Electric-field multiplexing/demultiplexing of volume holograms in photorefractive media

Electric-field multiplexing/demultiplexing of volume holograms in photorefractive media.

We propose a new method of volume hologram multiplexing/demultiplexing in noncentrosymmetric media. Volume holograms may be multiplexed by tuning the material parameters of the recording medium (such as refractive index or lattice parameters) while keeping the external parameters (wavelength and angles) fixed. For example, an external dc electric field alters the index of refraction through the...

Dark decay of holograms in photorefractive polymers

The decay of holograms stored in photorefractive polymer composites based on poly~N-vinyl-carbazole! with and without extrinsic deep traps is investigated. The photorefractive phase shift is identified as one of the key parameters determining the dark decay dynamics. This has important implications for all kinds of photorefractive imaging applications including holographic data storage. A trade...

Reduction in the reconstruction error of computer-generated holograms by photorefractive volume holography.

We suggest a method for coding high-resolution computer-generated volume holograms. It involves splitting the computer-generated hologram into multiple holograms, their individual recording as volume holograms by use of the maximal resolution available from the spatial light modulator, and subsequent simultaneous reconstruction. We demonstrate the recording and the reconstruction of a computer-...

Fixing of photorefractive volume holograms in K(1-y)Li(y)Ta(1-x)O(3).

We report the fixing of photorefractive holographic gratings with high efficiency in a sample of K(1-y)Li(y)Ta(1-x)Nb(x)O(3) doped with Cu, V, and Ti. Holograms are thermally fixed through the screening of a photorefractive space-charge f ield by a nonphotoactive species at elevated temperatures. Fixed holograms are revealed by illumination at lower temperatures. Diffraction efficiencies of 25%...

Volume Holograms