Related papers: Precise fine-structure and hyperfine-structure mea…
It has been proposed that the radio-frequency electric-dipole (E1) transition between two nearly degenerate opposite-parity states in atomic dysprosium should be highly sensitive to possible temporal variation of the fine structure constant…
Atmospheric carbon dioxide concentrations are being closely monitored by remote sensing experiments which rely on knowing line intensities with an uncertainty of 0.5% or better. We report a theoretical study providing rotation-vibration…
We measure the transverse velocity distribution in a thermal Sr atomic beam precisely by velocity-selective saturated fluorescence spectroscopy. The use of an ultrastable laser system and the narrow intercombination transition line of Sr…
We report precise measurements of ground-state, $\lambda$-doublet microwave transitions in the hydroxyl radical molecule (OH). Utilizing slow, cold molecules produced by a Stark decelerator we have improved over the precision of the…
We describe a thin-film superconducting Nb microwave resonator, tunable to within 0.3 ppm of the hyperfine splitting of $^{87}$Rb at $f_{Rb}=6.834683$ GHz. We coarsely tuned the resonator using electron-beam lithography, decreasing the…
Additional clock transitions of ytterbium atoms based on inner-shell orbital transition could benefit the search for new physics beyond the Standard Model. Observation of these transitions with high resolution is a prerequisite for making…
Precision isotope shift metrology in the deep-UV region has been performed for all bosonic isotopes of mercury with a zero nuclear spin, by using the technique of frequency-comb referenced, wavelength-modulated, saturated absorption…
The serrodyne principle enables shifting the frequency of an electromagnetic signal by applying a linear phase ramp in the time domain [1]. This phenomenon has been exploited to frequency-shift signals in the radiofrequency (RF), microwave…
We describe experiments with an optical frequency standard based on a laser cooled $^{171}$Yb$^+$ ion confined in a radiofrequency Paul trap. The electric-quadrupole transition from the $^2S_{1/2}(F=0)$ ground state to the $^2D_{3/2}(F=2)$…
A method for performing a precision measurement of the Rydberg constant, $R_{\infty}$, using cold circular Rydberg atoms is proposed. These states have long lifetimes, as well as negligible quantum-electrodynamics (QED) and no…
An experimental method is developed for the robust frequency stabilization using a high-finesse cavity when the laser exhibits large intermittent frequency jumps. This is accomplished by applying an additional slow feedback signal from…
We report the development of a method for eliminating background-induced systematic shifts affecting precise measurements of saturation absorption signals. With this technique, we measured the absolute frequency of the $6s^2~^1\text{S}_0…
We report on higly accurate absolute frequency measurement against a femtosecond frequency comb of 6 saturated absorption lines of formic acid (HCOOH) with an accuracy of 1 kHz. We also report the frequency measurement of 17 other lines…
We measure the hyperfine structure of $nP_{1/2}$ Rydberg states using mm-wave spectroscopy on an ensemble of laser-cooled $^{85}$Rb atoms. Systematic uncertainties in our measurement from the Zeeman splittings induced by stray magnetic…
The brightest southern quasar above redshift $z=1$, HE 0515$-$4414, with its strong intervening metal absorption-line system at $z_{abs}=1.1508$, provides a unique opportunity to precisely measure or limit relative variations in the…
The frequency ratio of the 1S0(F=1/2)-3P0(F=1/2) clock transition in 171Yb and the 1S0(F=9/2)-3P0(F=9/2) clock transition in 87Sr is measured by an optical-optical direct frequency link between two optical lattice clocks. We determined the…
In this paper, we experimentally report the saturated absorption spectroscopy (SAS) and frequency locking (FL) of a narrow-band DBR laser with 0.5MHz linewidth on the LD2-transition of Rb atoms.
We report the measurement of hyperfine splitting in the $7d$ $^{2}D_{3/2}$ state of $^{133}$Cs using high resolution Doppler-free two-photon spectroscopy in a Cs vapor cell. We determine the hyperfine coupling constants $A = 7.3509(9)$ MHz…
In this work the inhomogeneous (zero-phonon line) and homogeneous line widths, and one projection of the permanent electric dipole moment change for the Ce 4f-5d transition in Y_2SiO_5 were measured in order to investigate the possibility…
We propose a new frequency standard based on a $4f^{14} 6s6p~ ^3\!P_0 - 4f^{13} 6s^2 5d ~(J=2)$ transition in neutral Yb. This transition has a potential for high stability and accuracy and the advantage of the highest sensitivity among…