X-ray mirror metrology using SCOTS/deflectometry

Run Huang, Peng Su, James H. Burge, Mourad Idir

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

13 Scopus citations


SCOTS is a high precision slope measurement technology based on deflectometry. Light pattern on a LCD display illuminates the test surface and its reflected image is used to calculate the surface slope. SCOTS provides a high dynamic range full field measurement of the optics without null optics required. We report SCOTS tests on X-ray mirrors to nm and even sub nm level with precise calibration of the test system. A LCD screen with dots/check board pattern was aligned into the system at the test mirror position to calibrate camera imaging distortion in-situ. System errors were further eliminated by testing and subtracting a reference flat which was also aligned at the same position as the test mirror. A virtual reference based on the ideal shape of the test surface was calculated and subtracted from the test raw data. This makes the test a 'virtual null' test. Two X-ray mirrors were tested with SCOTS. 0.1μrad (rms) slope precision and sub nm (rms) surface accuracy were achieved.

Original languageEnglish (US)
Title of host publicationAdvances in X-Ray/EUV Optics and Components VIII
StatePublished - 2013
EventAdvances in X-Ray/EUV Optics and Components VIII - San Diego, CA, United States
Duration: Aug 26 2013Aug 28 2013

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherAdvances in X-Ray/EUV Optics and Components VIII
Country/TerritoryUnited States
CitySan Diego, CA


  • Optical metrology
  • X-ray optics

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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