A 920-Kilometer Optical Fiber Link for Frequency Metrology at the 19th Decimal Place
A 920-Kilometer Optical Fiber Link for Frequency Metrology at the 19th Decimal Place
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DOI：
10.1126/science.1218442
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发表时间：
2012-04-27
期刊：
影响因子：
56.9
通讯作者：
Schnatz, H.
中科院分区：
文献类型：
--
作者：
Predehl, K.;Grosche, G.;Schnatz, H.
光学时钟显示出前所未有的精度，比以前可用的时钟系统高出一个数量级以上。精确的相互比较将使各种实验成为可能，包括对基本量子物理学和宇宙学的测试以及在大地测量学和导航中的应用。成熟的基于卫星的微波传播技术不足以比较光学时钟。在这里，我们提出了超过920公里的电信光纤的光频率的相位稳定分布。我们使用两个反平行光纤链路来确定它们的分数频率不稳定性（修正Allan偏差）在1秒的积分时间内达到5 x 10(-15)，在不到1000秒的时间内达到10（-18）。对于长积分时间tau，与预期频率值的偏差被限制在4 x 10（-19）内。该链路可以作为全欧洲光频率传播网络的一部分。
Optical clocks show unprecedented accuracy, surpassing that of previously available clock systems by more than one order of magnitude. Precise intercomparisons will enable a variety of experiments, including tests of fundamental quantum physics and cosmology and applications in geodesy and navigation. Well-established, satellite-based techniques for microwave dissemination are not adequate to compare optical clocks. Here, we present phase-stabilized distribution of an optical frequency over 920 kilometers of telecommunication fiber. We used two antiparallel fiber links to determine their fractional frequency instability (modified Allan deviation) to 5 x 10(-15) in a 1-second integration time, reaching 10(-18) in less than 1000 seconds. For long integration times tau, the deviation from the expected frequency value has been constrained to within 4 x 10(-19). The link may serve as part of a Europe-wide optical frequency dissemination network.