发表机构
Adelaide University; Institute for Photonics, Advanced Sensing and Quantum Technologies (IPAS-QT); School of Physics, Chemistry and Earth Sciences; ARC Centre of Excellence in Optical Microcombs for Breakthrough Science (COMBS); Collaborative Research Hub for Alternative Positioning, Navigation and Timing (aPNT)（阿德莱德大学; 光子、先进传感与量子技术研究所; 物理、化学与地球科学学院; 突破科学光学微梳 ARC 卓越中心; 替代定位、导航和授时合作研究枢纽）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出一种基于铷双光子跃迁的便携式光学频率标准，结合商用电信技术与集成光频梳，实现高稳定性，推动光学原子钟走出实验室。
AI 中文摘要
便携式原子钟在众多应用中至关重要，尤其是在全球导航卫星系统的运行中。现有采用微波 interrogating 方案的便携式原子钟，如今在性能上常被基于光学 interrogating 的下一代原子频率标准所超越。尽管光学频率标准展现出大幅提升的频率稳定性，但它们直到最近才达到在精心维护的实验室环境之外展示这种改进性能所需的技术成熟度。在此，我们展示了一种完全自主且便携的光学频率标准，其基于$^{87}$Rb中$5S_{1/2}\ ightarrow5D_{5/2}$双光子跃迁的高效双色激发。该标准结合了稳健、高度成熟的商用现货电信技术与完全集成的便携式光学频率梳，提供与现有电子系统和基础设施对接至关重要的光学及微波输出。该系统在1秒积分时间内展现出$1.9\ imes10^{-13}$的分数频率稳定性，在8000秒积分时间内达到$3.5\ imes10^{-15}$，且无需漂移移除。这一便携式演示装置标志着Rb光学原子频率标准发展以及光学原子频率标准在实验室外部署方面的重要成就。
英文摘要
Portable atomic clocks are essential in a wide variety of applications, most notably in the operation of global navigation satellite systems. Existing portable atomic clocks utilizing microwave-based interrogation schemes are now routinely eclipsed by the next generation of atomic frequency standards based on optical interrogation. While optical frequency standards demonstrate greatly improved frequency stability, they have only recently reached a level of technical maturity required to demonstrate this improved performance outside of well curated laboratory environments. Here, we demonstrate a fully autonomous and portable optical frequency standard based on an efficient dual-color excitation of the $5S_{1/2}\rightarrow5D_{5/2}$ two-photon transition in $^{87}$Rb. The standard utilizes a combination of robust, highly developed commercial-off-the-shelf telecommunications technologies and a fully integrated portable optical frequency comb, providing the optical and microwave outputs vital for interfacing with existing electronic systems and infrastructure. The system demonstrates a fractional frequency stability of $1.9\times10^{-13}$ at 1s of integration time, reaching $3.5\times10^{-15}$ at 8000s of integration time without the need for drift removal. This portable demonstrator unit marks a significant achievement in the development of Rb optical atomic frequency standards, and for the deployment of optical atomic frequency standards outside of the laboratory.
