bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical Implementation of Association and Learning Based on Primo/Light Valve Devices
Authors: Efron U. , Owechko Y.
Published: February 2023

The effort proposed here is aimed at demonstrating the use of existing optical and electrooptical components in implementing adaptive neural network systems. Specifically, we propose a system which implements the outer product model(1,2) of auto- or hetero-association. Both learning and association operation can be executed using this system which is based on the use of 1-D striped-electrode fast input modulators (based on the PRIMO technology(3)) coupled with a time integrating photoactivated liquid crystal light valve.
The Thermal Nonlinear Microcavity and Optical Computing
Authors: Godsalve C. , Abraham E.
Published: February 2023

Thin film Fabry-Perot etalons which have a temperature dependent refractive index exhibit bistability or gain at room temperature (e.g. ZnSe) and at optical frequencies. These features make them candidates for digital optical computing. An N x N array of elements can be generated in a single filter by an array of laser beams. As a result, thermal crosstalk develops which is long range and only a few elements per cm2 on such a filter can operate independently [1,2]. However if each filter is mounted on its own separate 'turret', crosstalk can be reduced to the extent that 104 microcavities (or pixels) can operate independently per cm2 [3,4].
Hybrid Optical Processing for Measuring the Refractive Index Profile in Single-Mode Fibers
Authors: Nobuyoshi T.
Published: February 2023

In estimation of propagation characteristics for singlemode fibers, the refractive index profile plays an important role. Several measurement methods such as the exit radiation pattern method (ERP)[1] and the near field intensity method (NFI)[2] have been recently developed with a relatively high spatial resolution. Both methods, however, require complicated features: cumbersome computation, with inverse Hankel transformation and correction of dynamic range in the case of ERP; numerical derivations and smoothing for noise reduction in the case of NFI. In this study, we present a new processing technique for calculation of the refractive index profile in single-mode fibers. This technique makes use of hybrid optical processing with a spatial filter (a radially inhomogeneous transparent filter) and two lenses, creating the Hankel transformation and the inverse transformation. This method allows real time monitoring of the profile and permits significantly less computational time as compared to that of conventional computer methods.
On the Hardware Requirement for 2-D Image Convolution in Electro-Optical Systems1
Authors: Eshaghian M. Mary , Panda D. K. , Prasanna Kumar V. K.
Published: February 2023

The computational throughput of a parallel architecture is largely dependent on it’s communication bandwidth. The communication bandwidth available in the present day parallel systems is reaching saturation due to the inherent limitations of transmitting electronic signals. To overcome this problem, researchers have considered contention-free optical beams as an efficient means of interconnection [GLKA84,JS87], Unlike the electronic signal, the optical interconnection offers dual advantages of larger bandwidth and fan-out. With the availability of such interconnection the field of Optical computing is being diversified from the development of analog optical process sors [CRFH81] to digital optical and electro-optical computers [Hua84,EK88], Such electro-optical systems, capable of exploiting the speed and parallelism of optical systems together with the programmability and accuracy of electronic computers, promise tremendous computational power.
Computer Holographic Elements Using PostScript Laser Printers
Authors: Domash Lawrence , Levin Philip
Published: February 2023

Computer generated holograms and diffractive optical elements are desired for a wide range of applications including optical interconnects, pattern recognition filters, binary phase filters, laser beam combiners, and displays. However, methods to design and produce them have been cumbersome. Typically, software been written anew for each application in Fortran on large computers and used to address e-beam lithography devices (1). This process results in submicron resolution but is slow, inflexible and costly. Only recently have efforts begun to bring to diffractive optics the highly developed computer aided design tools available for other engineering disciplines (2). Research and practical applications of diffractive/holographic elements of all kinds would be accelerated if there existed a simple, quick, low cost and easy to use method for creating optical patterns even of moderate resolution (1-3 microns).
Using symbolic substitution method on optical matrix multiplication
Authors: Chin Kuo-fan , Wu Minxian , Zhou Shaomin
Published: February 2023

The optical matrix computing often plays a very important role in optical digital processing, many transformation and information processings in optics can be converted into a group of basic matrix multiplications1. Now, many approaches to implement such calculations have been provided2-4. But to all the existed schemes and systems, the difficulty is the long time sequence and the lower accuracy obtained, as well as a rather complicated system is required. In this paper, we have tried to use optical symbolic substitution method5 combined with the calculation of outer product of matrices to solve the multiplication of matrices. Preliminary experimental result has been obtained successively.
Intelligent Optical Processors
Authors: Ghosh Anjan
Published: February 2023

