Suppression of spurious phase shifts in an optical frequency standard

We have analyzed two types of time-domain atom-light interferometers realized by a series of beam splitting copropagating or counterpropagating laser pulses. We show how a combination of both types can be used to identify and to reduce spurious systematic phase shifts in a high-precision optical frequency standard. In particular, we have investigated theoretically and experimentally the influence of minute wave front curvatures and gravitational acceleration. Application of this technique to a Ca optical frequency standard leads to estimates of the relative uncertainty due to wave front curvature and gravitational acceleration of 8/spl times/10/sup -15/ and 6.5/spl times/10/sup -16/, respectively.