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In recent years there has been an increasing interest in holography and its applications. One such application is data
storage. Optimising the holographic recording materials is therefore of critical importance in the capacity and clarity
of the information stored. Photopolymer materials are practical materials for use as holographic recording media, as
they are inexpensive and self-processing. Understanding the photochemical mechanisms present during recording in
these materials is crucial in enabling further developments. Obtaining critical material parameters allows
improvements of the performance of these materials, such as its spatial frequency response or its environmental
stability. This also allows a better understanding of the photochemical processes that occur during the formation of
the holographic grating. Our current work, which is presented in this paper deals with two of the processes that
occur during holographic grating formation. The first of these is the photochemistry involved in the absorption of
the light by the photosensitive dye. We monitor the power of the transmitted beams, which are used for recording
the gratings. The second process we concentrate on is the inhibition effect present during grating growth. It has
been noted in the literature that there is a slight delay at the start of grating growth. The reason for this delay is due
to an inhibition process, which is present to some extent in all photopolymer recordings. The work presented here
explains why it occurs. A theoretical model is developed to predict the behaviour of the temporal evolution of the
grating. This model has been improved to account for the absorption effects of the material due to the photosensitive
dye and the inhibition period, which results in a reduction in the rate of polymerisation.
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