Formulation of off-axis single reference beam and two angle views for digital holography

Abstract

Photo-plates used in classical holography have several advantages, mainly a highresolution and the ability to overlap several holograms. Conversely, they sufferfrom chemical processing and delays in getting the useful signal. In contrast tofilm holography, digital holography offers quick and easy access to the desiredinformation but suffers from the low resolution of the CCD sensors and their smalldetecting areas. This is why many holographers were limited to the in-line scheme,because of its simplicity and ability to overcome this resolution problem. Butit still suffers from several problems when recording particles such as depth offocus, superposition of twin images and others. This is why, in spite of a morecomplex optical arrangement, we propose an appropriate off-axis scheme and atheoretical formulation that enables us to record simultaneously two hologramson the same CCD sensor from two angle views using a single reference beam.Furthermore, such a scheme, simpler than other off-axis proposals, provides spatiallyseparate reconstruction of the two views and overcomes the above cited problems. Asthe aim of our development is to measure the influence of concentration of solidparticles on their velocity for mixing flows, we show here examples without extendedanalysis.