1. Verification and in situ calibration of large-aperture null correctors for convex aspheric mirrors.
- Author
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Xue, Shuai, Chen, Shanyong, Tian, Ye, Lu, Jinfeng, and Hu, Hao
- Subjects
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OPTICAL apertures , *CONVEX lenses , *ERRORS , *IN situ remediation , *ASPHERICAL lenses , *CONFIRMATION (Logic) , *PREVENTION - Abstract
Interferometric test of large convex aspheres with high accuracy is still an urgent problem. Adopting a large-aperture null corrector is usually inevitable, and it is imperative to certify the large-aperture null optics in case incorrect final shape of the aspheric mirror is obtained. Moreover, it is necessary to calibrate and remove errors of the large-aperture null lens and trace errors to surfaces that are easy to obtain high accuracy. For these purpose, this paper presents an in situ calibrated null test method. The large-aperture null corrector for convex aspheric mirror is verified and calibrated by a wisely designed small aperture certifying null whose surfaces are either flat or spherical which are easy to be fabricated, measured and assembled. A redundant test is implemented by a Zygo VeriFire Asphere interferometer for cross test. Compared with existing methods of certificating null correctors which utilize an expensive CGH or a self-aligning aspherical mirror, the presented method finally traces errors of a large-aperture null corrector to small aperture flat and spherical surfaces thus costs are expected to be saved dramatically. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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