近日，美国麻省理工学院林肯实验室的Robert McConnell及其研究团队取得一项新进展。他们使用集成螺旋腔激光器实现了光学原子钟询问。相关研究成果已于2025年1月6日在国际知名学术期刊《自然—光子学》上发表。
该研究团队证实，当与1348纳米种子激光器对接时，集成式超高品质因数螺旋腔能够在芯片上实现7.5×10-14/√τ（τ为平均时间）。研究人员证明了由集成螺旋腔激光器探测的高性能光学原子钟，这为未来使用轻量级、便携式且可批量生产的，集成光学和电子元件构建先进时钟系统打开了大门。
据悉，光学原子钟在精密计时方面已展现出革命性的进步，但其能否在现实世界中得到广泛应用，关键在于这些时钟能否在实验室外运行。
光子集成技术为解决实现时钟便携性所需的微型化和加固化问题，提供了一个极具吸引力的方案，但同时也带来了一系列新挑战，即如何使用芯片级构建模块重现光学时钟的功能。用于原子询问的时钟激光器尤其是一个不确定因素，因为将精心设计的体腔稳定激光器的性能，转移到芯片上将异常困难。
附：英文原文
Title: Optical atomic clock interrogation using an integrated spiral cavity laser
Author: Loh, William, Reens, David, Kharas, Dave, Sumant, Alkesh, Belanger, Connor, Maxson, Ryan T., Medeiros, Alexander, Setzer, William, Gray, Dodd, DeBry, Kyle, Bruzewicz, Colin D., Plant, Jason, Liddell, John, West, Gavin N., Doshi, Sagar, Roychowdhury, Matthew, Kim, May E., Braje, Danielle, Juodawlkis, Paul W., Chiaverini, John, McConnell, Robert
Issue&Volume: 2025-01-06
Abstract: Optical atomic clocks have demonstrated revolutionary advances in precision timekeeping, but their applicability to the real world is critically dependent on whether such clocks can operate outside the laboratory. Photonic integration offers one compelling solution to address the miniaturization and ruggedization needed to enable clock portability, but brings with it a new set of challenges in recreating the functionality of an optical clock using chip-scale building blocks. The clock laser used for atom interrogation is one particular point of uncertainty, as the performance of the meticulously engineered bulk-cavity-stabilized lasers would be exceptionally difficult to transfer to chip. Here we demonstrate that an integrated ultrahigh-quality-factor spiral cavity, when interfaced with a 1,348nm seed laser, is able to reach a fractional frequency instability of 7.5×10-14 on chip. On frequency doubling the light to 674nm, we use this laser to interrogate the narrow-linewidth transition of 88Sr+ and showcase the operation of a Sr-ion clock with short-term instability averaging down as 3.9times 10-14/sqrt{tau } (τ, averaging time). Our demonstration of a high-performance optical atomic clock interrogated by an integrated spiral cavity laser opens the door for future advanced clock systems to be entirely constructed using lightweight, portable and mass-manufacturable integrated optics and electronics.
DOI: 10.1038/s41566-024-01588-8
Source: https://www.nature.com/articles/s41566-024-01588-8