We experimentally demonstrate Kerr optical frequency combs (OFCs) with mode spacing of 1, 2, 3, 5, 6, and 8 free spectral ranges (FSRs) corresponding to 0.4, 0.8, 1.2, 2, 2.4, and 3.2 THz, respectively, in silica microspheres pumped by CW C-band lasers in the anomalous dispersion range. Experimental realizations are based on using standard telecom equipment and components such as SMF-28e fiber for producing microspheres and fiber tapers for pump coupling and OFC outcoupling. Numerical simulation is performed to support the experimental results and explain the observed spectral asymmetry in OFCs by the influence of the 3rd-order dispersion.

中文翻译：

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二氧化硅微球中具有多FSR模式间距的Kerr光频梳

我们通过实验证明了模式间隔为1、2、3、5、6和8的自由光谱范围（FSR）分别对应于0.4、0.8、1.2、2、2.4和3.2 THz的Kerr光学频率梳（OFC），在反常色散范围内被连续波C波段激光器泵浦的二氧化硅微球中的碳纳米管。实验实现基于使用标准电信设备和组件（例如用于生产微球的SMF-28e光纤）和用于泵浦耦合和OFC外耦合的光纤锥度。进行数值模拟以支持实验结果，并通过三阶色散的影响解释在OFC中观察到的光谱不对称性。