Opportunities Knock with a More Stable Optical Clock

摘要

Recently, there has been rapid progress in the development of a new generation of optical atomic clocks that operate at frequencies around five orders of magnitude higher than their microwave predecessors. Because the instability of an atomic clock is inversely proportional to its operating frequency, optical clocks offer the prospect of achieving substantial improvements in measurement precision, potentially at the level of 1 part in 1018 for averaging times of a few hundred seconds. On page 1215 of this issue, Hinkley et al. (1) report an important step toward reaching this goal: a comparison between two ytterbium optical lattice clocks that demonstrates unprecedented clock instability of 1.6 parts in 10~(18) for an averaging time of 7 hours.