Synthesis of moving holographic stereograms with high-resolution spatial light modulators

Displaying animated holographic 3D image by means of opto-electronic devices causes serious problems because of the huge amount of data in the hologram and the inadequate resolution of the display. One possible solution is to limit the reconstructed 3D image to discrete horizontal perspectives. In this paper, a 3D display is proposed which permits the creation of holographic stereograms with novel high-resolution diffraction light modulators. The modulators perform the image generation and the direction-selective display of 2D perspective views simultaneously in the same way as holographic stereograms. The modulators are based on optically defined binary phase gratings with diffraction properties that are altered by an LC layer. Switchable gratings with periods down to 1 mu m and with high diffraction efficiencies and extinction ratios have been demonstrated. Until now the hologram synthesis itself could not be accomplished because of the lack of a sufficiently large electronic addressing matrix, but the basic modulator principle, underlying the synthesizer has been demonstrated experimentally. We explain the optoelectronic hologram synthesizer scheme, the diffraction light modulator construction and the diffraction properties achieved by the modulators we have fabricated.