Correction of Complex Figure Errors on Mirror Surfaces by Ion Figuring

Abstract

Until recently the correction of surface figure errors on optical surfaces (lenses, mirrors) by the use of inert ion beams has been limited to small area optics with relatively minor error profiles. Two techniques have been documented; the use of masks to define the removal pattern generated with the use of a large area ion beam and the use of scanning motions applied to small size ion beams. For the former operation, the masks may be rotated (1) to correct axisymmetric errors or remain stationery to provide discrete area removal. (The use of successive masks of various shapes produces an integrated pattern of any configuration.)