Our previous investigation regarding liquid crystal mixtures, used as a medium for dynamic holography, has proved the influence of addition of PVK (polivinylocarbazol) layer to the LC cell structure as a sensitivity amplifier . This modification was very useful for bettering the dynamic properties of these modulators. In some cases (of LC Cells) we observe some kind of memory effect - holograms written before could be observed months after writing. We decided to examine different cells to determine CL Cell construction as rewritable holographic media.
Dynamic optical data storage and other applications in the field of optical data processing would be enabled by the development of suitable nonlinear optical materials. In this paper we present an experimental investigation of the orientation photorefractive effect in nematic liquid crystal mixtures with different optical anisotropy and various cell construction layers.
The possibility of diffraction pattern generation in LC (Liquid Crystal) cells working as a dynamic write-read media was proven. Recording of holographic gratings formed by interfered He-Ne laser beams onto LC-cells with pure and dye-doped mixture have been investigated. The possibility of optoelectronic reconstruction of digitally stored microinterferograms allow us to adopt them in multimedia application. The hologram of virtual or real object was reconstructed by coherent illumination of optically addressed spatial light modulator (OASLM) containing holographic grating. The results obtained from LC cells of standard twisted nematic type were examined. As a result of examination of physical properties of nematic-type liquid crystal mixtures, new method of realization of LC cells were proposed. The experimental results of replacing TN cells with polivinylcarbazole (PVK) photosensitive layer cells have been discussed.
In this paper relation between the diffraction efficiency in LC dye doped cell in two wave mixing system and the applied voltage parameters had been described. The goal of this work was increase of diffraction efficiency using low frequency AC voltage. The LC cells used in the experiments were filled with pure and dye-doped liquid crystal mixtures. In this system we obtained diffraction efficiency increasing about five to eight times.