Compensation of systematic errors in a compact atomic beam frequency standard due to evanescent field inside a Ramsey cavity

Abstract

Systematic errors due to evanescent field inside an E-plane type Ramsey cavity are corrected by introducing an extended square pulse profile in our Ramsey spectral analysis. This procedure is crucial for the proper operation of thermal beam based atomic frequency standards with short cavities. By accounting for the spatial extent of the field inside the cavity, the method enables a correct calculation of transition probability for atoms at the interaction region. The authors demonstrate that the systematic errors in quadratic Doppler and end-to-end cavity phase shifts can be reduced by an order of magnitude.