Beugungstheoretische Behandlung eines Differentialinterferometers für ausgedehnte Phasenobjekte

The diffraction theory of image construction has been used, in the case of a differential interferometer employing a Wollaston prism, to derive the position of the interference fringes in dependence upon the phase object and the prism position. This procedure is not only more correct, but proves also to be simpler than the corresponding geometric-optical treatment. An example is presented in which the fringe shift resulting from a symmetrical gas flow has been used to evaluate the gradient of the optical path perpendicular to the rotational axis of symmetry.