Abstract
Two partially coherent and perpendicularly polarized vibrations induce, in a polarization sensitive photographic emulsion H, an anisotropy that is continuously varying across the plate. When the two incident amplitudes are assumed to be constant all over H, those variations are shown to be periodic functions of the effective phase shift φ. After exposure H is observed between crossed polarizers. It reconstructs an interferogram whose contrast is maximum whatever may be the degree of partial coherence and the relative amplitudes of the two vibrations. In plane rotation of the plate, H causes changes in the spatial frequency of the interferogram and localization of its dark fringes. When the direction of the polarizer is that of one of the original vibrations, the distance in terms of phase shift between any two consecutive dark fringes reaches π, and these fringes characterize the lines of equal phase φ = . Similar phenomena may be retrieved from that last setting by rotation of the analyzer initially crossed with the polarizer.