Production of Non-Traditional Optical Surfaces for Surveillance, Target Acquisition and Guidance

The objective of the proposed work is to demonstrate the feasibility of polishing 3.0 inch diameter ogive-shaped optical domes (fineness ratio 1.0-1.5) using a magnetorheological (MR) jet polishing process. The MR jet process utilizes an MR fluid mixturecomprised of magnetic particles and nonmagnetic abrasives, a delivery system capable of supplying a fluid jet with a velocity > 10 m/s, and an MR fluid jet shaper used to stabilize the shape of the jet. Interferometric characterization of the removalfunction and control of the positioning of the jet impingement on the optic surface by a computer numerically controlled (CNC) system will allow polishing with the required precision. An understanding of the effects of MR fluid characteristics, jetimpingement angle, standoff distance and jet speed on the removal rate of a variety of materials will enable this process to be used to polish complex, conformal shapes. Developing a process to manufacture precision polished conformal shapes is important for many applications. Ogive domes and other conformal shapes are immediately needed by the Department of Defense for surveillance, target acquisition and guidancesystems. Additional applications include commercial optics and a variety of other components.