Dai Hyun Kim

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.

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.

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.

Ongoing applications of soft computing technologies to real-world problems at Physical Optics Corporation

Soft computing is a set of promising computational tools for solving problems that are inherently well solved by humans but not by standard computing means. This paper presents an overview of R and D activities at Physical Optics Corporation in the area of soft computing. The company has been involved in soft computing for over ten years, and has pioneered several soft-computing methodologies, including fuzzied genetic algorithms and neuro-fuzzy networks. Several practical implementations of soft computing are discussed.

Direct-view autostereoscopic monitor without goggles

Physical Optics Corporation has developed an autostereoscopic 3D display system that does not require viewers to wear goggles. This system is based on a stationary holographic projection diffuser fabricated using volume multiphase holographic optical elements. Design and development of the prototype are also described.

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.

Adaptive imaging system using image quality metric based on statistical analysis of speckle fields

This paper describes an Opto-Silicon Adaptive Imaging (OSAI) system capable of operating at low light intensities with high resolution, high accuracy, wide dynamic range, and high speed. The system consists of three major subsystems: (1) an adaptive imaging system in which a liquid crystal wavefront corrector measures image quality based on statistical analysis of a speckle field; (2) an image quality analyzer (IQA); (3) an opto-silicon multi-chip module combining a high-resolution ferroelectric liquid crystal SLM, CCD photodetector array, field-programmable gate array, and digital signal processor. The OSAI wavefront control applies adaptive optoelectronic feedback for iterative wavefront restoration and distortion compensation, suing an image quality metric based on statistical properties of the speckle field produced by moving a diffuser in the Fourier transform plane of a IQA optical system. A prototype IQA system was designed, manufactured, and tested using an input liquid crystal SLM, a Fourier lens, a light-shaping diffuser, and an output photodiode.

Soft computing and soft communications for synchronized data

In this paper a new algorithmic and hardware approach to real-time processing, computing, compression and transmission of multi-media (video, imagery, audio, sensor, telemetry, computer data) information, in the form of synchronized data, was proposed. The proposed approach, called Soft Computing and Soft Communication, leads to multi-media throughput minimization and data homogenization.

Application of genetic algorithms to autopiloting in aerial combat simulation

An autopilot algorithm that controls a fighter aircraft in simulated aerial combat is presented. A fitness function, whose arguments are the control settings of the simulated fighter, is continuously maximized by a fuzzied genetic algorithm. Results are presented for one-to-one combat simulated on a personal computer. Generalization to many-to-many combat is discussed.