Absolute frequency measurement of the²S_1/2–²F_7/2electric octupole transition in a single ion of¹⁷¹Yb⁺with 10⁻¹⁵fractional uncertainty

Abstract

An absolute frequency measurement has been made of the 2S1/2–2F7/2 electric octupole transition in a single ion of 171Yb+. The implementation of a diode-based probe laser stabilized to this highly forbidden transition has resulted in an improvement of more than one order of magnitude upon the lowest published uncertainty. After correcting for systematic shifts, the frequency was determined to be 642 121 496 772 646.22 (67) Hz. This corresponds to a fractional uncertainty of 1.0 × 10−15.