Radial shearing interferometer for in-process measurement of diamond turning

A stable interferometer using two zone plates to measure concave mirror figure is developed. The principle of the measurement is based on the radial shearing interference in which the measuring wavefront from the entire mirror surface under test is referred to that of the central part. On-machine experiments showed that the interferometer would be applicable to the in-process measurement for a diamond turning in about 0.06 micrometers p-p accuracy.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.