Development of a Metrology Workstation for Full-aperture and Sub-aperture Stitching Measurements

In this work we examine how stitching interferometry can be used to provide both absolute calibration and also increased spatial resolution for the interferometric measurement of precision surfaces; both are important aspects of precision surface production. We examine the process of stitching as used to form a synthesized full-aperture measurement of a part from sub-aperture data. We then explain how to estimate and remove systematic errors in the interferometer by using the plurality of sub-aperture data sets thereby eliminating the need for a master calibration piece.We briefly describe our automated stitching system and how it fulfils a specific need in the optics industry to enable high-resolution and calibrated measurements on large aperture optical surfaces. Finally we conclude with some example measurements of real surfaces using the stitching system built at our lab.