In a series of three papers published in 2024[1-3],physicists in Austria,Germany,and the United States reported the first direct observations with table-top lasers of a new nuclear process,in which the nucleus of a th...In a series of three papers published in 2024[1-3],physicists in Austria,Germany,and the United States reported the first direct observations with table-top lasers of a new nuclear process,in which the nucleus of a thorium atom absorbs a photon and goes into an excited state,then re-emits the photon and returns to its ground state.This“thorescence”phenomenon“is exactly the same process as fluorescence,but it takes place inside the nucleus,”said Ekkehard Peik,professor and head of the department of time and frequency at the Physikalisch-Technische Bundesanstalt(the German national metrology institute)in Braunschweig,Germany.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
文摘In a series of three papers published in 2024[1-3],physicists in Austria,Germany,and the United States reported the first direct observations with table-top lasers of a new nuclear process,in which the nucleus of a thorium atom absorbs a photon and goes into an excited state,then re-emits the photon and returns to its ground state.This“thorescence”phenomenon“is exactly the same process as fluorescence,but it takes place inside the nucleus,”said Ekkehard Peik,professor and head of the department of time and frequency at the Physikalisch-Technische Bundesanstalt(the German national metrology institute)in Braunschweig,Germany.
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。
