We demonstrate a method of simultaneous holographic recording and readout in photorefractive crystals that provides high write-read beam isolation and wide angular bandwidth. The method uses orthogonally polarized read and write beams and parallel tangent diffraction geometry near the equal curvature condition to provide spatially separable, orthogonally polarized diffracted output beams with high isolation and wide Bragg-matched angular bandwidth. The available angular bandwidth of this read-write technique is analyzed, simulated, and experimentally investigated. The measured angular bandwidth internal to the crystal is approximately 18° × 6° for our 45°-cut BaTiO(3) crystal, yet the entire hologram still demonstrates high Bragg selectivity. In contrast, traditional nonparallel-tangent geometries yield angular apertures of the order of 1° × 4°.

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The promise of using volume holography to deliver high performance optical storage systems is at hand. The possibility of extremely large storage capacities and fast transfer rates make holographic storage ideal for high performance video applications. An overview of advances at InPhase Technologies is presented. Progress toward high-density implementations as well as the development of a functional prototype is presented. These systems are the first fully functional holographic recordable drives developed. Their development paves the way for the commercialization of this technology.

A high bandwidth, large degree-of-freedom photorefractive phased-array antenna beam-forming processor which uses three-dimensional dynamic volume holograms in photorefractive crystals to time integrate the adaptive weights to perform beam steering and jammer-cancellation signal-processing tasks is described. The processor calculates the angle-of-arrival of a desired signal of interest and steers the antenna pattern in the direction of this desired signal by forming a dynamic holographic grating proportional to the correlation between the incoming signal of interest from the antenna array and the temporal waveform of the desired signal. Experimental results of main-beam formation and measured array-functions are presented in addition to beam-propagation computer simulations demonstrating the spatio-temporal evolution of the holographic index grating and the resulting processor output. keywords: adaptive phased-array antennas, photorefractive signal processing, optoelectronic signal processing.

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