Precise measurements of UV atomic lines: Hyperfine structure and isotope shifts in the 398.8 nm line of Yb

Abstract

PACS. 32.30.Jc -Visible and ultraviolet spectra. PACS. 32.10.Fn -Fine and hyperfine structure. PACS. 42.62.Fi -Laser spectroscopy.Abstract. -We demonstrate a technique for frequency measurements of UV transitions with sub-MHz precision. The frequency is measured using a ring-cavity resonator whose length is calibrated against a reference laser locked to the D2 line of 87 Rb. We have used this to measure the 398.8 nm 1 S0 ↔ 1 P 1 line of atomic Yb. We report isotope shifts of all the seven stable isotopes, including the rarest isotope 168 Yb. We have been able to resolve the overlapping 173 Yb(F = 3/2) and 172 Yb transitions for the first time. We also obtain highprecision measurements of excited-state hyperfine structure in the odd isotopes, 171 Yb and 173 Yb. The measurements resolve several discrepancies among earlier measurements.Precise measurements of the frequencies of atomic transitions are an important tool in expanding our knowledge of physics. For example, precise measurement of the D 1 line in Cs [1] combined with an atom-interferometric measurement of the photon recoil shift [2] could lead to a more accurate determination of the fine-structure constant α. In addition, hyperfinestructure and isotope-shift measurements in atomic lines can help in fine-tuning the atomic wavefunction, particularly due to contributions from nuclear interactions. This is important when comparing theoretical calculations with experimental data in atomic studies of parity violation [3]. The most precise optical frequency measurements to date have been done using the recently developed frequency-comb method with mode-locked lasers [1], with errors below 100 kHz being reported. However, to the best of our knowledge, this technique has not yet been applied to UV spectroscopy, which relies on older and less-accurate techniques.In this Letter, we present the most comprehensive study of the 398.8 nm 1 S 0 ↔ 1 P 1 line of atomic Yb. Yb (Z=70) is an attractive candidate for studying atomic parity violation [4] and the search for a permanent electric-dipole moment in atoms [5]. Laser-cooled Yb has also been proposed for frequency-standards applications [6]. The 1 S 0 ↔ 1 P 1 line is widely used in laser-cooling experiments [5,7]. Over the years, there has been much interest in this line, and its isotopic and hyperfine components have been measured using a variety of techniques -level-crossing and anti-crossing spectroscopy [8,9,10], Fabry-Perot cavity [11], saturatedabsorption spectroscopy [12], photon-burst spectroscopy [13], and most recently using optical

Paramagnetic Faraday rotation with spin-polarized ytterbium atoms

“…10, we show the absorption spectrum with the probe light. It shows that the atomic beam was so well collimated that the linewidth caused by the transverse Doppler broadening is Γ * = 2π × 57 MHz, about twice of the natural linewidth Γ , obtained from the fitting with the isotope shifts and the hyperfine splittings [20], and the relative transition probabilities for π polarized light among the hyperfine sublevels (Table 2). In the fitting, we approximated the Doppler broadeneng Γ * as the natural line width Γ , known as T * 2 → T 2 approximation.…”

“…4 Rotation angle of spin-1/2 isotope. Here, we used the value of the hyperfine splitting, ω (1/2) − ω (3/2) = 2π × 320 MHz [20].…”

A frequency-stabilized light source at 399 nm using an Yb hollow-cathode lamp

“…As for those lines involving multiple isotope transitions, our results are in good agreement with the results reported by Nizamani et al, 11) but could not be compared with the results that resolve the isotope transitions by fitting the spectrum theoretically. 10,12,[30][31][32][33][34] It is worth noting here that although the absolute frequencies of each isotope transition may be different in experiments using a HCL and an atomic beam, isotope frequency shifts are basically independent of the experimental methods. frequency comb in their frequency measurement, 12) it is reasonable to consider that their re-10/14 173 Yb, 1 S 0 (F = 1/2) − 1 P 1 (F = 3/2) 173 Yb, 1 S 0 (F = 1/2) − 1 P 1 (F = 7/2) 171 Yb, 1 S 0 (F = 1/2) − 1 P 1 (F = 3/2) 837.72(13) 170 Yb, 1 S 0 − 1 P 1 1169.60(13) 171 Yb, 1 S 0 (F = 1/2) − 1 P 1 (F = 1/2) sult is more reliable than the earlier two measurements.…”

Absolute-frequency measurements of theD2line and fine-structure interval inK39

“…The errors in our frequency measurement technique have been discussed extensively in earlier publications [2,6,7]. We present here a brief overview for the sake of completeness.…”

“…We have recently developed a technique for measuring the absolute frequencies of optical transitions with sub-MHz precision [6,7]. The frequency is measured using a ring-cavity resonator whose length is calibrated against a reference laser locked to the D 2 line of 87 Rb.…”