Investigation of mode coupling in normal-dispersion silicon nitride microresonators for Kerr frequency comb generation

By Yang Liu, Yi Xuan, Xiaoxiao Xue, Pei-Hsun Wang, S. Chen, A. Metcalf, Jian Wang, Daniel E. Leaird, Minghao Qi, Andrew M. Weiner. 2014

222 citations recorded by the source corpus.

Kerr frequency combs generated from microresonators are the subject of intense study for potential applications ranging from short pulse generation to frequency metrology to radiofrequency signal processing. Most research employs microresonators with anomalous dispersion, for which modulation instability is believed to play a key role in initiation of the comb. Comb generation in normal-dispersion microresonators has also been reported but is less well understood. Here, we report a detailed investigation of few-moded, normal-dispersion silicon nitride microresonators, showing that mode coupling can strongly modify the local dispersion, even changing its sign. We demonstrate a link between mode coupling and initiation of comb generation by showing experimentally the pinning of one of the initial comb sidebands near a mode-crossing frequency. Associated with this route to comb formation, we observe direct generation of coherent, bandwidth-limited pulses at repetition rates down to 75 GHz, without the need to first pass through a chaotic state. Our results with normal-dispersion devices highlight mode interactions as a beneficial tool for comb initiation and pulse formation.

Subfields: Atomic and Molecular Physics, and Optics, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/3713aca9f646915056a3a90a2ee5b6721d608441

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In Atomic and Molecular Physics, and Optics

In Electrical and Electronic Engineering

Citations in the corpus

RF Photonics: An Optical Microcombs’ Perspective (2018, unknown): “By exploiting mode interactions between coupled Si3N4 MRRs, optical micro-combs have been generated even in 300-nm-thick Si3N4 devices with normal dispersion [47], [94]–[98].”
Micro-combs: A novel generation of optical sources (2017, methodology): “further investigated [137] mode coupling in few-moded, normal GVD Si3N4 micro-resonators.”
Dispersion engineering and measurement of whispering gallery mode microresonator for Kerr frequency comb generation (2020, background): “Moreover, the higher conversion efficiency [117] and FSR controllability [65, 118, 119] are unique features of the normal dispersion microcomb.”