Related papers: Accurate spectroscopy of Sr atoms
The absolute frequency of the $^{87}{\rm Sr}$ lattice clock transition was evaluated with an uncertainty of $1.1\times 10^{-15}$ using a frequency link to the international atomic time (TAI). The frequency uncertainty of a hydrogen maser…
We present a new measurement of the $1S-3S$ two-photon transition frequency of hydrogen, realized with a continuous-wave excitation laser at 205 nm on a room-temperature atomic beam, with a relative uncertainty of $9\times10^{-13}$. The…
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…
We present a measurement of the hydrogen $2$S$_{1/2}-8$D$_{5/2}$ transition performed with a cryogenic atomic beam. The measured resonance frequency is $\nu=770649561570.9(2.0)$ kHz, which corresponds to a relative uncertainty of…
We present a new evaluation of an 87Sr optical lattice clock using spin polarized atoms. The frequency of the 1S0-3P0 clock transition is found to be 429 228 004 229 873.6 Hz with a fractional accuracy of 2.6 10^{-15}, a value that is…
We demonstrate a one-dimensional optical lattice clock with a spin-polarized fermionic isotope designed to realize a collision-shift-free atomic clock with neutral atom ensembles. To reduce systematic uncertainties, we developed both Zeeman…
We report the direct excitation of the highly forbidden (6s^2) 1S0 - (6s6p) 3P0 optical transition in two odd isotopes of ytterbium. As the excitation laser frequency is scanned, absorption is detected by monitoring the depletion from an…
Optical lattice clocks based on the narrow (5s2)1S0 - (5s5p)3P0 transition in neutral strontium (Sr) are among the most precise and accurate measurement devices in existence. Although this transition is completely forbidden by selection…
We describe a high-resolution spectroscopy method, in which the detection of single excitation events is enhanced by a complete loss of coherence of a superposition of two ground states. Thereby, transitions of a single isolated atom nearly…
We develop a simple technique to accurately measure frequency differences between far lying resonances in a spectroscopy signal using a single laser. This technique was used to measure the isotope shift of the cooling transition of…
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…
We demonstrate a technique for directly measuring the fine-structure interval in alkali atoms using two frequency-stabilized diode lasers. Each laser has a linewidth of order 1 MHz and precise tunability: one laser is tuned to a hyperfine…
We report the first direct frequency comparison between two multi-ion optical clocks based on the S$_{1/2}$ to D$_{5/2}$ transition in \Ca and \Sr ions. Using linear chains of up to nine \Ca ions and six \Sr ions, we demonstrate improved…
We report our measurements of the absolute transition frequencies of 5P_3/2,F = 3 to nS and nD Rydberg states of 87Rb with high principal quantum numbers in a wide range of values (n = 45-124). The measurements were performed using Rydberg…
We report on an evaluation of an optical clock that uses the $\phantom{}^2S_{1/2} \rightarrow \phantom{}^2D_{5/2}$ transition of a single $^{88}$Sr$^+$ ion as the reference. In contrast to previous work, we estimate the effective…
We have measured hyperfine structure in the first-excited $P$ state ($D$ lines) of all the naturally-occurring alkali atoms. We use high-resolution laser spectroscopy to resolve hyperfine transitions, and measure intervals by locking the…
We report an uncertainty evaluation of an optical lattice clock based on the $^1S_0\leftrightarrow^3P_0$ transition in the bosonic isotope $^{174}$Yb by use of magnetically induced spectroscopy. The absolute frequency of the…
We report photoassociative spectroscopy of $^{88}$Sr$_2$ in a magneto-optical trap operating on the ${^1S_0}\to{^3P_1}$ intercombination line at 689 nm. Photoassociative transitions are driven with a laser red-detuned by 600-2400 MHz from…
Branching fractions were measured for electric dipole transitions from the 5p upper levels to the 5s levels in neutral krypton atoms. The measurements were made with a wall-stabilized electric arc and a 2m monochromator for the spectral…
We present absolute frequency measurement of the unperturbed P7 P7 O$_2$ B-band transition with relative standard uncertainty of $2\times10^{-11}$. We reached the level of accuracy typical for Doppler-free techniques, with Doppler-limited…