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Proceedings Paper

In-Process Measurement Of Fast Aspherics
Author(s): John Bender; Graham Flint
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Paper Abstract

In the fabrication of fast aspheric mirrors having diameters in the 20-30 inch range, it ceases to be practical to introduce the required correction by polishing alone. One is faced, therefore, with aspheric figure control of a surface which cannot be tested optically. To overcome this problem we have adopted the use of precision profile monitors which can provide a prepolishing surface having an accuracy of better than one micron. Upon reaching the polished stage we have found that a wire tester provides the most convenient means for figure control. However, for the final stages of polishing, where local hand correction may be required, it is desirable that the wire tester be replaced by a full aperture interferometric technique; usually a null lens. Described in this paper is a three stage monitoring procedure which uses a profile monitor, a wire tester and a null lens. Accuracy and convenience of each technique are discussed. Also, suggestions are made concerning the optimum point at which one instrument should be exchanged for another.

Paper Details

Date Published: 4 April 1979
PDF: 7 pages
Proc. SPIE 0171, Optical Components: Manufacture and Evaluation, (4 April 1979); doi: 10.1117/12.957047
Show Author Affiliations
John Bender, International Laser Systems, Inc. (United States)
Graham Flint, International Laser Systems, Inc. (United States)

Published in SPIE Proceedings Vol. 0171:
Optical Components: Manufacture and Evaluation
Donald S. Nicholson, Editor(s)

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