Removal of mid spatial-frequency features in mirror segments

G. Yu; H. Li; D. Walker

doi:10.2971/jeos.2011.11044

Journal of the European Optical Society - Rapid publications, Vol 6 (2011)

Removal of mid spatial-frequency features in mirror segments

G. Yu, H. Li, D. Walker

Abstract

BoXâ„¢ grinding technology has been adopted in our E-ELT segment process. The mid-spatial frequency features generated can be removed by several â€˜smoothingâ€™ processes. We have reported here a novel method that can smooth these features whilst avoiding edge down-turn. This process can be scaled up to E-ELT segment fabrication time-scale. It has been experimentally demonstrated that the surface quality is good enough for subsequent Zeeko form correction technology to achieve form specifications.

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