In this paper, we experimentally investigate a novel feedback loop scheme to generate optical frequency comb with varying free spectral range (FSR) spacing in a high-Q silicon nitride (Si₃N₄) micro-ring resonator. By selecting and amplifying different feedback sidebands, comb line spacing varying from 1-fold to 6-fold FSRs is successfully achieved. This approach could be beneficial to tune the comb repetition rate which is an important parameter for many applications, such as optical coherent communications, optical metrology and arbitrary waveform generation.

中文翻译：

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基于Si 3 N 4微谐振器的FSR间隔变化的Kerr频率梳

在本文中，我们通过实验研究了一种新颖的反馈环路方案，以在高Q氮化硅（Si ₃ N ₄）微环谐振器中生成具有变化的自由光谱范围（FSR）间隔的光频率梳。通过选择和放大不同的反馈边带，梳状线间距成功实现了从1倍到6倍FSR的变化。这种方法对于调整梳状重复率可能是有益的，梳状重复率对于许多应用（例如光学相干通信，光学计量和任意波形生成）是重要的参数。