Integration of Full-Spectrum Metrology and Polishing for Rapid Production of Large Aspheres, Phase II

We propose to design, build, and test a major new instrument capable of both measuring and polishing the surface of aspheric mirrors up to 1.2 meters in diameter, and up to f-0.5 in speed, either concave or convex. In the successful Phase I proposal, we laid out the instrument to the component level, and laid out and analyzed every critical subsystem. We also investigated and experimented with the fluid jet polishing to be used by this instrument, setting the stage for further experiments and ultimate usage in Phase II. The metrology accuracy goals, supported by previous measurements, are 1 nanometer rms for full aperture figure, and 0.1 nm rms for mid-frequency and micro-roughness. The full-aperture and mid-frequency metrology approaches are based on previous successful SBIR projects, while the micro-roughness metrology is an improvement on standard Total Integrated Scatter measurements developed under Phase I. All of the metrology instrumentation is integrated into a single measurement head. At the end of the project, we will polish and measure an f-1.1, 560 mm parabola, and possibly an 890 mm, f-2.5 sphere. More »