On-chip multi-timescale spatiotemporal optical synchronization

Published

September 12, 2025

Author(s)

Lida Xu, Mahmoud Mehrabad, Christopher Flower, Gregory Moille, Alessandro Restelli, Daniel Suarez-Forero, Yanne Chembo, Sunil Mittal, Kartik Srinivasan, Mohammad Hafezi

Abstract

Mode locking is foundational to nonlinear optics, enabling advances in metrology, spectroscopy, and communications. However, it remains unexplored in nonharmonic, multi-timescale regimes. Here, we realize on-chip multi-timescale synchronization using topological photonics. We design a two-dimensional lattice of 261 coupled silicon nitride ring resonators that supports nested mode-locked states with fast ( approximately 1 terahertz) single-ring and slow ( approximately 3 gigahertz) topological super-ring timescales. We observe clear signatures of multi-timescale mode locking, including a quadratic distribution of pump noise across both azimuthal mode families, consistent with theory. These findings are supported by near-transform–limited repetition beats and the emergence of periodic temporal patterns on the slow timescale. The edge-confined states show distinct dynamics from bulk and single-ring modes, enabling clear identification. Our results establish topological frequency combs as a robust platform for independently tunable, lattice-scale synchronization, opening new directions for exploring the interplay of nonlinearity and topology in integrated photonics.

Citation

Science Advances

Volume

11

Pub Type

Journals

Download Paper

https://doi.org/10.1126/sciadv.adw7696

Local Download

Citation

Xu, L. , Mehrabad, M. , Flower, C. , Moille, G. , Restelli, A. , Suarez-Forero, D. , Chembo, Y. , Mittal, S. , Srinivasan, K. and Hafezi, M. (2025), On-chip multi-timescale spatiotemporal optical synchronization, Science Advances, [online], https://doi.org/10.1126/sciadv.adw7696, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=959090 (Accessed October 8, 2025)