Showing papers by "Wrocław University of Technology published in 1969"

Electric-field distribution in the focal region of an offset paraboloid

Abstract: The electric field in the vicinity of the focus of a finite offset-paraboloid reflector, illuminated by a linearly polarised plane wave, is investigated. The paper begins with a general formulation of the reflected field calculation procedure for an arbitrary reflecting surface. The formulation is then specialised to apply to an offset paraboloid. Extensive computed data of the field in the focal region of an offset paraboloid are presented and compared with the field distribution in the focal region of a symmetrical paraboloid. It is shown that the electric-field distribution in the focal region of an offset paraboloid is almost the same as for a symmetrical paraboloid with the equivalent focal length.

Minimal astigmatism surfaces.

Abstract: It has been pointed out that the meridional object and image foci as well as the meridional center of curvature will lie on the same straight line if the condition Δ(n cos2i/t) = Δ(n/t) is satisfied. The surfaces fulfilling this condition do not introduce astigmatism; hence they have been called minimal astigmatism surfaces. The generalized aplanatic points are defined and discussed, and the conditions for the incidence angle, which make it possible to replace the aspheric surfaces by spherical ones, are considered. A general method for the calculation of the minimal astigmatism surfaces is described.