Overmodulation effects in volume holograms recorded on photopolymers

Kogelnik's coupled-wave theory has provided a well established basis for understanding how light propagates inside a volume hologram and gives an accurate approximation of the diffraction efficiency in this type of hologram. In this paper we evaluate the effects of an overmodulation of the refractive index inside the hologram, which results in a particular behavior of the angular response of diffraction efficiency. These overmodulation effects are found in photopolymers with high acrylamide concentration. (C) 2002 Elsevier Science B.V. All rights reserved.