Diffraction patterns for a transmission volume hologram under Bragg mismatch

We have presented simulations and experiments for 2-dimensional diffraction distributions of a transmission volume hologram. We sample the input patte rn with a few elementary points and calculate the diffraction of the corres ponding elementary grating. The simulations can describe well the diffracti on pattern obtained in the experiment and can be used to predict the tolera nce for angular deviation of the reading beam. The tolerance for angular de viation depends on its direction. It is affected by the Bragg degeneracy. T he simulation results provide a clear picture of the spatial tolerance for reading a transmission volume hologram.