High-resolution inset head-mounted display.

A novel approach to inset superimposition in a high-resolution head-mounted display (HMD) is presented. The approach is innovative in its use of optoelectronic, nonmechanical devices in place of scanning mechanical devices commonly adopted previously. A paraxial layout of the overall HMD system is presented, and the benefit of employing hybrid refractive-diffractive optics for the optical component that generates the inset is discussed. A potential overall HMD design is finally presented to show the integrated system. The practical limitations of the designed system are discussed and an alternative approach is presented to compare the advantages and the limitations of these systems.

Efficient parallel algorithms for optical computing with the discrete Fourier transform (DFT) primitive.

Optical-computing technology offers new challenges to algorithm designers since it can perform an n-point discrete Fourier transform (DFT) computation in only unit time. Note that the DFT is a nontrivial computation in the parallel random-access machine model, a model of computing commonly used by parallel-algorithm designers. We develop two new models, the DFT-VLSIO (very-large-scale integrated optics) and the DFT-circuit, to capture this characteristic of optical computing. We also provide two paradigms for developing parallel algorithms in these models. Efficient parallel algorithms for many problems, including polynomial and matrix computations, sorting, and string matching, are presented. The sorting and string-matching algorithms are particularly noteworthy. Almost all these algorithms are within a polylog factor of the optical-computing (VLSIO) lower bounds derived by Barakat and Reif [Appl. Opt. 26, 1015 (1987) and by Tyagi and Reif [Proceedings of the Second IEEE Symposium on Parallel and Distributed Processing (Institute of Electrical and Electronics Engineers, New York, 1990) p. 14].

Optical expanders with applications in optical computing.

An optical system called the optical expander is described and investigated. The optical expander electro-optically expands an optical Boolean pattern encoded in d bits into an optical pattern of size N bits. It is assumed that d is equal to c log(2)N for some constant c, and each expanded pattern is orthogonal to the others. Two different architectures to implement the optical expander are described: one uses an optical matrix-vector multiplier and an array of N threshold devices; the other uses log(2)N novel reflection-transmission switching cells. These architectures are analyzed in terms of size, energy requirement, and speed. The optical expander described utilizes high-speed and high-space-bandwidth-product connections that are provided by optical beams in three dimensions. Potential applications, holographic memory, and message routing systems are also discussed.