Abstract. The field distribution of a Gaussian light beam introduces additional space-dependent phase shifts compared with that of a flat wave front. An expression for these phase corrections is derived for the case of a two-beam interferometer. The contribution from these diffraction-induced shifts to the g-value determined in absolute gravimetry is calculated. It is found that in the case of a beam waist of a few millimetres or smaller and, particularly, for unbalanced interferometers, a careful consideration of this effect is crucial if high accuracy is desired.

Print publication: Issue 1 (February 2007)
Received 11 April 2006
Published 2 January 2007