Appearance of conjugate images in a volume reflection hologram

A study is made of the mechanism of the appearance, in the radiation reconstructed from a volume reflection hologram, of not only the original object field but also of a field traveling in the opposite direction (conjugate object wave). This effect owes its origin to the interaction of fields with a complex angular aperture in the interior of a hologram and may ensure a relatively high efficiency of conversion into the conjugate wave. The calculations are made within the framework of the mode theory.