CAN - Optical Frequency Comb

Comparison of optical frequency standards is essential for verifying that the clocks both locally and remotely at other national metrological institutes all agree to within their quoted uncertainties. These quoted uncertainties can be as low as ~1e-18, and so agreement between multiple clocks all operating at this level is required to verify that uncertainty. Remote clock comparisons at NPL, or between NPL and other European NMIs, are only possible at this uncertainty using optical frequency combs and telecoms opti...