Andrew Kostrzewski

Content-addressable-memory-based single-stage optical modified-signed-digit arithmetic

Using a novel nonholographic optoelectronic content-addressable memory in a free-space angular multiplexing geometry, a single-optical-stage compact parallel optical modified-signed-digit arithmetic processing architecture is proposed. Some spatial light modulator based 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.

Fast hybrid parallel carry look-ahead adder.

A new optical parallel arithmetic processing scheme using a nonholographic optoelectronic content-addressable memory (CAM) is discussed. The design of a four-bit CAM-based optical carry look-ahead adder (CLA) is presented. Compared with existing optoelectronic binary addition approaches, this nonholographic CAM scheme offers a number of practical advantages, such as faster processing speed and ease of optical implementation and alignment. For the addition of numbers longer than four bits, by incorporating the previous stages carry, a number of four-bit CLAs can be cascaded. Experimental results are also presented.

Free-space folded-path optical programmable logic array.

A new method to realize a medium-scale, free-space optical programmable logic array is proposed. By using either a two-dimensional optical spatial light modulator or an array of one-dimensional spatial light modulators inside a lens-based multiple-beam-path cavity, an array of optical multiple-variable logic product terms is generated. This device, together with a programmable multiple-variable OR matrix, can be used to implement any Boolean combinatorial logic operations. For an optical binary combinatorial logic computation, the proposed method efficiently uses three-dimensional space and optical elements. Preliminary experimental results obtained using an inexpensive liquid-crystal television are included.

Parallel optical pyramidal image processing

Pyramidal processing is a form of multiresolution image processing in which the image is decomposed into a sequence of images at different resolutions. Pyramidal processing aims to extract and interpret significant features of an image at different resolutions. Digital pyramidal image processing, because of the large number of convolution- type operations, is time consuming. On the other hand, optical pyramidal processors, described here, are preferable in real-time image-understanding applications because of their ease in performing convolution operations. Preliminary experimental results for optical Gaussian and Laplacian pyramidal image processing are presented.

Liquid crystal TV-based white light optical tracking novelty filter

A compact white light optical tracking novelty filter is demonstrated. Based on the use of two inexpensive liquid crystal televisions, a filtered and collimated white light source, digital delay, and video recorder, this portable white light device performs two major image comparison operations, a real time image subtraction and novelty tracking operations. Some preliminary experimental results are presented.

Optical position-coded multiple-valued logic and arithmetic using liquid-crystal TVs and holograms

Abstract An optical implementation of multiple-valued logic (MVL) operators that employs an optical holographic look-up table addressed by a pair of position-encoded liquid-crystal TVs is proposed. Realizations of optical modified signed-digit (MSD) as well as Post logic elements are included. Some first-order experimental results are presented.

Optical parallel register transfer microoperations using holographic symbolic substitutions

Optical register transfer microoperations are proposed. Based on an optical holographic associative symbolic substitution, a hybrid optical word-parallel bit-serial register transfer processor architecture is described. Preliminary experimental results are included.

Fast optical binary multiplication using a sign/logarithm number system

A new fast binary multiplication scheme based on a nonholographic optical content-addressable memory (CAM) is presented. By using a sign/logarithm number (SLN) system, the multiplication operation is performed through a binary logarithmic addition. A three-stage CAM-based multiplication scheme is proposed in which the first CAM converts input binary numbers to SLNs, the second CAM performs a fixed-point binary addition, and the third CAM converts this SLN result back to the binary number system. The design and experimental demonstration of a 7-bit nonholographic optoelectronic CAM-based multiplier are presented.

Real-Time White Light Pyramidal Tracking Novelty Filter

Optical temporal pyramidal image processing based on liquid-crystal televisions (LCTVs) and noncoherent illumination is proposed. compact non-coherent optical tracking novelty filter and its use as a temporal pyramidal filter are demonstrated. Some preliminary experimental results are presented.