The Ronchi grating is applied to measure the large-aperture aspheric surfaces in a quantitative way on the basis of self-made software which includes Ronchi null grating design, collection of Ronchi graph, and data processing. The measured concave parabolic mirror has a diameter of 630 mm and an F number of 1.34. The measurement result is approximately the same as that of the ZYGO interferometer. This analysis software and test method establish a good foundation for the quantitative measurement of the big error about the large-aperture aspheric surfaces of the next generation telescope.
© 2009 Chinese Optics Letters
(100.1160) Image processing : Analog optical image processing
(110.6770) Imaging systems : Telescopes
(120.6650) Instrumentation, measurement, and metrology : Surface measurements, figure
(220.1250) Optical design and fabrication : Aspherics
Baiping Lei, Fan Wu, and Chenbo Zhou, "Quantitative measurement of Φ630 mm F/1.34 parabolic surfaces with Ronchi grating test method," Chin. Opt. Lett. 7, 590-592 (2009)