Lambda-over-one-thousand metrology results for steep aspheres using a curvature profiling technique

Paul E. Glenn

doi:10.1117/12.134847

Translator Disclaimer

1 January 1992 Lambda-over-one-thousand metrology results for steep aspheres using a curvature profiling technique

Paul E. Glenn

Author Affiliations +

Proceedings Volume 1531, Advanced Optical Manufacturing and Testing II; (1992) https://doi.org/10.1117/12.134847
Event: San Diego, '91, 1991, San Diego, CA, United States

Abstract

We have previously described a new noncontact profiling technique that involves measuring the test surface curvature on a point-by-point basis. Curvature is measured by simultaneously measuring the test surface slope at two slightly displaced locations. As the pair of sensing beams is scanned along the test piece, a profile of curvature is built, from which the height profile is deduced. The sensing of curvature eliminates the need for a reference surface, and makes the approach insensitive to all types of vibration and drift, both in surface height and in surface slope. In this paper, we discuss some of our more recent calibration and measurement efforts in testing steep optics. We also discuss test piece alignment. This aspect of metrology is always of concern, especially in the case of steep optics in general, and steep aspheres in particular. We show that the curvature profiling technique is inherently much less sensitive to unknown misalignments and variations in scanning geometry than a height profiling or slope profiling technique.

Citation Download Citation

Paul E. Glenn "Lambda-over-one-thousand metrology results for steep aspheres using a curvature profiling technique", Proc. SPIE 1531, Advanced Optical Manufacturing and Testing II, (1 January 1992); https://doi.org/10.1117/12.134847

ACCESS THE FULL ARTICLE