Article

Optimum Configuration Of The Offner Null Corrector: Testing An F/1 Paraboloid

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Abstract

Three designs of the Offner type that can be used to test an F/1 paraboloid mirror are discussed. A tolerancing analysis is performed in order to design a null corrector with a performance insensitive to small fabrication and alignment errors. It is found that there is no optimum configuration, but solutions with different properties do exist.

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... Null optics are additional optics that must be added to the system, and they are often referred to as a null lens, null corrector, or null compensator. Refractive, reflective, and diffractive elements have been employed as null compensators (Offner 1963;Sasian 1989;McCann 1991;Offner and Malacara 1992;Chen 1993). Asphere wavefront at the location of the test part, leading to errors in the surface figure (Allen et al. 1990). ...
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Chapter
Introduction Some Methods to Test Aspheric Wavefronts Imaging of the Interference Pattern in Non-Null Tests Some Null Testing Configurations Testing of Convex Hyperboloidal Surfaces Testing of Cylindrical Surfaces Early Compensators Refractive Compensators Reflecting Compensators Other Compensators for Concave Conicoids Interferometers Using Real Holograms Interferometers Using Synthetic Holograms Aspheric Testing with Two-Wavelength Holography Wavefront Stitching
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