从CPT原子钟到光钟

FROM CPT CLOCK TO OPTICAL CLOCK

简要介绍了新型CPT(Coherent population trapping,相干布局囚禁)原子频标及光频标的基本原理和研究进展。被动型CPT铷原子钟物理部分的目前体积可控制在100cm^3以内,功耗1W左右,其稳定度为4×10^(-11)τ^(-1/2)(τ为测量取样的时间间隔)。CPT原理的铯原子频标的物理部分体积减小到1cm^3,功率减小到30mW,稳定度为6×10^(-10)τ^(-1/2),成为当今体积最小、功耗最低的原子钟。随着飞秒激光梳状发生器技术的发展,已将传统的谐波光频链的体积从几间实验室缩小到1.2×1.0m^2的光学平台上,它与光频测量技术的结合,使微波频标与光频标联系起来,建立了光钟,它的稳定性可以从现在的10^(-116)的水平提高到10^(-18)乃至10^(-22)水平,成为当前最精密的时间计量仪器。

This paper describes the basic principle and the research progresses of the CPT （Coherent Population Trapping） atomic frequency standard and the light frequency standard. The physics package of Rb maser （CPT, passive） can be controlled in the 100 cm^3, lower 1 W consumptions and the stability is 4 × 10^-11τ^-1/2 . To Cs maser, CPT, the physics package is only about 1 cm^3, the consumption is lower 30 mW, the stability is better than 6 ×10^-10τ^-1/2 . It is the minimum atomic clock with lowest consumption in the world currently. As the development of technology, the comb generator of femto - second laser combs has been integrated on the optics stage of 1.2 × 1.0 m^2. Since combining the femto-second laser combs with optics measure method, the light clock is set up. Its stability can raise 10^-16 to 10^-18 or 10^-22, it will become the most precise time instrument at present.