Sub-dekahertz spectroscopy of199Hg+

James C. Bergquist, R. J. Rafac, Brent C. Young, James A. Beall, Wayne M. Itano, David J. Wineland, John L. Hall, Jun Ye
2001 Laser Frequency Stabilization, Standards, Measurement, and Applications  
Using a laser that is frequency-locked to a Fabry-Pérot etalon of high finesse and stability, we probed the 5d 10 6s 2 S 1/2 (F = 0, m F = 0) ↔ 5d 9 6s 2 2 D 5/2 (F = 2, m F = 0) electric-quadrupole transition of a single laser-cooled 199 Hg + ion stored in a cryogenic radio-frequency ion trap. We observed Fourier-transform limited linewidths as narrow as 6.7 Hz at 282 nm (1.06 x 10 15 Hz). The functional form and estimated values of some of the frequency shifts of the 2 S 1/2 ↔ 2 D 5/2 "clock"
more » ... 2 ↔ 2 D 5/2 "clock" transition (including the quadrupole shift), which have been calculated using a combination of measured atomic parameters and ab initio calculations, are given.
doi:10.1117/12.424455 fatcat:rcjxrcvqjvhmhmahntf5hhmxv4