A method that obtains the Ramsey-coherent population trapping （CPT） spectrum with the Faraday effect is investi- gated. An experiment is implemented to detect the light polarization components generated from the Far...A method that obtains the Ramsey-coherent population trapping （CPT） spectrum with the Faraday effect is investi- gated. An experiment is implemented to detect the light polarization components generated from the Faraday effect. The experimental results agree with the theoretical calculations based on the Liouville equation. By comparing with the method without using the Faraday effect, the potential of this method for a CPT-based atomic clock is assessed. The results indicate that this method should improve the short-term frequency stability by several times.展开更多
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...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。展开更多
基于相干布局囚禁(Coherent Population Trapping)的被动型气泡原子钟,因其优良的短稳2E-13@1s和中期稳定度2.5E-15@10^4s,而成为高性能原子钟的有力竞争者。本文基于一种新构型来探索实现高性能小型化CPT原子钟。我们通过3.4GHz微波直...基于相干布局囚禁(Coherent Population Trapping)的被动型气泡原子钟,因其优良的短稳2E-13@1s和中期稳定度2.5E-15@10^4s,而成为高性能原子钟的有力竞争者。本文基于一种新构型来探索实现高性能小型化CPT原子钟。我们通过3.4GHz微波直接调制分布式布拉格反射(DBR)激光器产生相干双色光,同时在微波和激光光束上分别施加同步的相位调制和偏振调制,实现相干极化调制,获得了较高对比度(14.7%)和较窄线宽(416Hz)的CPT共振信号。该方案采用直接调制技术使原子钟系统体积、复杂性和环境敏感性都得到减小,这使得高性能CPT原子钟的小型化成为可能。展开更多
本文提出了一种降低相干布居囚禁CPT(coherent population trapping)原子钟噪声,提高短期稳定度的方法。在我们的实验装置中,经过AOM而产生的两束光通过同一个原子气室。一束圆偏振光用于产生CPT,另一束线偏振光只发生共振吸收,两者差...本文提出了一种降低相干布居囚禁CPT(coherent population trapping)原子钟噪声,提高短期稳定度的方法。在我们的实验装置中,经过AOM而产生的两束光通过同一个原子气室。一束圆偏振光用于产生CPT,另一束线偏振光只发生共振吸收,两者差分就可以消除共模噪声。通过AOM射频开关的打开和关闭,可以完成传统CPT原子钟和差分检测方案之间的转换,便于进行对照实验。实验结果表明,差分检测方案将原子钟的百秒稳定度提高了1.4倍。展开更多
A Cs vapor cell-based atomic clock that uses a lin‖lin pumping scheme with dispersion detection is reported. This atomic clock shows potential for high performance because of its high contrast pumping scheme, and for...A Cs vapor cell-based atomic clock that uses a lin‖lin pumping scheme with dispersion detection is reported. This atomic clock shows potential for high performance because of its high contrast pumping scheme, and for miniaturization because of its simple architecture. The experimental setup and optimal operating parameters for the clock are introduced.The current fractional frequency stability is measured to be 1.3 × 10^-12/■ up to 20s and reaches 3.1 × 10^-13 at 200 s. We have thoroughly investigated the related noise sources that affect clock frequency stability at the 1s and 100s levels. The investigation shows that the laser frequency noise limits the clock frequency stability significantly. The clock performance can be further improved by technically upgrading the laser frequency stabilization setup.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11304362 and 11204351)
文摘A method that obtains the Ramsey-coherent population trapping （CPT） spectrum with the Faraday effect is investi- gated. An experiment is implemented to detect the light polarization components generated from the Faraday effect. The experimental results agree with the theoretical calculations based on the Liouville equation. By comparing with the method without using the Faraday effect, the potential of this method for a CPT-based atomic clock is assessed. The results indicate that this method should improve the short-term frequency stability by several times.
文摘简要介绍了新型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。
文摘基于相干布局囚禁(Coherent Population Trapping)的被动型气泡原子钟,因其优良的短稳2E-13@1s和中期稳定度2.5E-15@10^4s,而成为高性能原子钟的有力竞争者。本文基于一种新构型来探索实现高性能小型化CPT原子钟。我们通过3.4GHz微波直接调制分布式布拉格反射(DBR)激光器产生相干双色光,同时在微波和激光光束上分别施加同步的相位调制和偏振调制,实现相干极化调制,获得了较高对比度(14.7%)和较窄线宽(416Hz)的CPT共振信号。该方案采用直接调制技术使原子钟系统体积、复杂性和环境敏感性都得到减小,这使得高性能CPT原子钟的小型化成为可能。
文摘本文提出了一种降低相干布居囚禁CPT(coherent population trapping)原子钟噪声,提高短期稳定度的方法。在我们的实验装置中,经过AOM而产生的两束光通过同一个原子气室。一束圆偏振光用于产生CPT,另一束线偏振光只发生共振吸收,两者差分就可以消除共模噪声。通过AOM射频开关的打开和关闭,可以完成传统CPT原子钟和差分检测方案之间的转换,便于进行对照实验。实验结果表明,差分检测方案将原子钟的百秒稳定度提高了1.4倍。
基金Project supported by the National Key Research and Development Progress of China(Grant No.2016YFA030210)the Initiative Program of the State Key Laboratory of Precision Measurement Technology and Instruments,China
文摘A Cs vapor cell-based atomic clock that uses a lin‖lin pumping scheme with dispersion detection is reported. This atomic clock shows potential for high performance because of its high contrast pumping scheme, and for miniaturization because of its simple architecture. The experimental setup and optimal operating parameters for the clock are introduced.The current fractional frequency stability is measured to be 1.3 × 10^-12/■ up to 20s and reaches 3.1 × 10^-13 at 200 s. We have thoroughly investigated the related noise sources that affect clock frequency stability at the 1s and 100s levels. The investigation shows that the laser frequency noise limits the clock frequency stability significantly. The clock performance can be further improved by technically upgrading the laser frequency stabilization setup.
