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Characterization of Precision Spheres With XCALIBIR



Ulf Griesmann, Johannes A. Soons, Quandou (. Wang


The geometry of a nearly spherical surface, for example that of a precision optic, is completely determined by the radius-of-curvature at one point and the deviation from the perfect spherical form at all other points of the sphere. Measurements of radius and form error can now be made with interferometers to remarkable accuracy. To measure the radius, a variant of the well known interferometric radius bench method is used. Careful alignment of phase measuring and displacement measuring interferometers enables us to achieve a standard measurement uncertainty for the sphere radius of about five parts in 10 7. The measurement of the form error is complicated because the entire sphere surface cannot be imaged in one measurement. Instead, 138 overlapping areas of the sphere surface are measured. A stitching algorithm is then employed to assemble these measurements into a form error map for the entire surface.
Proceedings Title
Frontiers in Optics Conference 2004
Conference Dates
October 10-14, 2004
Conference Location
Rochester, NY
Conference Title
Frontiers in Optics Conference 2004, OSA Technical Digest


Interferometry, precision spheres, XCALIBIR


Griesmann, U. , Soons, J. and Wang, Q. (2004), Characterization of Precision Spheres With XCALIBIR, Frontiers in Optics Conference 2004, Rochester, NY (Accessed May 22, 2024)


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Created January 1, 2004, Updated February 19, 2017