Multiplexed microholograms for optical data storage

An optical disk system has been proposed that stores the bit-formatted data in three dimensions as microscopic reflection holograms in a thin photosensitive layer. Each microhologram represents one bit. High storage densities can be achieved by combining multiplexing methods and multilayer storage. A theoretical model for microholographic gratings generated by two focused counterpropagating Gaussian beams predicts high values of diffraction efficiency, more than 95% for single microhologram. Physical principles of microholographic storage have been experimentally verified. This article reports on recording and characterization of microholograms in DuPont HRF-800 photopolymers.