Related Experiment Video
Updated: Jun 28, 2026

Demonstration of Equal-Intensity Beam Generation by Dielectric Metasurfaces
Published on: June 7, 2019
Interferometric null test of a deep parabolic reflector generating a Hertzian dipole field
Gerd Leuchs1, Klaus Mantel, Andreas Berger
1Friedrich Alexander University of Erlangen-Nürnberg, Staudtstr. 7/B2, 91058 Erlangen, Germany.
Abstract:
We report on interferometric characterization of a deep parabolic mirror with a depth of more than five times its focal length. The interferometer is of Fizeau type; its core consists of the mirror itself, a spherical null element, and a reference flat. Because of the extreme solid angle produced by the paraboloid, the alignment of the setup appears to be very critical and needs auxiliary systems for control. Aberrations caused by misalignments are removed via fitting of suitable functionals provided by means of ray tracing simulations. It turns out that the usual misalignment approximations fail under these extreme conditions.
Related Concept Videos
Reflective Property of Parabolas
Polar Coordinates: Problem Solving
Interference and Diffraction
Surface Area Calculations
Induced Electric Dipoles
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
Centroid for the Paraboloid of Revolution
The centroid for the paraboloid of revolution is the point where all the mass of the paraboloid is concentrated. This centroid is important for engineering applications, as it determines how forces are...
