26 March 1992 Large optics from silicon carbide
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Silicon carbide (SiC) has become a legitimate competitor to beryllium (Be) for large lightweight mirrors due to its high stiffness to weight ratio and low thermal expansion. However, there are many kinds of SiC and some are better suited for mirrors than others. After a comparison of the various SiC types we described one type of reaction bonded SiC that can be near-net-shape fabricated into very lightweight mirrors in sizes ranging from a few centimeters to greater than two meters. Lightweight spherical mirrors of 0.18 and 0.50 m diameter have been fabricated and polished to very low surface roughness. The blank and optical fabrication techniques are described, and characterization data are presented for uncoated polished surfaces. These mirrors have surface roughness of 8 - 15 angstroms rms and (lambda) /10 figure
© (1992) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Roger A. Paquin, Roger A. Paquin, Matthew B. Magida, Matthew B. Magida, Cynthia L. Vernold, Cynthia L. Vernold, } "Large optics from silicon carbide", Proc. SPIE 1618, Large Optics II, (26 March 1992); doi: 10.1117/12.58042; https://doi.org/10.1117/12.58042


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