title: Large aperture ac interferometer for optical testing.
abstract: A 20-cm clear aperture modified Twyman-Green interferometer is described. The system measures phase with an AC technique called phase-lock interferometry while scanning the aperture with a dual galvanometer scanning system. Position information and phase are stored in a minicomputer with disk storage. This information is manipulated with associated software, and the wavefront deformation due to a test component is graphically displayed in perspective and contour on a CRT terminal.
authors.forename: D T
authors.initials: DT
authors.lastname: Moore
authors.forename: R
authors.initials: R
authors.lastname: Murray
authors.forename: F B
authors.initials: FB
authors.lastname: Neves