A 920-Kilometer Optical Fiber Link for Frequency Metrology at the 19th Decimal Place

作者：Predehl, K.^*; Grosche, G.; Raupach, S. M. F.; Droste, S.; Terra, O.; Alnis, J.; Legero, Th.; Haensch, T. W.; Udem, Th.; Holzwarth, R.; Schnatz, H.

来源：Science, 2012, 336(6080): 441-444.

DOI：10.1126/science.1218442

• COHERENT TRANSFER
• RESOLUTION
• NETWORK
• CLOCKS

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.

• 出版日期2012-4-27