Accession Number : ADP006724

Title :   Phase-Coded Hologram Multiplexing for High Capacity Optical Data Storage,

Corporate Author : INSTITUT D'OPTIQUE THEORETIQUE ET APPLIQUEE PARIS (FRANCE)

Personal Author(s) : Denz, C. ; Pauliat, G. ; Roosen, G.

Report Date : 22 MAY 1992

Pagination or Media Count : 4

Abstract : Reconfigurable volume holograms are important for a wide range of multiple data storage applications, including optical interconnection systems, image processing and neural network models. Therefore, there has been much previous work on multiplexing techniques to obtain a large number of stored images which can be recalled independently. But even the most promising of these multiplexing techniques, angular multiplexing using the selectivity of the Bragg-condition, revealed to be limited primarily because of cross correlation noise. Moreover, mechanically changing the incident angle of the reference beam requires a high reliability in the positioning and is therefore inherently slow. To over-come these problems, an intensity spatial light modulator can be used to define the various angular multiplexed incident directions. However, this solution is energy consuming. Out of these reasons, we present in this paper an alternative approach implementing a phase coding method of the reference beam. Phase encoding has been discussed for interconnecting vector arrays in thin hologram and, more recently in a different context, to perform array interconnections by correlation of a reference beam with a supplementary phase-coded input beams.

Descriptors :   *HOLOGRAMS, *OPTICAL STORAGE, *REFRACTION, ANGLES, APPROACH, ARRAYS, CODING, CORRELATION, ENERGY, HIGH RELIABILITY, IMAGE PROCESSING, IMAGES, INPUT, INTENSITY, LIGHT, LIGHT MODULATORS, MODELS, MODULATORS, MULTIPLEXING, NETWORKS, NOISE, NUMBERS, PHASE, PROCESSING, RELIABILITY, STORAGE, VOLUME, DATA STORAGE SYSTEMS, OPTICAL IMAGES, ELECTROOPTICS, DIFFRACTION, SYMPOSIA.

Subject Categories : Optics
      Electrooptical and Optoelectronic Devices

Distribution Statement : APPROVED FOR PUBLIC RELEASE