Phys.org  June 20, 2024 On-chip frequency combs have relied predominantly on single-ring resonators. A team of researchers in the US (University of Maryland, University of Illinois, Northeastern University) experimentally demonstrated the generation of 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, they demonstrated the generation of a nested frequency comb that showed oscillation of multiple edge state resonances across ≈40 longitudinal modes and was spatially confined at the lattice edge. According to the researchers their results provide an opportunity to explore the […]