Mode theory of volume holograms allowing for nonlinearity of the photographic process

A mode theory is developed for image reconstruction by volume holograms allowing for nonlinearity of the photographic process. An analysis is made of cases of two possible types of reference wave: coded (i.e., with small-scale inhomogeneities) and plane. Expressions obtained for the diffraction efficiency can be used to study the spectral and angular selectivity, influence of shrinkage, polarization and other properties of volume holograms allowing for nonlinearity of the photographic process. Optimal intensities of the reference and object waves which can give the maximum diffraction efficiency are determined. The properties of superposed hologram recordings are investigated.