Abstract

In classical polishing techniques, each geometry of the part requires a dedicated, appropriately shaped polishing lap. In addition, the polishing lap shape changes with time and must be periodically reconditioned to obtain consistent removal efficiency. The traditional method therefore does not offer a flexible, cost-effective option for finishing, particularly for advanced optical shapes such as aspheres or conformal optics. A new precision polishing method called magnetorheological finishing (MRF) has been developed to overcome fundamental limitations of traditional finishing techniques [1]. MRF may produce surface accuracy of the order of 10 nm peak to valley and surface micro-roughness less than 10Å on optical glasses, single crystals (calcium fluoride, silicon) and ceramics. High precision spheres and flats, nearly any asphere, square and rectangular aperture optics, prisms and cylindrical optics may be corrected and finished with MRF. Currently manufactured by QED Technologies, MRF equipment is being employed in the production of high precision optics in North America, Europe, and Asia. In this paper, it will be shown that the future utilization of unique properties of magnetorheological fluid offers several advantages over current MRF systems. The next generation of MRF machines practically is not limited in the size of large optics, has the advantage in polishing concave optics and has a more stable and easier to maintain delivery system.

© 2002 Optical Society of America