PHASE-DETECTION WAVELENGTH-SCANNING INTERFEROMETRY

• Abstract:

  We have realized an accurate height measurement for discontinuous shape by using the wavelength scanning interferometry combined with phase-shifting technique. It is based on detection of phase variation slope along the wavenumber axis at each pixel of a CCD camera that takes a number of phase-shifted interferograms using a PZT mirror. By using a tunable laser diode with wavelengthscanning range of 8 nm and scanning step of 0.2 nm, a height standard deviation of 40 nm could be obtained for the depth of ± 0.75 mm. This technique was applied to profile measurements of an aspherical mirror and rough-surface objects.
• Keywords:

  wavelength-scanning interferometry, phase analysis, profilometry
• Download:

  IMEKO-WC-2000-TC14-P377.pdf
• DOI:

  _unreg_wc-2000.377

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