INTEGRATED OPTICAL HOLOGRAPHIC RANDOM ACCESS MEMORY WITH HIGH-DENSITY STORAGE AND HIGH-SPEED ACCESS

IN ORDER TO MEET THE NEED FOR SMALL, NON-MECHANICAL, HIGH CAPACITY, EXTREMELY HIGH ACCESS MEMORIES FOR INFORMATION HANDLING IN SUPER COMPUTERS, A NEW GENERATION OF VOLUME HOLOGRAPHIC STRUCTURES IS PROPOSED. WE NORMALLY THINK OF HIGH-INDEX-MODULATION HOLOGRAMS, SUCH AS DICHROMATED GELATIN, AS BING INHERENTLY THIN (LIMITED BY COATING, 1 CM) IS TO HAVE THE LIGHT ENTER AND LEVE THE HOLOGRAM ALONG ITS GRATING FRINGE PATTERNS. THEREFORE, THE COMBINATION OF HOLOGRAMS AND INTEGRATED OPTICAL WAVEGUIDES RESULTS IN A NEW APPROACH TO OBTAINING HIGH CAPACITY HIGH ACCESS OPTICAL MEMORIES IN COMPACT AND RUGGED MONOLITHIC PACKAGING. THIS APPROACH HAS THE FOLLOWING UNIQUE CHARACTERISTICS (NOT ACHIEVABLE BY ANY OTHER STATE-OF-THE-ART HOLOGRAMS): 1) VERY LARGE NUMBER OF BRAGG ANGULAR/WAVELENGTH MULTIPLEXED CHANNELS (>10(4)), 2) VERY HIGH INFORMATION STORAGE CAPACITY (>10(10) BITS PER WAVEGUIDE SUBSTITUTE), 3) INTEGRATION WITH MONOLITHIC MICROELECTRONIC/OPTOELECTRONIC COMPONENTS, AND 4) FAST ACCESS TIME (US\NS).