Fabrication and testing of large flats

Julius Yellowhair, Peng Su, Matt Novak, Jim Burge

Research output: Chapter in Book/Report/Conference proceedingConference contribution

15 Scopus citations


Flat mirrors of around 1 meter are efficiently manufactured with large piano polishers and measured with Fizeau interferometry. We have developed technologies and hardware that allow fabrication and testing of flat mirrors that are much larger. The grinding and polishing of the large surfaces uses conventional laps driven under computer control for accurate and systematic control of the surface figure. The measurements are provided by a combination of a scanning pentaprism test, capable of measuring power and low order irregularity over diameters up to 8 meters, and subaperture Fizeau interferometry. We have developed a vibration insensitive Fizeau interferometer with 1 meter aperture and software to optimally combine the data from the subaperture tests. These methods were proven on a 1.6 m flat mirror that was finished to 6 nm rms irregularity and 11 nm rms power.

Original languageEnglish (US)
Title of host publicationOptical Manufacturing and Testing VII
StatePublished - 2007
EventOptical Manufacturing and Testing VII - San Diego, CA, United States
Duration: Aug 28 2007Aug 29 2007

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherOptical Manufacturing and Testing VII
Country/TerritoryUnited States
CitySan Diego, CA


  • Large flat fabrication
  • Metrology
  • Optical manufacturing

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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