2008/04/29 by Gretchen K. Campbell, Andrew D. Ludlow, Sebastian Blatt +13
Decision Sciences · Physics and Astronomy · #Advanced Fiber Laser Technologies #Advanced Frequency and Time Standards #Atomic physics #Nuclear physics #Physics #Scientific Measurement and Uncertainty Evaluation #physics.atom-ph
paper · pdf · doi:10.1088/0026-1394/45/5/008
published as Metrologia 45, 539-548 (2008).
arxiv created 2008/04/29 · openalex publication_date 2008/09/24 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The absolute frequency of the 1S0-3P0 clock transition of 87Sr has been measured to be 429 228 004 229 873.65 (37) Hz using lattice-confined atoms, where the fractional uncertainty of 8.6x10-16 represents one of the most accurate measurements of an atomic transition frequency to date. After a detailed study of systematic effects, which reduced the total systematic uncertainty of the Sr lattice clock to 1.5x10-16, the clock frequency is measured against a hydrogen maser which is simultaneously calibrated to the US primary frequency standard, the NIST Cs fountain clock, NIST-F1. The comparison is made possible using a femtosecond laser based optical frequency comb to phase coherently connect the optical and microwave spectral regions and by a 3.5 km fiber transfer scheme to compare the remotely located clock signals.