Preliminary Frequency Comparison of Two 40^Ca^＋ Optical Frequency Standards  

作　　者：刘培亮 黄垚 边武 邵虎 钱源 管桦 高克林 

机构地区：[1]State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 [2]Key Laboratory of Atomic Frequency Standards, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 [3]University of Chinese Academy of Sciences, Beijing 100049

出　　处：《Chinese Physics Letters》2014年第11期51-54,共4页中国物理快报（英文版）

基　　金：Supported by the National Basic Research Program of China under Grant Nos 2012CB821301, the National Natural Science Foundation of China under Grant Nos 91336211, 11034009, 11304363 and 11004222, and the Chinese Academy of Sciences.

摘　　要：Frequency comparison is one of the most efficient ways to evaluate the performance of a frequency standard. Based on the pre-existing 40^Ca＋ optical frequency standard, we set up the second 40^Ca^＋ optical frequency standard, which has been improved in the materials and structure of ion traps for better control of the magnetic field. After the compensation, the residual magnetic field at the position of the ion is adjusted to be～500nT with a long time jitter of～10nT, which is better than the pre-existing 40^Ca^＋ optical frequency standard. We realize the ＇4-point-closed-loop locking＇ on the second 40^Ca＋ optical frequency standard after a series of preparatory works. Through half an hour of measurement time, the two frequency standards exhibited a stability of 2.1 × 10^-13.τ^1/2 and a relative frequency difference of 1.5 （2.9）Hz.Frequency comparison is one of the most efficient ways to evaluate the performance of a frequency standard. Based on the pre-existing 40^Ca＋ optical frequency standard, we set up the second 40^Ca^＋ optical frequency standard, which has been improved in the materials and structure of ion traps for better control of the magnetic field. After the compensation, the residual magnetic field at the position of the ion is adjusted to be～500nT with a long time jitter of～10nT, which is better than the pre-existing 40^Ca^＋ optical frequency standard. We realize the ＇4-point-closed-loop locking＇ on the second 40^Ca＋ optical frequency standard after a series of preparatory works. Through half an hour of measurement time, the two frequency standards exhibited a stability of 2.1 × 10^-13.τ^1/2 and a relative frequency difference of 1.5 （2.9）Hz.

分 类 号：O43[机械工程—光学工程] TM935.11[理学—光学]