A multi-context programmable optically reconfigurable gate array without a beam splitter

Recently, optically reconfigurable gate arrays (ORGAs), which consist of a gate array VLSI, a holographic memory, and a laser array, have been developed to achieve a huge virtual gate count that is much larger than those of currently available VLSIs. Consequently, exploitation of the storage capacity of a holographic memory produces ORGAs with more than teragate capacity. However, comparison of conventional ORGAs with current field programmable gate arrays (FPGAs) reveals one important shortcoming: they are not reprogrammable after fabrication: to reprogram an ORGA, a holographic memory must be disassembled from its ORGA package, reprogrammed outside of the ORGA package using a holographic memory writer, and again implemented onto the ORGA package with high precision beyond the capability of manual assembly. Therefore, to remove that shortcoming, a programmable ORGA has been proposed. However, since previously proposed programmable ORGA configurations used a beam splitter, its alignment was complicated. Furthermore, the alignments of lasers were also limited. This paper presents a multi-context programmable optically reconfigurable gate array that uses no beam splitter. Furthermore, this paper presents discussions of the availability of this architecture and future plans based on experimental results.