We report a direct measurement of the $7s\ ^2S_{1/2}\rightarrow$ $7p\ ^2P_{3/2}$ electric dipole transition frequency in $^{226}$Ra$^{+}$. With a single laser-cooled radium ion we determine the transition frequency to be 785722.11(3) GHz by directly driving the transition with frequency-doubled light and measuring the frequency of the undoubled light with an iodine reference. This measurement addresses a discrepancy of five combined standard deviations between previously reported values.
Absolute frequency measurement of the $^2$S$_{1/2} \rightarrow ^2$F$_{7/2}$ optical clock transition in $^{171}$Yb$^+$ with an uncertainty of $4\times 10^{-16}$ using a frequency link to International Atomic Time
$^{171}$ Yb $^+$中的高度禁戒的$^2$ S $_{1/2} \rightarrow ^2$ F $_{7/2}$电八极跃迁是重新定义SI秒的潜在候选者。我们提出了一个测量的绝对频率的光学过渡，使用频率链接到国际原子时提供可追溯性SI秒。$^{171}$ Yb $^+$光频标工作时间为25天的76%，测得绝对频率为642 121 496 772 645.14（26）Hz。$4.0 \times 10 ^{-16}$的分数不确定度与以前报道的最佳测量结果相当，后者是通过与当地铯主频率标准进行直接比较而获得的。
The ytterbium atom is widely used in the fields of atomic physics, cavity quantum electrodynamics, quantum information processing and optical frequency standards. There is however a strong dispersion among the reported values of the ${}^1{\rm S}_0 \rightarrow {}^1{\rm P}_1$ transition frequency. In this article, we present two independent measurements of the absolute frequency of this transition performed with two different wavemeters using atomic fluorescence spectroscopy. The cancellation of Doppler shifts is obtained by fine tuning the angle between the probe laser and the atomic beam. The …
We report on measurements on the 5S-6P rubidium transition frequencies for rubidium isotopes with an absolute uncertainty of better than \SI{450}{kHz} for the 5S $\rightarrow$ 6P$_{1/2}$ transition and \SI{20}{kHz} for the 5S $\rightarrow$ 6P$_{3/2}$ transition, achieved by saturation absorption spectroscopy. From the results we derive the hyperfine splitting with an accuracy of \SI{460}{kHz} and \SI{30}{kHz}, respectively. We also verify the literature values for the isotope shifts as well as magnetic dipole constant and the electric quadrupole constant.
We present the detection of the highly forbidden $2^{3\!}S_1 \rightarrow 3^{3\!}S_1$ atomic transition in helium, the weakest transition observed in any neutral atom. Our measurements of the transition frequency, upper state lifetime, and transition strength agree well with published theoretical values, and can lead to tests of both QED contributions and different QED frameworks. To measure such a weak transition, we developed two methods using ultracold metastable ($2^{3\!}S_1$) helium atoms: low background direct detection of excited then decayed atoms for sensitive measurement of the transi…
Isotope shift spectroscopy with narrow optical transitions provides a benchmark for atomic structure calculations and has also been proposed as a way to constrain theories predicting physics beyond the Standard Model. Here, we have measured frequency shifts of the ${^1}S_0 \rightarrow {^3}P_1$ and ${^1}S_0 \rightarrow {^3}P_0$ transitions between all stable isotopes of strontium relative to ${^{88}}$Sr. This includes the first reported measurements of the ${^1}S_0 \rightarrow {^3}P_0$ isotope shift of ${^{88}}$Sr-${^{86}}$Sr and ${^{88}}$Sr-${^{84}}$Sr. Using the isotope shift measurements of …
Strontium ${}^{1}S_{0}\!\rightarrow\!{}^{1}P_{1}$ transition frequency measurements assisted by a photonic grating chip
Korea Research Institute of Standards and Science（韩国计量科学研究院）；Graduate School of Quantum Science and Technology, Korea Advanced Institute of Science and Technology（韩国科学技术院量子科学与技术研究生院）；Center for Next-Generation Platform Development, National NanoFab Center (NNFC)（国家纳米制造中心下一代平台开发中心）
