Hybridization of Kerr Solitons in Coupled Microresonators

Hybridization of physical systems is a fundamental phenomenon responsible for the formation of complex structures in nature, as illustrated by the well-known omnipresent linear mixing of atomic orbitals [1].Nonlinear interactions result in fundamentally different hybridized states emerging beyond the conventional superposition of the system components.In optics, the coupling of nonlinear soliton coherent states of light has recently been experimentally demonstrated, promising various applications in the development of photonic devices [2-5].We report theoretical prediction of a novel phenomenon in nonlinear photonics: the formation of hybridized dissipative Kerr solitons (DKS) in coupled microresonator systems [6].This research reveals a fundamentally new type of coherent light states that cannot be generated in single-component setups.The system under investigation consists of two coupled optical microresonators with opposite dispersion properties (normal and anomalous) and equal free spectral range.The key feature of this configuration is the ability to create hybridized dispersion landscapes through inter-resonator coupling.The main findings demonstrate the observation of fully coherent soliton states in both resonators, formed via an unconventional four-wave mixing process.These hybridized solitons generate unique optical frequency combs characterized by flat-topped spectra near the pump frequency and high-power spectral lines (see Fig. 1).