DC term filtering techniques in digital holography

Abstract

In numerical hologram reconstruction like in optical holography, there exist different diffraction orders, which many times produce difficulties for the image visualizations. In numerical reconstruction, the filtering of the DC term, or zero order diffraction, provides an improved utilization of the dynamic range of the visualization systems, which is needed for the right displaying purposes of reconstructed images. In the case of the in-line set-ups, the zero diffraction order has even more devastating effects because it does not allow reconstructing the images itself as in Gabor's holograms, so it is necessary to attempt a filtering of this DC term. In this work is shown a qualitative assessment of different techniques of DC term filtering applied to numerical reconstruction of Fresnel's holograms recorded by means of off-line set-ups.