Observation of Magnetically-Induced atomic transitions of the Cs 6S$_{1/2} \rightarrow 7$P$_{3/2}$ line at 456 nm
Institute for Physical Research – National Academy of Sciences of Armenia（亚美尼亚国家科学院物理研究所）；Université Marie et Louis Pasteur, Supmicrotech, CNRS, Institut FEMTO-ST（玛丽·路易·巴斯德大学，Supmicrotech，法国国家科学研究中心，FEMTO-ST研究所）
We present the current status for the direct measurement of the positronium hyperfine structure using the $\text{2}^\text{3}\text{S}_\text{1} \rightarrow \text{2}^\text{1}\text{S}_\text{0}$ transition. This experiment, currently being commissioned at the slow positron beam facility at ETH Zurich, will be the first measurement of this transition and the first positronium hyperfine splitting experiment conducted in vacuum altogether. This experiment will be free of systematic effects found in earlier experiments, namely the inhomogeneity in static magnetic fields and the extrapolation from dense…
Part-per-billion measurement of the $4^2S_{1/2} \rightarrow 3^2D_{5/2}$ electric quadrupole transition isotope shifts between $^{42,44,48}$Ca$^+$ and $^{40}$Ca$^+$
Raman Transitions in Collinear Laser Spectroscopy for High-Precision Frequency Measurements
Institut für Kernphysik, Technische Universität Darmstadt（达姆施塔特工业大学核物理研究所）；Helmholtz Research Academy Hesse for FAIR, GSI Helmholtzzentrum für Schwerionenforschung（黑森州FAIR亥姆霍兹研究院，GSI重离子研究中心）；Institute for Nuclear and Radiation Physics, KU Leuven（荷语鲁汶大学核与辐射物理研究所）
An optical reference based on a two-photon optical transition with ac Stark shift cancellation is proposed. The reference uses two interrogating laser fields at different frequencies. Compared to conventional optical two-photon references, the new approach offers the possibility for improved short-term stability resulting from a higher signal-to-noise and improved long-term stability due to active ac Stark shift cancellation. We demonstrate the ac Stark shift cancellation method on the $5s\,{^2S}_{1/2} \rightarrow 5d\,{^2D}_{5/2}$ two-photon transition in $^{87}$Rb.
We report measurements of the electric dipole matrix elements of the $^{133}$Cs $\ $ $6s\,^2S_{1/2} \rightarrow 7p\,^2P_{1/2}$ and $6s\,^2S_{1/2} \rightarrow 7p\,^2P_{3/2}$ transitions. Each of these determinations is based on direct, precise comparisons of the absorption coefficients between two absorption lines. For the $\langle 6s\,^2S_{1/2}||r|| 7p\,^2P_{3/2} \rangle$ matrix element, we measure the ratio of the absorption coefficient on this line with that of the D$_1$ transition, $6s\,^2S_{1/2} \rightarrow 6p\,^2P_{1/2}$. The matrix element of the D$_1$ line has been determined with high …
We report on the first coherent excitation of the highly forbidden $^2S_{1/2}\rightarrow{}^2F_{7/2}$ electric octupole (E3) transition in a single trapped ${}^{172}$Yb$^+$ ion, an isotope without nuclear spin. Using the transition in ${}^{171}$Yb$^+$ as a reference, we determine the transition frequency to be $642\,116\,784\,950\,887.6(2.4)\,$Hz. We map out the magnetic field environment using the forbidden $^2S_{1/2} \rightarrow{}^2D_{5/2}$ electric quadrupole (E2) transition and determine its frequency to be $729\,476\,867\,027\,206.8(4.4)\,$Hz. Our results are a factor of $1\times10^5$ ($3\…
Nuclear Charge Radii of Sr Isotopes: Reevaluation based on Transition Frequency Measurements in the $5s-5p-4d$ manifold in Sr$^+$
Technische Universität Darmstadt（达姆施塔特工业大学）；Helmholtz Forschungsakademie Hessen für FAIR, GSI Helmholtzzentrum für Schwerionenforschung（黑森FAIR赫尔霍兹研究中心，GSI重离子研究中心）；Physical Research Laboratory（物理研究实验室）；KU Leuven（荷语鲁汶大学）；University of Strathclyde（思克莱德大学）
