As part of the development of an Experiment Container (EC) for the Fluid Science Laboratory (FSL), to be launched to the International Space Station, a digital holographic microscopy (DHM) system has been breadboarded. The scientific topic of this EC is emulsions, and a large depth of field (DOF) is required. The DHM enables to visualise the drops of emulsions, down to a size of 4 μm, on a DOF which is about 90 times its classical value. All this information is contained in one single image, which is a major advantage in space applications, where the downlink datarate and recording capacity are very limited compared to laboratory conditions. This paper describes the technique being used, presents the application to emulsions, shows tests results including image re-construction, and quantifies the performances as well as the limitations of the system.
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