We analyze an optical atomic clock using two-photon 5S1/2→4DJ transitions in rubidium. Four one- and two-color excitation schemes to probe the 4D3/2 and 4D5/2 fine-structure states are considered in detail. We compare key characteristics of Rb 4DJ and 5D5/2 two-photon clocks. The 4DJ clock features a high signal-to-noise ratio due to two-photon decay at favorable wavelengths, low dc electric and magnetic susceptibilities, and minimal black-body shifts. Ac Stark shifts from the clock interrogation lasers are compensated by two-color Rabi-frequency matching. We identify a ‘magic’ wavelength near 1060 nm, which allows for in-trap, Doppler-free clock-transition interrogation with lattice-trapped cold atoms. From our analysis of clock statistics and systematics, we project a quantum-noise-limited relative clock stability at the 10−13/τ(s)-level, with integration time τ in seconds, and a relative accuracy of ∼10−13. We describe a potential architecture for implementing the proposed clock using a single telecom clock laser at 1550 nm, which is conducive to optical communication and long-distance clock comparisons. Our work could be of interest in efforts to realize small and portable Rb clocks and in high-precision measurements of atomic properties of Rb 4DJ-states.

中文翻译：

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使用铷 4DJ 态的光学原子钟


我们使用铷中的双光子 5S1/2→4DJ 跃迁分析光学原子钟。详细考虑了探测 4D3/2 和 4D5/2 精细结构态的四种一色和双色激发方案。我们比较了 Rb 4DJ 和 5D5/2 双光子时钟的关键特性。由于有利波长下的双光子衰减，4DJ 时钟具有高信噪比、低直流电和磁化率以及最小的黑体位移。时钟询问激光器的 Ac Stark 偏移通过双色拉比频率匹配进行补偿。我们确定了 1060 nm 附近的“神奇”波长，它允许使用晶格捕获的冷原子进行捕获内、无多普勒时钟跃迁询问。根据我们对时钟统计和系统学的分析，我们预测量子噪声限制的相对时钟稳定性在 10−13/τ(s) 级别，积分时间 τ 以秒为单位，相对精度为 ∼10−13。我们描述了一种使用 1550 nm 的单个电信时钟激光器来实现所提出的时钟的潜在架构，这有利于光通信和长距离时钟比较。我们的工作可能涉及实现小型便携式铷时钟以及铷 4DJ 态原子特性的高精度测量。