Digital holography and comparative digital holography are applications that require computer-addressable modulators for the optical reconstruction of digital holograms. The quality of the reconstructed holograms depends on the modulator's properties. Therefore a characterization of the modulators is required. We show the result of a modulator characterization and the modulator's influence on the quality of the reconstructed hologram. We then compare qualitatively and quantitatively the optical reconstruction of phase and amplitude holograms by considering their level of detail and their diffraction efficiency.

We report on first results obtained with two modified hologram optimization algorithms. These algorithms take into account the complex modulation characteristic of the spatial light modulators employed for hologram reconstruction. To this end the Jones matrices of the modulator as well as all other components of the setup are used within a modified direct binary search and an iterative Fourier transform algorithm. Geometrical phase effects are included in the optimization. Elimination of the analyzer behind the spatial light modulator is possible by that approach and for typical setups using twisted-nematic liquid crystal modulators an enhanced overall diffraction efficiency is achieved. Possible applications are the comparative digital holography and optical tweezers. Experimental results for the reconstructions of holograms with a Holoeye LC-R 3000 modulator are presented.

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This paper describes a new technique for modelling slope fringes in shearography using Fresnel wavefront propagation. Shearography is a full-field speckle interferometry technique usually used for displacement gradient and for shape measurement. One feature of shearography is that it uses a close to common path interferometer. This has the advantage of reducing sensitivity to environmental disturbances, but the disadvantage of a non-linear response. Previously one of the authors has used a ray tracing model of the fringe formation to improve the shape and slope measurement capabilities of shearography. The calculation involved was relatively time consuming as it required the calculation of the phase for each camera pixel individually. In this new Fresnel wavefront propagation model the approach is different. The system is modelled by propagation of the entire wavefront. This includes propagating the light through optical elements, such as a lens. This initial study has been for the formation of slope fringes in shearography using the source displacement technique. The advantages of this new technique are that it is easier to introduce optical elements and the effects of speckle noise into the simulation.

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