The NIM Sr Optical Lattice Clock

8th Symposium on Frequency Standards and Metrology 2015

Lin, Y.^1 ; Wang, Q.^1,2 ; Li, Y.^1,2 ; Meng, F.^1,3 ; Lin, B.^1,2 ; Zang, E.^1 ; Sun, Z.^1 ; Fang, F.^1 ; Li, T.^1 ; Fang, Z.^1

Division of Time and Frequency, National Institute of Metrology, Beijing

100029, China^1

Department of Precision Instrument, Tsinghua University, Beijing

100084, China^2

School of Electronics Engineering and Computer Science, Peking University, Beijing

100871, China^3

关键词: Absolute frequency;    Cesium fountain;    Clock transition;    Excitation rate;    Frequency errors;    Narrow-line width;    Optical lattice clocks;    Systematic uncertainties;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/723/1/012021/pdf
DOI  :  10.1088/1742-6596/723/1/012021

来源: IOP

【 摘 要 】

A87Sr optical lattice clock is built at the National Institute of Metrology (NIM) of China. The atoms undergo two stages of laser cooling before being loaded into a horizontal optical lattice at the magic wavelength of 813 nm. After being interrogated by a narrow linewidth 698 nm clock laser pulse, the normalized excitation rate is measured to get the frequency error, which is then used to lock the clock laser to the ultra-narrow1S0-3P0clock transition. The total systematic uncertainty of the clock is evaluated to be 2.3 × 10-16, and the absolute frequency of the clock is measured to be 429 228 004 229 873.7(1.4) Hz with reference to the NIM5 cesium fountain.