Magnetorheological finishing of large and lightweight optics

摘要: Magnetorheological finishing (MRF) is a production proven, sub-aperture polishing process for flat, spherical, aspherical, and cylindrical optics in the size range of 10 - 400 mm. Surface figure accuracy better than 30 nm peak-to-valley (better 5 rms), microroughness 1 rms routinely achieved on variety glasses, glass ceramics single crystal materials. Recent work has demonstrated applicability MRF larger apertures lightweight optics. A platform capable 1000 mm already been built. Engineering studies extending aperture further are underway. Finishing large, mirrors additional challenges because non-uniform support face-sheet requires special efforts to avoid quilting errors caused by print-through cell structure due fabrication processes, gravity and/or temperature effects. Unique characteristics such as competitively high, stable removal rate, conformal nature tool shear mode material give it advantages this class Specifically, avoids generating high rate convergence correcting created other or An important quality that shown inserting into manufacturing can substantially reduce subsurface damage (SSD), increasing laser threshold surface, providing use mirror high-energy applications. Supporting results will be given paper.