Characterization of parasitic gratings in LiNbO3

We present a detailed experimental study of photoinduced light scattering in LiNbO3:Fe. The transmitted intensity was investigated as a function of the read-out wavelength and of the reconstruction angle for two different rotation axes. A simple phenomenological model based on the Ewald construction is developed which explains the characteristic features of the angular and spectral dependence of the transmitted intensity in the presence of parasitic gatings.