Handheld non-contact evaluation of fastener flushness and countersink surface profiles using optical coherence tomography

James H. Wang, Michael Renxun Wang

Research output: Contribution to journalArticle

6 Scopus citations


We report the use of spectral domain optical coherence tomography (SD-OCT) for non-contact optical evaluation of fastener flushness and countersink surface profile. Using a handheld galvanometer scanner of only 0.5 lb in weight the SD-OCT can perform line scan surface profile measurement of fastener and countersink without demanding accurate scan center alignment. It demonstrates fast measurement of fastener flushness, radius, slant angle, as well as countersink edge radius and surface angle within 90 ms suitable for handheld operation. With the use of a broadband light source at 840 nm center wavelength and 45 nm spectral bandwidth and a lens of 60 mm focal length, the low coherence interferometry based SD-OCT measurement offers axial depth resolution of 8.5 μm, lateral resolution of 19 μm, and measurement depth of 3.65 mm in the air. Multi-line scans can yield 3D surface profiles of fastener and countersink.

Original languageEnglish (US)
Pages (from-to)206-212
Number of pages7
JournalOptics Communications
StatePublished - Jul 15 2016



  • Countersink
  • Fastener flushness
  • Optical coherence tomography
  • Optical imaging

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering
  • Atomic and Molecular Physics, and Optics
  • Physical and Theoretical Chemistry

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