The accuracy of matrix computations performed on high-speed analog optical associative processors (OAPs) is limited by the noise and spatial errors. There exist two different approaches for alleviating this limitation: (i) postprocessing with a bimodal system [1] and (ii) preprocessing with a preconditioner [2,3]. In this talk we show that these two approaches can be combined to develop an "intelligent" optical processor that can adapt the computational steps depending on the data and produce accurate solutions at a high speed.
Reconfigurable Programmable Optical Digital Computer
Authors: Guilfoyle P.S. , Zeise E E
Published: February 2023

Previous optical computing schemes offered analog or quasi-digital accuracies with a single fixed primitive. This paper describes how programmable, arbitrary bit length all digital Central ProcessingUnit (CPU) computations are now possible. In addition, the current state-of-the-art in optical computer subsystem devices such as acousto-optic modulators, detector and source arrays, posture this architecture as a revolutionary technology in and of itself, as it may be applied to an implementation plethora.
An Optical Programmable Binary Symmetric Logic Module
Authors: Li Yao , Ha Berlin , Eichmann George
Published: February 2023

Binary symmetric logic function (BSLF)1, because of its invariance under the permutation of its input variables, is an important class of Boolean logic function. The diversified BSLF applications include the synthesis of binary full adder and subtractor, the binary text comparator, the median filter, the parity checker, various threshold elements, eta.. The classical BSLF realization uses an array of regularly interconnected slow-speed electric contact network. Optical switches, because of their pico-or femtosecond switching capability, are excellent candidates for an optical BSLF (OBSLF) implementation. In this paper, various OBSLF architectures together with their applications to optical digital and symbolic computing, data communication, image processing, as well as neural networks, are described.
Optical realization of arithmetic operations in ternary number system
Authors: Dianov E.M. , Kuznetsov A.A. , Nefjodov S.M. , Voevodkin G.G.
Published: February 2023

The main advantage of the ternary number system over the other ones is its the promise of higher efficiency.
An Electro-Optical Architecture for Solving General Sparse Linear Systems1
Authors: Eshaghian M. Mary , Prasanna Kumar V. K. , Tang David W.
Published: February 2023

Many engineering problems involve the solution of a set of linear equations at some stage in the analysis. Many of these problems can be characterized by sparsity, that is the associated coefficient matrix contains a large proportion of zero elements. Examples include electric power system analysis, structural analysis, image processing, etc [1].
Progress in Arrays of Opto-Electronic Bistable Devices and Sources
Authors: Kasahara K. , Ogura I. , Yamanaka Y.
Published: February 2023

With recent progress in semiconductor arrays of opto-electronic bistable devices and sources, highly parallel optical interconnections and information processing has gradually become a reality. The Vertical to Surface Transmission Electro-Photonic device, or VSTEP, is a concept proposed to meet these requirements1). The essential ideas for the VSTEP are electrophotonic interfusion at the device level and the resulting performance efficiency improvements in power consumption and uniformity for two-dimensional matrix integration.
Integrated Free Space-Optical Permutation Network
Authors: Jahns Jürgen , Däschner Walter
Published: February 2023

Permutation networks such as the Perfect Shuffle, the Banyan, and the Crossover network can be used in optical computing or photonic switching to implement parallel algorithms efficiently [1]. Many different implementations for these various networks have been proposed recently; see for example [2-4]. A very flexible way of implementing space-variant permutation networks is by using diffracitve lenslet arrays [5, 6]. The basic concept is to give each optical channel its own miniaturized optical system, consisting typically of two diffractive off-axis lenslets. By controling the angle under which the light beams travel, it is possible to realize arbitrary interconnect schemes. The optical setup for this is shown in Figure 1. Using lithographic techniques, all components in an array can be fabricated at the same time with high alignment precision. In order to achieve high efficiencies diffractive optical elements can be implemented as phase structures with multiple discrete phase levels [7, 8]. A 2-D cyclic shifter was demonstrated recently using lithographically fabricated lenslet arrays [9]. An experimental result is shown in Fig. 2.
Cellular Hypercube Interconnections for Optical Processor Arrays
Authors: Kuznia C. B. , Sawchuk A. A.
Published: February 2023

Digital optical cellular arrays are single-instruction-multiple-data (SIMD) arrays of many low complexity (fine-grain) processing elements (PEs). The PEs themselves can be implemented by electronic or optoelectronic methods. These arrays have many general applications in numerical processing and symbolic substitution computing. They are particularly suited to bit plane images (images in which each PE represents a pixel, and each pixel takes on the value 0 or 1). In this application, each PE is referred to as a cell and is responsible for computing the output of one image pixel according to a single instruction broadcast to all PEs from a central control unit.
Some practical issues associated with the design and fabrication of high contrast quantum well modulator arrays
Authors: Parry G , Whitehead M , Zouganeli P , Rivers A , Woodbridge K , Roberts J S , Button C
Published: February 2023

