Many holographic techniques have been developed for non-destructive studies and characterization of materials. In this paper, discussion will be made about the employed holographic technique to characterize the poly(methyl methacrylate) (PMMA) matrices doped with azodyes. In this manner we were able to study the effect of the thickness of the samples, the effect of concentration of the ate-dyes and of PMMA and the effect of aging (storage time) on the holographic efficiency (diffraction efficiency) of these materials. Auto-erasable holographic gratings have been successfully recorded on ate-dye doped PMMA films and the dynamic diffraction efficiency was monitored with light different from that used for the recording.