z-logo
Premium
Measurement of Surface Shape and Position by Phase‐Shifting Digital Holography
Author(s) -
Yamaguchi I.,
Ida T.,
Yokota M.
Publication year - 2008
Publication title -
strain
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.477
H-Index - 47
eISSN - 1475-1305
pISSN - 0039-2103
DOI - 10.1111/j.1475-1305.2008.00454.x
Subject(s) - optics , position (finance) , holography , digital holography , speckle pattern , phase (matter) , interferometry , physics , holographic interferometry , amplitude , digital holographic microscopy , coherence (philosophical gambling strategy) , speckle noise , superposition principle , wavelength , economics , finance , quantum mechanics
  Phase‐shifting digital holography is applied to measure the shapes and positions of rough surfaces from the averaged conjugate product of the reconstructed complex amplitudes, named complex coherence factor, corresponding to dual wavelengths. The phase of the averaged product at the object plane provides the shape of the surface, whereas the peak position of the modulus with respect to reconstruction distance provides the position of the surface. The phase is almost free from speckle noise and easy to be unwrapped. The resultant resolution of surface shape amounts to a few tens of micrometres. The sensitivity of the position measurement that requires no marking on the object is several per cent of object distance from a charge‐coupled device (CCD). The method corresponds to the detection of the position of maximum contrast of the fringes to be observed in conventional holographic interferometry. It makes use of fringe phase for shape measurement and fringe contrast for position measurement. Both the theory explaining the principle and experimental results are presented.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here