Dynamics of dark breathers and Raman-Kerr frequency combs influenced by high-order dispersion

We investigate the dark breathers and Raman-Kerr microcombs generation influenced by stimulated Raman scattering (SRS) and high-order dispersion (HOD) effects in silicon microresonators with an integrated spatiotemporal formalism. The strong and narrow Raman gain constitute a threshold behavior with respect to free spectral range above which stable dark pulses can exist. The breathing dark pulses induced by HOD mainly depend on the amplitude and sign of third-order dispersion coefficient and their properties are also affected by the Raman assisted four wave mixing process. Such dissipative structures formed through perturbed switching waves, mainly exist in a larger red detuning region than that of stable dark pulses. Their breathing characteristics related to driving conditions have been analyzed in detail. Furthermore, the octave spanning mid-infrared (MIR) frequency combs via Cherenkov radiation are demonstrated, which circumvent chaotic and multi-soliton states compared with their anomalous dispersion-based counterpart. Our findings provide a viable way to investigate the physics inside dark pulses and broadband MIR microcombs generation. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

The study focuses on the generation of dark breathers and Raman-Kerr microcombs in silicon microresonators, influenced by stimulated Raman scattering and high-order dispersion effects. The results show that Raman gain exhibits a threshold behavior, while breathing dark pulses are mainly dependent on the amplitude and sign of the third-order dispersion coefficient. Additionally, the demonstration of octave-spanning mid-infrared frequency combs via Cherenkov radiation suggests a viable way to investigate physics within dark pulses and broadband MIR microcombs.