Second-harmonic-assisted four-wave mixing in chip-based microresonator frequency comb generation

• 来源期刊: 光：科学与应用（英文版）
• 关键词: four-wave mixing Kerr frequency comb microresonator second-harmonic generation
• 年，卷（期）: 2017,（2）
• 页码范围: 127-135
• 页数: 9页
• 语种: 英文
• DOI: 10.1038/lsa.2016.253

摘要

Simultaneous Kerr comb formation and second-harmonic generation with on-chip microresonators can greatly facilitate comb self-referencing for optical clocks and frequency metrology.Moreover,the presence of both second-and third-order nonlinearities results in complex cavity dynamics that is of high scientific interest but is still far from being well-understood.Here,we demonstrate that the interaction between the fundamental and the second-harmonic waves can provide an entirely new way of phase matching for four-wave mixing in optical microresonators,enabling the generation of optical frequency combs in the normal dispersion regime under conditions where comb creation is ordinarily prohibited.We derive new coupled time-domain mean-field equations and obtain simulation results showing good qualitative agreement with our experimental observations.Our findings provide a novel way of overcoming the dispersion limit for simultaneous Kerr comb formation and second-harmonic generation,which might prove to be especially important in the near-visible to visible range where several atomic transitions commonly used for the stabilization of optical clocks are located and where the large normal material dispersion is likely to dominate.