[论文解读] Self-aligned optical microcomb emerging between octave separated lasers

Grégory Moille, Pradyoth Shandilya+12 more|arXiv (Cornell University)|Feb 5, 2026

Advanced Fiber Laser Technologies被引用 0

一句话总结

论文展示了一种在芯片尺度 χ(3) 共振腔中通过两路跨两个八度的泵浦产生的自对准参数耗散腔子谱（PDCS）微梳，能够产生一个八度跨越、单一频率网格的光频梳，具备固有的 CEO 自稳定性，并已在光学综合、毫米波生成和光时钟读出方面得到演示。

ABSTRACT

Optical frequency combs (OFCs) are frequency rulers essential for precision metrology, next generation navigation, and testing of fundamental physics. Despite intense efforts, chip-integrated OFCs remain laboratory-bound, unable to fulfill their promise of compact and cost-effective deployment. While improvement in fabrication and integration are important, a conceptual limitation has fundamentally stymied progress: on-chip OFC architectures have aimed to miniaturize their table-top counterparts and relied on cascading outward from (i.e., spectrally broadening) a single pump. In integrated platforms, this approach does not readily allow for the generation of strong and low-noise octave-spaced signals that are crucially needed for robust zero-frequency offset detection. Here, we overcome this limitation via an architectural inversion where an optical microcomb forms by filling the spectrum between two octave-separated pump lasers. The two pumps generate a parametrically driven cavity soliton (PDCS) in an integrated $χ^{(3)}$ resonator, which robustly self-aligns to (i.e., synchronizes with) the pump lasers across multiple foundry-fabricated devices and operating configurations. This produces a single octave-spanning comb extending from telecom to visible wavelengths, whose zero-frequency offset is completely defined by the two harmonically-related pump lasers, and can therefore be reliably detected and stabilized. We showcase our platform's capabilities by executing all of the three core tasks of OFC metrology: optical frequency synthesis, low-noise millimeter-wave generation, and integrated optical clock readout, using the same self-aligned microcomb with only its input locks changed.

研究动机与目标

• 解决传统芯片 OFC 由单一泵驱动而级联、难以实现稳健的八度跨越信号的局限性。
• 引入并演示一种双泵 PDCS 架构，使其能够自对准于泵浦，形成单一八度跨越的频率网格。
• 在光学频率综合、低噪声毫米波生成、集成光学时钟读出三大 OFC 计量任务中展示 PDCS 平台。

提出的方法

• 在 ν− 和 ν+ 的两路 CW 泵驱动下，利用两倍频近似为 2 ν− 的 χ(3) 硅氮微环共振腔生成 PDCS。
• 设计共振腔色散，使在跨越八度的泵浦间实现简并的 OPO 和 PDCS 自对准条件。
• 利用 Kerr 非线性将 PDCS 与泵梳锁定在相同的重复率，同时实现自对准（Δν_ceo → 0）。
• 将重复率定义为 ν_rep^(pdcs) = (ν+ − ν−)/N，其中 N = n+ − n−，从泵浦间距实现确定性 OFD。
• 在芯片前实现 CEO 控制，通过将 νceo^(pdcs) 与 ν+ 与 2ν− 的拍频相关联，允许在梳子产生前实现灵活的锁定架构。
• demonstrate waferscale Si3N4 微环在双泵 PDCS 下产生一个覆盖从通信波段到可见光的八度跨越、无缝隙谱。

Figure 1: Concept of self-aligned parametrically driven cavity soliton (PDCS) microcomb generation with octave-separated lasers — a, Schematic of dual-pump PDCS generation. Two pump lasers (with frequencies $\nu_{-}$ and $\nu_{+}\approx 2\nu_{-}$ ) are injected into a $\chi^{(3)}$ microring resonato

实验结果

研究问题

• RQ1 在 χ(3) 微共振腔中，是否可以用两路跨八度的泵产生 PDCS？
• RQ2 Kerr 引起的同步是否会自对准 PDCS 与两个泵，产生单一、八度跨越的频率网格？
• RQ3 自对准的 PDCS 是否能够提供稳定的 CEO 和重复率锁定，适用于光学频率综合、毫米波生成和时钟工作？
• RQ4 自对准机制在不同器件几何和泵配置下的鲁棒性如何？
• RQ5 与传统单泵微梳相比，自对准 PDCS 能提供哪些计量学优势？

主要发现

• 实现了具有两路跨八度泵的八度跨越 PDCS 微梳，在泵之间形成单一频率网格。
• PDCS 与泵梳之间的 Δν_ceo 在有限的泵浦范围内消失，表明 Kerr 引起的自对准到泵。
• PDCS 的重复率由泵浦间距确定性设定，且可表示为 ν_rep^(pdcs) = (ν+ − ν−)/N，便于光学到微波的分频。
• 同步化使重复率噪声低于非同步的 PDCS，指示微波到光学链路更具相干性。
• 同一自对准 PDCS 平台通过改变输入锁定配置即可执行光学频率综合、低噪声毫米波生成和光学时钟读出。
• 光学时钟工作演示在以原子跃迁为基准时显示出与参考系统相当的长时稳定性，验证了该方法在时钟应用中的可行性。

Figure 2: Demonstration of self-aligned octave-spanning PDCS microcomb — a, Dispersion engineering for dual-pump PDCS generation ( $RW=850\text{\penalty 10000\ }$ ). OPO frequency mismatch $\Delta\nu$ (circles: measured, solid line: simulation) when pumped at $n_{-}=263$ ( $\nu_{-}=193.55\text{\pena