Parallel digital and symbolic optical computation via optical phase conjugation

Residue lookup table processor using an optical phase conjugation correlator

Described is a new optical residue lookup table (LUT) processor that is based on the residue LUT from an optical phase-conjugated correlation output of spatial position-encoded input vector patterns in a photorefractive BaTiO(3) correlator and a holographic mapping unit to group the same residue numbers. Some preliminary experimental results of these proposed techniques are presented and discussed.

Free-space optical collinear crossover interconnects

Two new optical free-space collinear cross-over interconnect schemes are suggested. The first optical implementation uses mirrors and beam splitters, while the second uses a Fresnel zone plate and lens combination. Some proof-of-principle experimental results are also presented.

Optical higher-order symbolic recognition

Several new higher-order spatial symbol recognition methods for optical symbolic substitution-based calculations are presented. In the case of logic processing, higher-order symbolic substitution (SS) rules can implement multivariable logic functions. For binary arithmetic calculations requiring carry propagation by simultaneously processing a number of bits, the computational speed increases. Finally, in image processing, the higher-order SS rules allow the use of larger local windows. For a higher-order spatial symbol recognition, both multiplicative and additive logic techniques are discussed. Four different higher-order SS recognition optical architectures are suggested: a multireflecting technique using an optical cavity, a lenslet array, an optical phase conjugation, and a content-addressable memory. Either dual-rail or triple-rail optical spatial intensity encoding is employed. Some preliminary experimental results are also presented.

Implementation of a binary optical full adder using a Venn diagram and optical phase conjugation

Conventional optical pattern logic schemes can only process two input variables at a time. We propose a new optical spatial encoding scheme that is capable of simultaneously processing multiple input variables. Based on this new scheme an optical full adder was experimentally demonstrated using a picosecond optical phase-conjugation device.