Abstract

We present a theoretical and experimental investigation of a novel optical-disk memory. The system is designed to read data blocks that distributed radially on the disk's active surface. These data blocks are one-dimensional Fourier-transform computer-generated holograms, each reconstructing one column of a two-dimensional output image. Owing to the properties of Fourier transform holograms (information redundancy and shift invariance), no tracking or focusing servomechanisms are required. An area whose length is equal to an entire radial line of the disk's active surface is retrieved at once. In this way data are accessed through disk rotation only, with no mechanical motion of the head. Therefore, the entire disk content can be retrieved in a single rotation (25 ms), making this system very suitable for high-speed optoelectronic associative memory applications.

© 1990 Optical Society of America