Demonstration of the Systematic Evaluation of an Optical Lattice Clock Using the Drift-Insensitive Self-Comparison Method

Applied Sciences

Yebing Wang¹  Xiaotong Lu¹  Hong Chang¹  Chihua Zhou¹  Benquan Lu¹ 

[1] Key Laboratory of Time and Frequency Primary Standards, National Time Service Center, Chinese Academy of Sciences, Xi’an 710600, China;

关键词: optical lattice clocks;    strontium atoms;    optical lattices;    laser cooling and trapping;   

DOI  :  10.3390/app11031206

来源: DOAJ

【 摘 要 】

The self-comparison method is a powerful tool in the uncertainty evaluation of optical lattice clocks, but any drifts will cause a frequency offset between the two compared clock loops and thus lead to incorrect measurement result. We propose a drift-insensitive self-comparison method to remove this frequency offset by adjusting the clock detection sequence. We also experimentally demonstrate the validity of this method in a one-dimensional ⁸⁷Sr optical lattice clock. As the clock laser frequency drift exists, the measured frequency difference between two identical clock loops is (240 ± 34) mHz using the traditional self-comparison method, while it is (−15 ± 16) mHz using the drift-insensitive self-comparison method, indicating that this frequency offset is cancelled within current measurement precision. We further use the drift-insensitive self-comparison technique to measure the collisional shift and the second-order Zeeman shift of our clock and the results show that the fractional collisional shift and the second-order Zeeman shift are 4.54(28) × 10⁻¹⁶ and 5.06(3) × 10⁻¹⁷, respectively.

【 授权许可】

Unknown