Surface profilometry by employing synthetic partially spatially coherent holograms

The aim of this work is to develop a holographic method that provides the shape reconstruction with an extended measurement range and preserved high accuracy. The method requires recording of series of fully-coherent holograms generated with varying tilt of plane wave illumination. The captured holograms are numerically processed to obtain the corresponding complex fields. The complex fields are used to produce a new set of holograms, which are used for calculating the longitudinal coherence function. This function allows observing fringes of high contrast at specific heights similar to white light interferometry, and thus, shape reconstruction of the three-dimensional object is carried out. The conclusions of this work are supported with results of numerical simulations.

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