Optical neural networks: an introduction to a special issue by the feature editors

This feature of Applied Optics is devoted to papers on the optical implementation of neural-network models of computation. Papers are included on optoelectronic neuron array devices, optical interconnection techniques using holograms and spatial light modulators, optical associative memories, demonstrations of optoelectronic systems for learning, classification, and target recognition, and on the demonstration, analysis, and simulation of adaptive interconnections for optical neural networks using photorefractive volume holograms

COMPUTER-GENERATED HOLOGRAM ETCHED IN GAAS FOR OPTICAL INTERCONNECTION OF VLSI CIRCUITS

By integrating, on a wafer plane, GaAs semiconductor optoelectronic modulators and detectors with computer-generated holograms between then, the potential for in-plane interconnections is proposed. We report the fabrication and characterisation of a binary-phase relief hologram etched in a GaAs wafer using an averaged Fresnel zone plate design to focus light to 2 x 2 spots for array interconnection. Efficiencies of 28% for this design of binary CGH etched in GaAs have been achieved, close to the theoretical maximum

An exploration of synchronization solutions for parallel short-range optical interconnect in mesochronous systems

As a result of the increasing complexity of electronic chips, the bandwidths required for inter- and intra-chip communication are rapidly increasing. As optoelectronics provides high=bandwidth and high-density interconnection it is considered as a candidate for short-range interconnection. For such interconnections, situated at a low level in the systems hierarchy, the interconnect latency is extremely critical for the systems performance. This paper describes some methods for mesochronous synchronization, needed for such interconnections. It will be shown that it can be beneficial to use an additional optical link to transfer a synchronization signal. Such a reference signal can be used efficiently for phase detection, provided that the data skew is sufficiently small, and result in a decrease of the cost-per-link

GaAs optoelectronic neuron arrays

A simple optoelectronic circuit integrated monolithically in GaAs to implement sigmoidal neuron responses is presented. The circuit integrates a light-emitting diode with one or two transistors and one or two photodetectors. The design considerations for building arrays with densities of up to 10^4 cm^-2 are discussed

Embedding of optical interconnections in flexible electronics

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Devices Having Compliant Wafer-level Input/output Interconnections And Packages Using Pillars And Methods Of Fabrication Thereof

Devices having one or more of the following: an input/output (I/O) interconnect system, an optical I/O interconnect, an electrical I/O interconnect, a radio frequency I/O interconnect, are disclosed. A representative I/O interconnect system includes a first substrate and a second substrate. The first substrate includes a compliant pillar vertically extending from the first substrate. The compliant pillar is constructed of a first material. The second substrate includes a compliant socket adapted to receive the compliant pillar. The compliant socket is constructed of a second material.Georgia Tech Research Corporatio