Asymmetric Fabry-Perot modulators offer the prospect of high contrast (>20dB) and low voltage (<5V) operation as well as useful optical bandwidths. This paper discusses some of the practical problems of designing and fabricating arrays of devices to meet these specifications.
An Optical Processing Unit for Relational Database Operations
Authors: Mitkas Pericles A. , Berra P. Bruce
Published: February 2023

The management of very large databases (order of hundreds of gigabytes), combined with the real-time response requirement, poses a formidable task even for today's powerful computers. Special-purpose computers dedicated to database management, known as database machines, must provide adequate secondary storage to accommodate the database, high transfer rates to the processing units, and a large degree of parallelism.
Fault-Tolerant Computing on POEM
Authors: Lu Dau-Tsuong , Lin Ting-Ting Y. , Kiamilev Fouad E. , Esener Sadik C. , Lee Sing H.
Published: February 2023

Wafer scale integration (WSI) promises to realize a complete multiprocessing system on the same wafer and eliminates the expensive steps required to dice and bond. The fundamental belief is that the internal connection between chips on the same wafer are more reliable and have a smaller propagation delay than external connections1. However, achieving a high yield has proven to be a major challenge. Rather than aiming for 100% yield, the realistic solution is to determine the defective components on the wafer and replace them with spares. Which means, the design should be tolerant to faults developed during the manufacturing process. Moreover, faults occur during system operation, be it component failure, improper operation, or environmental factors. Therefore, a mean to detect these unexpected faults and recover from them is necessary to minimize down time and unavailability. Long and periodic system downs are a luxury that cannot be afforded for computers used in critical applications. In this paper, we show that the introduction of optical interconnection techniques into a multiprocessor environment (e.g. the Programmable Optoelectronic Multiprocessor, POEM) enables efficient implementation of fault-tolerant techniques.
Fanout Analysis of a Low-Skew Clock Distribution Network with Optical Amplifiers
Authors: Li C.-S. , Tong F. , Messerschmitt D. G.
Published: February 2023

Optimization of the performance of a high­speed synchronous digital system requires tight control of the timing skew within a clock distribution network (CDN). Techniques for distributing the optical clock signals in a single-stage CDN have been suggested in [1,2] to reduce the timing skew, and the fanout is found to be much larger than that obtained from an electronic CDN. In this paper, we investigate the enhancement of fanout when optical amplifiers, which could either be semiconductor laser amplifiers [3] or fiber amplifiers [4], are introduced in a CDN.
Reconfigurable Interconnects Using Computer Generated Holograms and Spatial Light Modulators
Authors: Morris James E. , Feldman Michael R.
Published: February 2023

An efficient method of implementing programmable optical interconnects is needed for communication between processors in optically interconnected VLSI processor arrays[1,2], between optical logic gates in optical computers[3], and between chips, modules and boards in general purpose VLSI systems[4-6].
Enhanced photorefractive effects with a de field and moving grating in GaP at 633 nm
Authors: Ma Jian , Taketomi Yoshinao , Fainman Yeshaiahu , Ford Joseph E. , Lee Sing H. , Chino Ken’ichi
Published: February 2023

Photorefractive (PR) devices have found applications in optical computing, image processing and pattern recognition[1–3], because PR materials provide unique features such as real time operation, optical gain, storage, nonlinear operations, phase conjugation and correlation. New PR materials are being investigated in order to meet the device and system requirements of sensitivity, speed, and operation wavelength (e.g., response to the near infrared spectral range for systems operated with semiconductor lasers). Compound semiconductors may satisfy these requirements. For example, optical signal amplification by two-beam coupling and amplified phase-conjugate beam reflection by four-wave mixing have been reported in GaAs[4] and InP[5] at the wavelength of 1.06 μm. Recently, GaP[6–7] was shown to possess a relatively weak PR effect in the spectral range of 0.6 to 0.9 μm. In this manuscript we report enhancement of the PR effect in GaP using an externally applied electric field and moving grating. In particular, two- and four-wave mixing experiments were used to demonstrate a gain coefficient of Γ = 1.9 cm–1 and a phase conjugate reflectivity, R= 4.5%. In addition, several figures of merit of GaP, i.e., steady-state index change, absorption coefficient, response time and PR sensitivity were characterized.
A polarization metrology for optical interconnects which use polarization beam combining
Authors: Pezzaniti J. Larry , Chipman Russell A.
Published: February 2023

