Trapped ion clock with enhanced reliability (TICKER)

具有增强可靠性的俘获离子钟 (TICKER)

• 批准号: EP/Y005112/1
• 负责人: Patrick Gill
• 金额: $ 103.26万
• 依托单位: National Physical Laboratory
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FY005112%2F1
• 关键词: Trapped; ion; clock; enhanced; reliability

The 'trapped ion clock with enhanced reliability' project (TICKER) brings together world leading expertise in metrological-grade ion trap development, ultrastable room-temperature cavity-stabilised lasers, and laser source development to deliver unprecedented performance in a field-deployed state-of-the-art optical clock.Optical atomic clocks (OACs) have made extraordinary improvements over the last few decades and represent the pinnacle of precision measurement technology. The extreme accuracy of OACs enables exciting new opportunities for both fundamental physics and technology from detecting dark matter, relativistic geodesy, and improving satellite navigation accuracy. However, the science and technology impact from the current generation optical atomic clocks has been limited for the wider technology and industry base as they are fragile and complex laboratory-sized systems operated in well-controlled environments by skilled scientists. These limitations mean that only a handful of operational examples exist worldwide, restricted to National Metrology Institutes (NMIs) such as NPL. To unlock the transformative potential from OACs they must become simpler and more robust. This cannot be achieved by simply shrinking a laboratory clock; new approaches and technologies are called for.We will develop the technologies that bypass these constraints and allow the creation of practical optical clocks, focusing on the singly ionised strontium-88 (Sr+) system as the most viable candidate. Within this project we will develop metrological-grade ion traps that are manufacturable and robust enough to operate in less-well-controlled remote locations and mobile platforms, a transportable environmentally insensitive optical reference cavity, and a 422-nm DFB laser as a low-power and robust source for laser-cooling the ion. Atomic clocks based on trapped ions are inherently simpler and require lower power to operate than the other major class of high-performance clocks - neutral atom lattice clocks. Ion clocks also have relaxed requirements of the clock-laser, making them more suitable for noisy environments. Trapping and laser cooling a single ion requires less than a watt of RF power and less than a milliwatt of optical power; the electrode structure and vacuum system can be miniaturised and ruggedised using established techniques aided by finite element analysis. The Sr+ system is particularly attractive because the clock transition can be measured in a way that provides low sensitivity of the centre frequency to the environment. Additionally, the transitions in its simple energy level structure can mostly be addressed with commodity lasers. One exception is the 422-nm laser-cooling transition. Currently this light must be produced from either a vibration sensitive ECDL laser or inefficient frequency doubling from an infrared DFB laser. A 422-nm DFB laser would enable a great improvement in the SWAP and robustness.NPL's patented cubic cavity design is the leading transportable and force insensitive design and will be adapted to suit the requirements of field-deployable atomic clocks. Reducing the volume of the cubic cavity spacer from 125 cc to 27 cc still provides good frequency stability while greatly reducing the required environmental shielding. Moreover, we have invented a novel technique that exploits material anisotropy to further reduce environmental impact, which will extend the temperature-insensitivity alongside the force- and vibration-insensitive design. Together, with the addition of an optical frequency comb (being developed at pace under many other programs, to the requirements of optical clocks) we address the major challenges that are preventing optical clocks from field deployed applications.

“增强可靠性的捕获离子钟”项目（TICKER）汇集了计量级离子阱开发、超稳定室温腔稳定激光器、和激光源的开发，为现场部署的最先进的光学时钟提供前所未有的性能。光学原子钟（OAC）在过去的几十年里取得了非凡的进步，代表了精密测量技术的顶峰。OAC的极高精度为基础物理和技术提供了令人兴奋的新机会，包括探测暗物质，相对论大地测量和提高卫星导航精度。然而，当前一代光学原子钟的科学和技术影响对于更广泛的技术和工业基础来说是有限的，因为它们是由熟练的科学家在良好控制的环境中操作的脆弱而复杂的实验室大小的系统。这些局限性意味着全世界只有少数几个可操作的例子，仅限于国家计量研究所（NMI），如NPL。为了释放OAC的变革潜力，它们必须变得更简单、更强大。这不能通过简单地缩小实验室时钟来实现;需要新的方法和技术。我们将开发绕过这些限制的技术，并允许创建实用的光学时钟，专注于单电离锶-88（Sr+）系统作为最可行的候选者。在这个项目中，我们将开发计量级离子阱，这些离子阱是可制造的，并且足够坚固，可以在控制不太好的远程位置和移动的平台上运行，一个可运输的环境不敏感的光学参考腔，以及一个422 nm DFB激光器作为激光冷却离子的低功率和坚固的源。基于俘获离子的原子钟本质上比其他主要类别的高性能时钟-中性原子晶格时钟更简单，需要更低的功率来运行。离子钟也放宽了对时钟激光器的要求，使它们更适合嘈杂的环境。捕获和激光冷却单个离子需要小于1瓦的射频功率和小于1毫瓦的光功率;电极结构和真空系统可以使用有限元分析辅助的现有技术进行简化和加固。Sr+系统是特别有吸引力的，因为可以以提供中心频率对环境的低灵敏度的方式测量时钟跳变。此外，其简单能级结构的转变大多可以用商品激光器来解决。一个例外是422 nm激光冷却过渡。目前，这种光必须由振动敏感的ECDL激光器或红外DFB激光器的低效倍频产生。422 nm DFB激光器将大大提高SWAP和鲁棒性。NPL的专利立方腔设计是领先的可移动和力不敏感设计，将适应现场部署原子钟的要求。将立方腔间隔件的体积从125 cc减小到27 cc仍然提供良好的频率稳定性，同时大大减小所需的环境屏蔽。此外，我们还发明了一种新技术，利用材料的各向异性进一步减少对环境的影响，这将扩展温度不敏感性以及力和振动不敏感设计。与此同时，增加了光频梳（正在开发的步伐下，许多其他计划，光学时钟的要求），我们解决了主要的挑战，阻止光学时钟从现场部署的应用。

项目成果

An ion trap design for a space-deployable strontium-ion optical clock

空间部署锶离子光学钟的离子阱设计

• DOI: 10.1098/rspa.2023.0593
• 发表时间: 2024
• 期刊: Mathematical, Physical and Engineering Sciences
• 作者: Spampinato A

Towards space-deployable laser stabilization systems based on vibration-insensitive cubic cavities with crystalline coatings.

基于具有结晶涂层的振动不敏感立方腔的空间可部署激光稳定系统。

• DOI: 10.1364/oe.506833
• 发表时间: 2024
• 期刊: Optics express
• 影响因子: 3.8
• 作者: Cole GD