A general two‐dimensional theory for volume holograms

Coupled partial differential equations are derived for the amplitude of the electric field in a general two‐dimensional volume hologram. Nonuniform amplitude distributions, nonplanar wave fronts, losses, and non‐Bragg incidence are considered both for dielectric and absorption gratings. The formulation is in holographic terminology but the equations are valid for weakly modulated Bragg devices in general.