Several free space optical interconnects for digital optical computing which use polarization beam combining are currently being implemented 1-5 These architectures interconnect 2-D arrays of optical logic devices by imaging arrays of spots, generated by binary phase gratings, from one logic device to the next. Polarization beam combining addresses the need to combine input beams and separate output beams by using space-variant mirrors in conjunction with polarizing beam splitters and waveplates. The throughput of the interconnect is limited primarily by the polarizing beam splitters and the waveplates.
Digital Approach for Pattern Scale Measurement
Authors: Rosen Joseph , Dezialoshinski Lior , Nahtomi Ehud , Shamir Joseph
Published: February 2023

Pattern size measurement is important for applications such as industrial classification and ranging. Optical systems offer fast and parallel processing of detailed pictures.
Multichannel Bragg Cells for Optical Computing Applications
Authors: Pape Dennis R.
Published: February 2023

Acousto-optic Bragg cell devices currently provide the most effective way of imparting electrical information in real-time onto a light beam. Multichannel Bragg cells, with individually addressable electrodes on the same transducer substrate, extend the power of optical processing in a compact package to optical computing applications such as twodimensional optical switching and matrix-vector processing. The design of the cell, with the placement of multiple electrodes in close proximity on a common acoustic substrate, is constrained by crosstalk and thermal requirements not found in the design of a single-channel device. These constraints arise from the desire to place the electrodes as close as possible to maximize spatial duty cycle without creating unacceptable adjacent channel crosstalk and optical beam distortion. In this paper we discuss multichannel Bragg cell design principles and the use of RF stripline techniques and acoustically anisotropic acousto-optic materials with high thermal conductivity to achieve high multichannel cell performance. We describe several high performance Gallium Phosphide multichannel Bragg cells which employ these design techniques. We contrast the performance of these cells with devices manufactured commercially in the United States as well in the Soviet Union. Finally, optical computing systems using multichannel Bragg cells for switching and processing are discussed.
Design and Construction of a Programmable Optical 16x16 Array Processor
Authors: Walker A.C. , Craig R.G.A. , McKnight D.J. , Redmond I.R. , Snowdon J.F. , Buller G.S. , Restali E.J. , Wilson R.A. , Wakelin S. , McArdle N. , Meredith P. , Miller J.M. , MacKinnon G. , Taghizadeh M.R. , Smith S.D. , Wherrett B.S.
Published: February 2023

There have been a number of significant advances in digital optical computing research over recent years. Experimental demonstrations of optical restoring logic1, the lock-and clock control of data flow2, a programmable optical logic unit3, optical switching networks4, and parallel logic modules5 have shown that the basic building blocks for a parallel digital optical computing system now exist. This paper describes recent work carried out at Heriot-Watt University in which such a demonstration optical processor has been constructed.
Cellular Automatæ via Multi-Kernel Incoherent Holographic Convolution
Authors: Glaser I.
Published: February 2023

Cellular machines [1,2,3,4] are two dimensional arrays of rather primitive processing elements (PE-s) that are controlled by the internal state of their neighborhood PE-s and (usually) by some external instruction stream in a SIMD style. Such machines offer high computational speed for a useful class of problems, particularly in image processing. While some cellular machines were implemented in silicon, newer versions with enhanced connectivity, such as the cellular hypercube [5], are probably too complex for electronics. Furthermore, the ‘almost-shift-invariant’ geometry of cellular machine interconnections is a good match to optical convolution, which is easy to carried out.
Optical Database Machines
Authors: Berra P. Bruce
Published: February 2023

Databases have become an important aspect of our daily lives. We encounter them in such diverse fields as airline reservations, stock quotation systems, medical information systems, entertainment, sports and a host of other areas. Database management systems (DBMS) place considerable demands on current computing systems primarily because of the large size of the databases, the general functionality of the DBMS and the stringent time requirements for the retrieval of the data. The large size of the database dictates that secondary storage such as optical and magnetic disks be used and this leads to input/output data accessing difficulties since these memory types are on the order of one million times slower in access time than main memory technology. The diverse functionality of DBMS leads to systems with millions of lines of code that consume an enormous number of machine cycles. Add to this the near real time requirement for many applications and one has a system that is both I/O and compute bound.
A 4×4 Photorefractive Reconfigurable Interconnect Using Laser Diodes
Authors: Chiou Arthur E. , Yeh Pochi
Published: February 2023

