The frequency stability of many optical atomic clocks is limited by the coherence of their local oscillator. Here, we present a measurement protocol that overcomes the laser coherence limit. It relies on engineered dynamical decoupling of laser phase noise and near-synchronous interrogation of two clocks. One clock coarsely tracks the laser phase using dynamical decoupling; the other refines this estimate using a high-resolution phase measurement. While the former needs to have a high signal-to-noise ratio, the latter clock may operate with any number of particles. The protocol effectively enables minute-long Ramsey interrogation for coherence times of few seconds as provided by the current best ultrastable laser systems. We demonstrate implementation of the protocol in a realistic proof-of-principle experiment, where we interrogate for 0.5 s at a laser coherence time of 77 ms. Here, a single lattice clock is used to emulate synchronous interrogation of two separate clocks in the presence of artificial laser frequency noise. We discuss the frequency instability of a single-ion clock that would result from using the protocol for stabilisation, under these conditions and for minute-long interrogation, and find expected instabilities of σ_y(τ) = 8 × 10⁻¹⁶(τ/s)^−1/2 and σ_y(τ) = 5 × 10⁻¹⁷(τ/s)^−1/2, respectively.

许多光学原子钟的频率稳定性受其本地振荡器的相干性限制。在这里，我们提出了一种克服了激光相干极限的测量方案。它依赖于激光相位噪声的工程动态去耦和两个时钟的近同步询问。一个时钟通过动态去耦来粗略地跟踪激光相位。另一个使用高分辨率相位测量来完善此估计。前者需要具有较高的信噪比，而后者的时钟可以使用任何数量的粒子运行。该协议有效地实现了由目前最好的超稳定激光系统提供的长达数秒的相干时间长达一分钟的Ramsey询问。我们在现实的原理证明实验中演示了该协议的实现，其中我们询问0。在77 ms的激光相干时间下5 s。在此，在存在人工激光频率噪声的情况下，单个晶格时钟用于模拟两个单独时钟的同步询问。我们讨论了在这种情况下以及长时间的询问下，使用该协议进行稳定操作会导致单离子时钟的频率不稳定性，并发现了预期的不稳定性。σ _ÿ（τ）= 8×10 ^-16（τ / ^S）-1/2和σ _ÿ（τ）= 5×10 ^-17（τ /秒^{） -1/2}分别。