Noncollimated bidirectional shearing interferometer for measuring a long radius of curvature

摘要

A method for measuring a long radius of curvature with a modified half-aperture bidirectional shearing interferometer is described. A plane mirror of the interferometer is replaced with a test mirror, and the incident beam is decollimated by shifting of the source to equalize the widths of the bidirectional shearing fringes reflected from the plane and test mirrors. This method can be applied to concave and convex surfaces. (C) 1997 Optical Society of America.