Finite beams in large volume holograms

The properties of volume holograms are investigated for the special 2-dimensional case when the overlap of the inscribing beams is entirely in the interior of the holographic material. The amplitude distributions of the output beams and the power relations are derived on the basis of the model and formulas of Solymar. It is found that the amplitudes of the output beams become strongly varying for sufficiently high values of the coupling coefficient. It is further concluded that, for the beam geometry investigated, the distinction between transmission and reflection holograms is no longer relevant.