

Dissipative Kerr soliton (DKS) frequency combs - also known as microcombs - have arguably created a new field in cavity nonlinear photonics, with a strong cross-fertilization between theoretical, experimental, and technological research. Spatiotemporal mode-locking (STML) not only add new degrees of freedom to ultrafast laser technology, but also provide new insights for implementing analogue computers and heuristic optimizers with photonics. Here, we combine the principles of DKS and STML for the first time to demonstrate the STML DKS by developing an unexplored ultrahigh-quality-factor Fabry-Perot microresonator based on graded index multimode fiber (GRIN-MMF). Using the intermodal stimulated Brillouin scattering, we can selectively excite either the eigenmode DKS or the STML DKS. Furthermore, we demonstrate an ultralow noise microcomb that enhances the photonic flywheel performance in both the fundamental comb linewidth and DKS timing jitter. The demonstrated fundamental comb linewidth of 400 mHz and DKS timing jitter of 500 attosecond represent improvements of 25x and 2.5x, respectively, from the state-of-the-art. Our results show the potential of GRIN-MMF FP microresonators as an ideal testbed for high-dimensional nonlinear cavity dynamics and photonic flywheel with ultrahigh coherence and ultralow timing jitter.