Hannover 2010 – wissenschaftliches Programm
Q 42.2: Vortrag
Donnerstag, 11. März 2010, 10:45–11:00, A 310
High-resolution laser spectroscopy of the 2S1/2 − 2F7/2 octupole transition in 171Yb+ — •Nils Huntemann, Ivan Sherstov, Maxim Okhapkin, Burghard Lipphardt, Christian Tamm, and Ekkehard Peik — Fachbereich Zeit und Frequenz, Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
We present our results on the spectroscopy of the electric octupole transition 2S1/2(F=0) → 2F7/2(F=3) of a single trapped laser-cooled 171Yb+ ion. This transition is of special interest as an optical frequency standard because the 2F7/2 state has an extremely long natural lifetime of approximately 6 years. As a result, the stability of the frequency standard will not be limited by its natural linewidth, but by the laser system. The strong dependence of the transition frequency on the value of the fine structure constant α suggests long-term comparisons with other optical frequency standards, especially the 2S1/2−2D3/2 electric quadrupole transition in 171Yb+, in order to test the constancy of α.
We developed a diode-laser system with a relative frequency stability better than 2×10−15 at 1 s and a very low nonlinear frequency drift to excite this transition. We obtain excitation spectra of the octupole transition with a resonant excitation probability of about 65 % and an essentially Fourier transform-limited resolution of 13 Hz. These results compare favourably with previous work [Hosaka et al., Phys. Rev. A 79 033403 (2009)].