Digital Holography is applied to make micro-displacements determination of a steel bar and an aluminum sheet. The displacement of aluminum sheet is made under immersion conditions in water and air. An experimental installation is presented for digital holograms registration with plane reference beam, using a CCD camera as detector. The "HOLODIG" computing system was developed for digital reconstruction of the image using the direct method, the intensity and phase image and interferograms were obtained. Taking into account the phase interferogram and making the unwrapping, the phase was determined for every point of the study surface. As examples of method application the displacement of a square section steel bar, tested in air, and an aluminum sheet, tested in air and submerged in water, were determined. Experimental values of the displacement obtained agree with the applied ones. In the case of aluminum plate submerged in water, the magnitude of the measured displacement is proportional to water refraction index.
Using digital holography the two-source method was applied for shape determination of a groove on an Aluminum plate. The electric component of the electromagnetic field, on the image plane, was reconstructed using the Fresnel-Kirchoff integral and Fourier method and digital holograms were captured changing the fiber optic position with a micro positioner. The phase interferogram was filtered by means of the sine/cosine filter and for the unwrapping process was applied the branch-cut method. This object present real discontinuity and the experimental results agree with the expected one, with high quality intensity image. The quasi-3D phase presentation shows the object shape.
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