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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 20, Iss. 18 — Aug. 27, 2012
  • pp: 19787–19798

Edges in CNC polishing: from mirror-segments towards semiconductors, paper 1: edges on processing the global surface

David Walker, Guoyu Yu, Hongyu Li, Wilhelmus Messelink, Rob Evans, and Anthony Beaucamp  »View Author Affiliations

Optics Express, Vol. 20, Issue 18, pp. 19787-19798 (2012)

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Segment-edges for extremely large telescopes are critical for observations requiring high contrast and SNR, e.g. detecting exo-planets. In parallel, industrial requirements for edge-control are emerging in several applications. This paper reports on a new approach, where edges are controlled throughout polishing of the entire surface of a part, which has been pre-machined to its final external dimensions. The method deploys compliant bonnets delivering influence functions of variable diameter, complemented by small pitch tools sized to accommodate aspheric mis-fit. We describe results on witness hexagons in preparation for full size prototype segments for the European Extremely Large Telescope, and comment on wider applications of the technology.

© 2012 OSA

OCIS Codes
(110.6770) Imaging systems : Telescopes
(220.0220) Optical design and fabrication : Optical design and fabrication
(220.5450) Optical design and fabrication : Polishing
(230.4040) Optical devices : Mirrors

ToC Category:
Optical Design and Fabrication

Original Manuscript: June 7, 2012
Revised Manuscript: August 3, 2012
Manuscript Accepted: August 3, 2012
Published: August 14, 2012

David Walker, Guoyu Yu, Hongyu Li, Wilhelmus Messelink, Rob Evans, and Anthony Beaucamp, "Edges in CNC polishing: from mirror-segments towards semiconductors, paper 1: edges on processing the global surface," Opt. Express 20, 19787-19798 (2012)

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