Abstract

This paper reports the design and fabrication of a prototype holographic optical processor array—HOPE—for parallel optical logic, arithmetic and interconnect operations. The volume holographic technology gives the inherent advantages of high resolution, large dynamic range, large recording area, low cost and 3-D interconnection capabilities. A set of rules and input/output lookup tables can be recorded in a holographic associative memory, and then the HOPE performs parallel operations by input/output symbolic substitutions and thresholds. A practical N⁴ recording scheme has been developed to record a 2-D array of holographic elements. The automatic recording system is capable of constructing an array of up to 256 × 256 holograms on a 128 × 128 mm² holographic plate, each hologram 0.5 × 0.5 mm² in size. Based on large array of holographic elements, the HOPE has the potential of highly parallel computation between thousands of optical processors in a compact system. The aim of this research study is toward the concept design of a HOPE architecture with the electronic counterpart-connection machine in mind. A prototype HOPE system is designed and fabricated with moderate number of holographic elements (approximately 1000 holograms of 1 × 1 mm² in size) which employs commercially available devices such as high contrast liquid crystal television and CCD camera as input and output interface. Evaluation of the system performance is also discussed.

© 1991 Optical Society of America