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Christopher Flower, Mahmoud Mehrabad, Lida Xu, Gregory Moille, Daniel Suarez-Forero, Yanne Chembo, Sunil Mittal, Kartik Srinivasan, Mohammad Hafezi
Abstract
On-chip generation of optical frequency combs using nonlinear ring resonators has enabled numerous applications of combs that were otherwise limited to mode-locked lasers. Nevertheless, on-chip frequency combs have relied predominantly on single-ring resonators. In this study, we experimentally demonstrate the generation of a novel class of frequency combs, the topological frequency combs, in a two-dimensional lattice of hundreds of ring resonators that hosts fabrication-robust topological edge states with linear dispersion. By pumping these edge states, we demonstrate the generation of a nested frequency comb that shows oscillation of multiple edge state resonances across ≈40 longitudinal modes and is spatially confined at the lattice edge. Our results provide an opportunity to explore the interplay between topological physics and nonlinear frequency comb generation in a commercially available nanophotonic platform.
Flower, C.
, Mehrabad, M.
, Xu, L.
, Moille, G.
, Suarez-Forero, D.
, Chembo, Y.
, Mittal, S.
, Srinivasan, K.
and Hafezi, M.
(2024),
Observation of topological frequency combs, Science/AAAS, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=957206
(Accessed October 9, 2025)