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Collins, S. A., Jr.

Publications and source records attributed to Collins, S. A., Jr..

8 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Optical computer switching network

The design for an optical switching system for minicomputers that uses an optical spatial light modulator such as a Hughes liquid crystal light valve is presented. The switching system is designed to connect 80 minicomputers coupled to the switching system by optical fibers. The system has two major parts: the connection system that connects the data lines by which the computers communicate via a two-dimensional optical matrix array and the control system that controls which computers are connected. The basic system, the matrix-based connecting system, and some of the optical components to be used are described. Finally, the details of the control system are given and illustrated with a discussion of timing.

Clymer, B.↗
NASA NTRS1984

Optical flip-flops and sequential logic circuits using a liquid crystal light valve

This paper is concerned with the application of optics to digital computing. A Hughes liquid crystal light valve is used as an active optical element where a weak light beam can control a strong light beam with either a positive or negative gain characteristic. With this device as the central element the ability to produce bistable states from which different types of flip-flop can be implemented is demonstrated. In this paper, some general comments are first presented on digital computing as applied to optics. This is followed by a discussion of optical implementation of various types of flip-flop. These flip-flops are then used in the design of optical equivalents to a few simple sequential circuits such as shift registers and accumulators. As a typical sequential machine, a schematic layout for an optical binary temporal integrator is presented. Finally, a suggested experimental configuration for an optical master-slave flip-flop array is given.

Fatehi, M. T.↗
NASA NTRS1984

Optical pulse generator using liquid crystal light valve

Numerical optical computing is discussed. A design for an optical pulse generator using a Hughes Liquid crystal light valve and intended for application as an optical clock in a numerical optical computer is considered. The pulse generator is similar in concept to the familiar electronic multivibrator, having a flip-flop and delay units.

Collins, S. A., Jr.↗
NASA NTRS1984

Optical residue addition and storage units using a Hughes liquid crystal light valve

Optical addition and storage units are described in this paper. These units are implemented using the Hughes Liquid Crystal Light Valve (LCLV) as a spatial light modulator using residue arithmetic for a numerical representation. The main hardware components of the design, besides the light valve, include an array of single-mode optical fibers that provide input information, a polarizing prism in combination with quarter-wave and half-wave retarders for residue arithmetic implementation in the adder, and a holographic array for spatial stability in the storage unit.

Habiby, S. F.↗
NASA NTRS1972

Grand Tour outer planet missions definition phase. Part 2: Minutes of meetings and official correspondence

A variety of imaging systems proposed for use aboard the Outer Planet Grand Tour Explorer are discussed and evaluated in terms of optimal resolution capability and efficient time utilization. It is pointed out that the planetary and satellite alignments at the time of encounter dictate a high degree of adaptability and versatility in order to provide sufficient image enhancement over earth-based techniques. Data compression methods are also evaluated according to the same criteria.

Belton, M. J. S.↗
NASA NTRS1971

The Mariner 6 and 7 pictures of Mars

A comprehensive set of high quality reproductions of the final, computer-processed television pictures of Mars is presented. The genesis and unique characteristics of the pictures are explained, interesting features are pointed out, and some indication of their significance in the history of Mars investigations is provided.

Collins, S. A., Jr.↗