Mode interaction aided excitation of dark solitons in microresonators constructed of normal dispersion waveguides

• Published in: arXiv.org
• Main Authors: Xue, Xiaoxiao, Yi Xuan, Liu, Yang, Wang, Pei-Hsun, Chen, Steven, Wang, Jian, Leaird, Dan E, Qi, Minghao, Weiner, Andrew M
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 17.08.2015
• Subjects: Excitation; Locking; Physics - Optics; Simulation; Solitary waves; Stability; Waveguides
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1404.2865

Kerr frequency combs from microresonators are now extensively investigated as a potentially portable technology for a variety of applications. Most studies employ anomalous dispersion microresonators that support modulational instability for comb initiation, and mode-locking transitions resulting in coherent bright soliton-like pulse generation have been reported. However, some experiments show comb generation in normal dispersion microresonators; simulations suggest the formation of dark pulse temporal profiles. Excitation of dark pulse solutions is difficult due to the lack of modulational instability in the effective blue-detuned pumping region; an excitation pathway has been demonstrated neither in experiment nor in simulation. Here we report experiments in which dark pulse combs are formed by mode-interaction-aided excitation; for the first time, a mode-locking transition is observed in the normal dispersion regime. The excitation pathway proposed is also supported by simulations.