By Topic

Micro, IEEE

Issue 6 • Date Dec. 1994

Filter Results

Displaying Results 1 - 6 of 6
  • Developing diffractive optics for optical computing

    Page(s): 10 - 19
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1259 KB)  

    Diffractive optical elements easily handle tasks such as the generation of uniform arrays of beams, beam steering and focusing, and aberration correction that conventional optics alone often find difficult or impossible. Here we review the design, fabrication, and performance of DOEs for use as free-space interconnection elements in optical-computing and photonic-switching applications. Our discussion focuses on Fourier- and Fresnel-regime surface-relief structures and their microlithographic fabrication. We include two practical examples to demonstrate the potential of such optical elements.<> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Developing a parallel-readout optical-disk system

    Page(s): 20 - 27
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (814 KB)  

    Optical-disk technology offers high storage densities with the possibility of parallel readout. Simply by illuminating a disk area containing more than one bit and appropriately encoding the bits, this technology permits retrieval of multiple data in parallel. When used in conjunction with a custom-designed parallel optoelectronic processing system, such systems meet the front-end storage and processing requirements for parallel-computing applications. The content-addressable memory system we are developing should prove useful for future very large database systems.<> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optical neural chips

    Page(s): 29 - 41
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1852 KB)  

    An array of photodetectors, each having a variable sensitivity, forms the most important component of our two gallium arsenide chips. We designed the optical neurochip so that variable sensitivity photodiodes are monolithically integrated on top of an LED array, serving both as fast analog multipliers and as on-chip weight storage elements with learning capability. Our artificial retina device combines a VSPD array with a neural network for postprocessing, allowing us to perform fast, yet flexible, processing operations on projected images.<> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optical correlators for space applications: prospects and problems

    Page(s): 42 - 47
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (709 KB)  

    Demanding ever-increasing throughput and processing power, space applications push the outer limits of conventional pattern-recognition technology. Optical correlators offer a siren's song of potential advantages over all-electronic devices. Realizing these advantages, however, will be difficult because of limitations on current spatial light modulators, key elements in an optical correlator. We propose a promising architecture that may overcome these limitations.<> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Using optical space-frequency analysis for real-time pattern recognition

    Page(s): 49 - 60
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2072 KB)  

    Simple, economical hardware based on incoherent space-frequency analysis overcomes many drawbacks associated with coherent optical systems. We have adopted this technique in developing a compact camera unit that uses a liquid-crystal light modulator for data input. This optically addressable camera system can automate a variety of visual inspection tasks. Adapted to conventional microscopes, it also enables automatic inspection of biological specimen textures, a useful tool in disease detection.<> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Hardware approaches to cache coherence in shared-memory multiprocessors. 2

    Page(s): 61 - 66
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1015 KB)  

    Improving performance and scalability in shared-memory multiprocessors requires an appropriate solution to the well-known cache coherence problem. Hardware schemes-highly convenient because of their transparency for software-offer fully dynamic solutions, with an ability to achieve high performance. In Part 1 of this two-part series, we discussed the principles of the two major groups of hardware protocols and summarized relevant representatives. Here, we also briefly consider the coherence problem in multilevel cache hierarchies and large-scale, shared-memory multiprocessors.<> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

High-quality technical articles from designers, systems integrators, and users discussing the design, performance, or application of microcomputer and microprocessor systems.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Erik R. Altman
School of Electrical and Computer Engineering
IBM T.J. Watson Research Center