Evaluation of holographic materials from applications point of view

The performance of a holographic product for commercial applications depends uniquely on the properties of the material and the skills of the manufacturer to best use and optimize these properties in the design stage and during the various manufacturing steps. The design of the HOE should take into account divers changes in the material that are caused by the process, such as swelling or shrinking of the holographic film, since these determine the spectral characteristics of the HOE. Often the changes are intentionally induced to achieve certain hologram properties, such as wavelength shift of the range of operation, the dependence of the diffraction efficiency on the reconstruction angle, or the desire to influence specific diffraction orders. We report here the results from the evaluation of the holographic properties of HOE in dichromated gelatin. These effects lead to the establishment of force fields and material diffusion throughout the depth of the holographic layer and create a gradient of the mean index of refraction that produces a shift in the angular spectrum. Experimental results for holograms fabricated in DCG and carboxylic polyvinyl alcohol (cPVA) are present and discussed. We report on the development and completion of a facility for continuous layer deposition on plastic substrate, hologram exposure and development.