Re. Drullinger et al., ERROR ANALYSIS OF THE NIST OPTICALLY PUMPED PRIMARY FREQUENCY STANDARD, IEEE transactions on instrumentation and measurement, 42(2), 1993, pp. 453-456
The major sources of systematic error in the NIST optically pumped pri
mary frequency standard have been evaluated with an uncertainty of a f
ew parts in 10(14). The cavity end-to-end phase shift is the only item
which differed markedly from expectations based on the design and/or
measurements made during assembly. We think the difference is attribut
able to the physical dimensions of the cavity and not to its asymmetry
. The device will begin to function as the U.S. primary frequency stan
dard, even before planned extensions to the analysis presented here an
d improvements to the laser and servo electronics allow evaluation at
its full design accuracy of one part in 10(14).