AI 中文总结
研究芯片级微梳稳定性难题，提出基于自注入锁定的自稳定机制，通过选择泵浦频率噪声与反馈强度抑制重复率波动，实现微梳超低相位噪声、低定时抖动，在氮化硅孤子微梳中取得优异性能，为芯片级精密计量开拓新途径。
AI 中文摘要
光学频率梳形成由重复率和频率偏移两个自由度完全定义的等距排列的锁相谱线。将这些参数稳定到公共频率参考会产生一个相干频率标尺，这对现代精密计量至关重要。然而，将这种稳定性扩展到芯片级微梳仍然是一个突出挑战。在此，我们展示了一种基于通过外部反馈回路对选定梳状线进行自注入锁定的自稳定机制。该过程除了泵浦之外还建立了第二个锚点，从而限制了梳状频率噪声动态。我们表明，通过在泵浦频率噪声和反馈强度之间进行适当选择，重复率的集体波动会受到强烈抑制。结果是微梳表现出超低相位噪声和大幅降低的定时抖动。在100GHz氮化硅孤子微梳中，我们实现了高转换效率、整个C波段亚赫兹本征线宽和1fs的积分定时抖动的前所未有的组合。这种方法能够实现具有出色噪声性能和飞秒级脉冲稳定性的芯片级微梳，超越传统噪声限制并为芯片级精密计量开辟新途径。
英文摘要
Optical frequency combs form phase-locked spectral lines arranged on an equidistant grid fully defined by two degrees of freedom, i.e., the repetition rate and frequency offset. Stabilizing these parameters to a common frequency reference results in a coherent frequency ruler, central for modern precision metrology. However, extending this level of stability to chip-scale microcombs remains an outstanding challenge. Here, we demonstrate a self-stabilizing mechanism based on self-injection locking of a selected comb line via an external feedback loop. This process establishes a second anchor point in addition to the pump, thereby constraining the comb's frequency noise dynamics. We show that, with an appropriate choice between pump frequency noise and feedback strength, collective fluctuations of the repetition rate are strongly suppressed. The result is a microcomb exhibiting ultralow phase noise and dramatically reduced timing jitter. In a 100 GHz silicon nitride soliton microcomb, we achieve an unprecedented combination of high-conversion efficiency, sub-Hertz intrinsic linewidth across the entire C band, and an integrated timing jitter of 1 fs. This approach enables chip-scale microcombs with remarkable noise performance and fs-level pulse stability, surpassing conventional noise limits and opening new avenues for precision metrology at the chip scale.
