Silica microcombs have a high potential for generating tens of gigahertz of optical pulse trains with ultralow timing jitter, which is highly suitable for higher speed and higher bandwidth information systems. So far, the accurate characterization of timing jitter in microcombs has been limited by the measurement methods—although theoretically predicted to be ${\gt}{20 {\rm dB}}$ better performance, the true performance has not been accurately measured until now. Here, using a self-heterodyne-based measurement method with ${20}\;{{\rm zs/Hz}^{1/2}}$ resolution, we show that 2.6-fs rms timing jitter is possible for 22-GHz silica microcombs. We identified their origins, which suggests that silica microcombs may achieve 200-as-level jitter by better intensity noise control. This jitter performance can greatly benefit many high-speed and high-bandwidth applications including analog-to-digital conversion, microwave generation, and optical communications.

中文翻译：

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超低抖动二氧化硅微梳

二氧化硅微梳具有很高的潜力，可产生数十千兆赫兹的具有超低定时抖动的光脉冲序列，非常适合更高速度和更高带宽的信息系统。到目前为止，微梳状结构中的定时抖动的精确表征受到测量方法的限制-尽管理论上预测它的性能要好$ {\ gt} {20 {\ rm dB}} $，但是直到真正的性能才能得到准确的测量现在。在这里，使用基于自我外差的测量方法，并使用$ {20} \; {{\ rm zs / Hz} ^ {1/2}} $分辨率，我们表明对于22 GHz硅胶微梳，2.6 fs rms的定时抖动是可能的。我们确定了它们的起源，这表明二氧​​化硅微梳通过更好的强度噪声控制可以达到200级的抖动。这种抖动性能可以极大地使许多高速和高带宽应用受益，包括模数转换，微波产生和光通信。