Compact architecture for holographic systems

The holographic memory system we describe here integrates the various system components very closely to the crystal by using a smart pixel array and making use of phase-conjugate read-out to eliminate the need for imaging optics. This significantly reduces the alignment requirements and the number of required components. Our angularly multiplexed integrated read/write memory system is shown. An optoelectronic integrated circuit (OEIC) performing the functions of a spatial light modulator and a detector array is attached to the face of a 900-geometry photorefractive crystal perpendicular to the axis of the signal beam, while liquid crystal beam steerers are attached to the two adjacent faces that intersect the reference beam (the beam steerer behind the crystal is not visible in the figure). These beam steerers address the angularly multiplexed memory. Holograms are recorded by signal beam interference.