International Clock and Oscillator Networking - ICON

时间是所有计量量中测量精度最高的量。在我们的日常生活中，我们都受益于这种非凡的精度，因为精确的时间可以使超高速宽带通信中的数据包同步，并通过计算卫星导航中射频信号的飞行时间来确定我们的位置，精确到纳秒。这些经济上重要的应用依赖于微波原子钟，其商业形式精确到10^14的1分之一。由于光学时钟的发明和计算光学频率的方法，我们目前正面临着计时精度的革命，这已经在2005年获得了诺贝尔物理学奖。这些新型时钟的稳定性已经超过了10^18的1分之一，比目前的技术水平高出了4个数量级。然而，虽然时钟技术正在迅速发展，但如何以实用有效的方式将这种精度转移到用户社区仍有很多需要学习的地方。微波链路，如目前使用的卫星时间传输，对于这样的精度来说是不切实际的慢，而光纤链路需要昂贵的专用光纤连接，并且限制在100公里以内，这使得洲际连接不切实际。此外，在10^-18的精度下，诸如将重力与频率耦合的广义相对论等效应开始发挥作用，并使转移依赖于大陆板块在地球潮汐和更大降雨中的变形。ICON将世界领先的可移动光学时钟和世界领先的光链路空间基础设施结合在一起，探索精确时间传递的极限。包括使用世界领先的原子芯片概念使可移动时钟更紧凑和坚固的工作，我们的目标是为每个人带来精确的时间-首先是依靠精密振荡器的研究人员，然后是商业应用，以造福更广泛的社会。

Time is the quantity, which can be measured to the highest precision of all metrological quantities. We all benefit from this extraordinary precision in our everyday lives, as precision time enables synchronization of data packets in ultrafast broadband communication and the determination of our position by computing the flight times of radiofrequency signals in Satellite Navigation to nanosecond precision. These economically important applications rely on microwave atomic clocks, which in their commercial form are precise to 1 part in 10^14. We are currently facing a revolution in timing accuracy due to the invention of optical clocks and accessible ways of counting optical frequencies, which has already been recognised by the Nobel Price in Physics in 2005. These novel clocks already reach stabilities beyond 1 part in 10^18, more than 4 orders of magnitude beyond the state-of-the art. However, while the clock technology is progressing rapidly, there is still a lot to learn about how such a precision can be transferred to the user community in a practical and efficient way. Microwave links, such as used in current satellite time transfers, are impractically slow for such precision, while optical fibre links need expensive dedicated fibre connections and are limited to a few 100 km, making intercontinental connections impractical. In addition, at 10^-18 precision, effects such as general relativity coupling gravity to frequency are coming into play and make the transfer dependent on deformation of the continental plates in Earth tides and larger rain falls. ICON brings together world leading transportable optical clocks and world leading optical link space infrastructure to explore the limits of precision time transfer. Including work on making transportable clocks more compact and robust with world-leading atom chip concepts, we are aiming at bringing precision time to everyone - first researchers relying on precision oscillators and later in commercial applications for the benefit of wider society.