Classical holography experiments in digital terms

In this paper we present some classical holographic experiments only this time performed in various digital experimental arrangements. The information of the hologram is either calculated using discrete light diffraction formulae or recorded on a CCD, which takes the place of the registration holographic plate. The information of the hologram may be coded on a SLM which when illuminated reproduces the effects of the diffraction through the hologram or the diffraction may be calculated by a computer and so the output may be obtained more or less digitally. The distinction between virtual and actual digital is stressed. Experiments starting from the simple playback of computer generated Fourier holograms, going through basic interference experiments such as obtaining fringes of equal inclination up to more sophisticated configurations such as Fresnel holograms, are presented with a stress on the digital aspects that make these experiments depart from their classic counterpart.