Recent developments in finishing of deep concave, aspheric, and plano surfaces utilizing the UltraForm 5-axes computer controlled system

Abstract

OptiPro Systems has developed a robust 5-axes computer controlled platform, for implementation of the sub-aperture UltraForm Finishing (UFF) process specifically focused on finishing AlON, spinel and transparent polycrystalline alumina (PCA) steep concave, convex and ogive shaped infrared domes and aspheres. Traditional manufacturing of optical components typically involves a three-stage process: grinding, lapping and polishing. The lapping and polishing stages are focused at reducing the surface roughness while preserving the integrity of the form acquired during grinding. Polishing of non spherical and irregular shapes is nearly impossible using traditional full aperture techniques. However, finishing these non-spherical and irregular shapes is possible using UltraForm Finishing. A brief description of the evolution of the UltraForm hardware and processes will be presented, with the current hardware developments. A review of the results with regard to form/figure and roughness improvements on glass, AlON and transparent PCA will be presented using a variety of grinding and finishing abrasives. Differences in the abrasive materials, some bound, and others loose in a slurry have a large impact on the process cycle time and resultant surface roughness.