摘要
报道了中国计量科学研究院(NIM)在复现国际单位制(SI)长度单位米和时间单位秒的研究进展,包括稳频激光、NIM4铯原子喷泉钟和飞秒光学频率梳。NIM4钟不确定度达4.4×10-15,NIM在研的飞秒光梳将以优于1×10-13的不确定度实现光学波长向微波频率的溯源。文中还讨论了127I2饱和吸收6 3 3 nm 3次谐波稳频的He-Ne激光波长比5次谐波稳频的更“准确”;指出飞秒光梳是从动跟踪系统,描述它的性能指标应当是它的跟踪精度;估计了用“吸收室—原子束—原子喷泉—原子/离子存储”4种不同原理所建频标可能达到的不确定度极限。最后简略展望时间频率基准研究的新动向———光钟。
Progress on realization of SI length unit meter and time unit second at National Institute of Metrology （NIM） is presented, including stabilized lasers, NIM4 cesium fountain clock and femto-second optical frequency comb. The NIM4 clock has achieved an uncertainty of 4.4 ×10^15, the femto-second optical comb under development will bridge the gap between optical wavelength and microwave frequency with an uncertainty of better than 1 ×10^13. Also discussed： （1） the 633 nm wavelength stabilized with ^127I2 3rd harmonic is more accurate than with 5th harmonic; （2） femto-second optical comb is a serve-locking system and the specification to describe its performance should be its tracking precision; （3） the estimated uncertainty limitations of ＂sample cell-atomic beam-atomic fountain-trapped atom/ion＂ frequency reference techniques are given. Finally, the developing trend of time and frequency standard optical clock is briefly looked ahead.
出处
《计量学报》
EI
CSCD
北大核心
2006年第1期1-6,共6页
Acta Metrologica Sinica
基金
科技部基础专项基金(G99-B-14)
(2001-DEA-12)
关键词
计量学
频率标准
波长标准
铯原子喷泉钟
飞秒光梳
Metrology
Frequency standard
Wavelength standard
Cesium atomic fountain clock
Femto-second optical frequency comb
