The absolute frequency of the 87Sr optical clock transition
arXiv:0804.4509 · doi:10.1088/0026-1394/45/5/008
Abstract
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.
References in corpus (11)
- Sr lattice clock at 1x10^{-16} fractional uncertainty by remote optical evaluation with a Ca clock
- Quantum State Engineering and Precision Metrology using State-Insensitive Light Traps
- Compact, thermal-noise-limited optical cavity for diode laser stabilization at 1 x 10-15
- New Limits on Coupling of Fundamental Constants to Gravity Using Sr Optical Lattice Clocks
- Nuclear Spin Effects in Optical Lattice Clocks
- Sr lattice clock with inaccuracy below 10
- Optical Lattice Induced Light Shifts in an Yb Atomic Clock
- Optical atomic coherence at the one-second time scale
- Coherent optical phase transfer over a 32-km fiber with 1-s instability at
- Improved frequency measurement of a one-dimensional optical lattice clock with a spin-polarized fermionic Sr isotope
- An Optical Lattice Clock with Spin-polarized 87Sr Atoms