NIM的微波-光学频率基准研究——复现米和秒定义

Microwave-Optical Frequency Standards at NIM:Realizing of Definition of Metre and Second

报道中国计量科学研究院(NIM)在微波-光学频率计量研究的新进展:用NIM4激光冷却-铯原子喷泉钟复现国际单位制(SI)时间单位秒(s),用飞秒(FS)光学频率梳间接复现长度单位米(m)并标定稳频激光波长实际实施米定义。NIM4铯原子喷泉钟的不确定度达到5×10-15,飞秒(FS)光梳锁定到NIM4钟控制的氢钟后,其频率不确定度为2·2×10-14。在此基础上讨论铯原子喷泉钟、稳频激光、FS光梳的作用、意义和相互关系。最后简要介绍NIM5铯原子喷泉钟的研究进展和2006年起NIM立题研制锶原子存储光钟。

The paper presents the realization, at NIM, of SI time unit second using the NIM4 cesium fountain clock, SI length unit meter using a femto-second （FS） optical frequency comb and calibration of wavelengths of stabilized lasers by this FS comb. The uncertainty of NIM4 fountain clock was evaluated as 5 × 10^15. The frequency uncertainty of the FS optical comb locked to a H-maser, which is steered by NIM4 clock, was estimated as 2.2 × 10^- 14 The function, significance of Cs fountain clock, stabilized lasers, optical comb and relationship among them are discussed. Finally the progress of NIM5 fountain clock and the construction of a Sr atom optical clock started in 2006 at NIM are reported.