A number of 150 mm apertures in 250 mm diameter plano-concave optics with figure errors of a few nm were carefully tested using phase measuring interferometry and the data reduced using pixel based absolute testing techniques. We discuss some of the data reduction techniques used, as well as the precautions taken to verify the accuracy of the results. After accounting for systematic errors introduced by interferometer imaging, we show that the surfaces can be characterized to a few nm peak-to-valley over spatial scales from the measurement aperture to a few mm.
Proceedings Title: Proceedings of SPIE, Optical Manufacturing and Testing II, H. Philip Stahl, Editor
Conference Dates: July 27, 1997
Conference Location: San Diego, CA
Conference Title: LIGO
Pub Type: Conferences
absolute testing, interferometry, LIGO, optical testing