Tinsley Laboratories has developed process technology for fabricating ultra- precision aspheric optics used in space based and microlithography applications. The objective of the project is to significantly improve the process determinism, throughput, and cost by introducing ion-beam milling as a tool for final polishing of ultra-precise aspheric optics. We propose to transfer ion-beam milling capability which resides at the Oak Ridge National Laboratory and to apply this technology to the aspheric manufacturing process. The expected Phase I results are: 1) a quantitative determination of the ion-beam spatial pattern and stability, 2) material removal rates in several materials and measurements of surface figure at low, mid, high, and very high spatial periods, and 3) the verification, through polishing process modeling using actual data, that ion milling is applicable to final polishing ultra-precision optics. The expected Phase II results are: 1) the final figuring of several real-life ultra-precise aspheric surfaces via ion milling, and 2) the design of a Tinsley ion-milling system which will meet NASA and commercial needs. 7. Potential Commercial Applications The most direct application of the improved aspheric surface manufacturing technology is to the fabrication of ultra-precise optics used in advanced semiconductor microlithography stepper systems. While our focus is on aspheric optics, the process improvements will also aid in fabricating ultra-precise spherical surfaces which characterize more than 90% of the elements in stepper system designs. Other applications will directly benefit from a more deterministic aspheric fabrication process. Among these are flight simulation and air- and space-based remote sensing. These applications require high-precision rather than ultra-precision optics, but the anticipated process improvements will result in better production visibility, higher throughput, and lower cost in these areas as well. In addition, medium accuracy aspheric optics applications may also benefit from increased availability and lower cost due to the high convergence rate offered by ion milling on surfaces with difficult surface or outer-profile geometry. Representative applications are flight control instrumentation (head-up displays or helmet-mounted displays), specialized inspection tools, medical instrumentation, and specialized film and video lens systems.