Reconfigurable optical interconnection capable of partial or full broadcasting plays a key role in optical computing and optical neural network. The interconnection can be implemented using optical matrix-vector multiplication [1]. The reconfigurability is achieved by changing the interconnection matrix written on a spatial light modulator (SLM). For a one-to-one permutation link of an array of N sources to an array of N detectors, such an approach suffers a 1/N intrinsic fanout loss [1,2].
A compact photorefractive joint transform correlator for industrial recognition tasks
Authors: Rajbenbach H. , Bann S. , Huignard J. P.
Published: February 2023

Technology advances in solid state lasers, spatial light modulators and nonlinear optical materials are centrally important for the construction of optoelectronics processors that combine the massive interconnectivity and parallelism of optics with the accuracy and flexibility of digital electronics. In pattern recognition applications, hybrid optical-digital approaches in which optics performs correlation operations and electronics processes the output correlation plane for classification have already been demonstrated(1−2). Today, the performances of semiconductor lasers, diode-pumped YAG lasers, two dimensional liquid crystal light modulators and photorefractive materials allow the introduction of compact and more flexible optical hardware in optoelectronic processors. In this paper, we present a compact and reconfigurable multichannel joint transform optical correlator designed and constructed for industrial recognition applications. The principle of operation is shown in Fig.1. The object to be identified S(x,y) is display on one half of the input scene. The other half of the input, allocated to the reference R(x,y) is split in N subarrays, or channels, each containing a reference object or a calculated version of reference object. The sum R(x,y) + S(x,y) is Fourier transformed and the spectrum is recorded in a dynamic holographic medium. The complex light field produced by reading out the joint-transform power spectrum contains the cross-correlation component R(x,y) ⊗ S (x-2a, y), where 2a is the separation between signal and reference and ⊗ denotes the correlation operation(3). The identification is performed by detecting the position and relative intensities of the correlation peaks in the corresponding subarrays of the output plane.
Closed Loop Optical Disk Based Associative Memory
Authors: Neifeld Mark A. , Psaltis Demetri
Published: February 2023

The optical disk is a simple computer addressable binary storage medium with very high capacity.
[1]
More than 1010 bits of information can be recorded on a 12cm diameter optical disk. The natural two dimensional format of the data recorded on optical disk makes this media particularly attractive for the storage of images and holograms, while parallel access provides a convenient mechanism through which such data may be retrieved. Parallel access to data stored on optical disk has been shown to provide interesting solutions to problems in neural networks, database retrieval and pattern recognition[2] In this paper we will discuss a closed loop associative optical memory based on the optical disk. When presented with a partial or noisy version of one of the images stored on the optical disk, the optical system evolves to a stable state in which those stored images which best match the input are temporally locked in the loop.
Parallel Implementations of Neural Networks: Electronics, Optics, Biology
Authors: Alspector Joshua
Published: February 2023

The DARPA report[1] notes that the human cerebral cortex is comprised of 100 billion neurons, each having about 1,000 dendrites that form about 100 trillion synapses. If you multiply that by its operating frequency of about 100 Hz, you get 10,000 trillion interconnections per second. These last two numbers (1014 connections and 1016 connections per second) form the basis for the graph in the DARPA report labeled Computational Requirements. The cortex not only has this prodigious capacity but dissipates about 10 watts, weighs 3 pounds, covers 0.15 square meters and is about 2 millimeters thick. To say it is something substantial for designers of neural systems to shoot for is a considerable understatement.
Four-foci slanted axis Fresnel lens for planar optical perfect shuffle
Authors: Carey C.D. , Selviah D.R. , Midwinter J.E. , Song S.H. , Lee E.H.
Published: February 2023

Planar optical technology offers a promising compact and robust approach for performing complex optical interconnects for silicon VLSI and WSI circuits.
A Case for All-Optical Digital Computing
Authors: Murdocca Miles
Published: February 2023

Digital electronics is a relatively mature technology, and is approaching fundamental limits in terms of density and speed. Historically, there has been a hope that the use of optical logic gates and optical interconnects will improve these limits.
Design and Construction of Looped Parallel Processors
Authors: Wakelin S. , Tooley F.A.P.
Published: February 2023

Recent advances in device technology have indicated that the role of optics in information processing systems will be in providing non-local interconnections between devices, with logic performed by the electronics.
Free-space Optical Switching Modules
Authors: Yamaguchi Masayasu , Yukimatsu Ken-ichi
Published: February 2023

Free-space optical switches are promising candidates for high-density large-scale switches required in optical computing and in telecommunication switching.
A Multiprocessor System Using Interboard Free-Space Optical Interconnects: COSINE-III
Authors: Sakano Toshikazu , Noguchi Kazuhiro , Matsumoto Takao
Published: February 2023

Optical interconnects are expected to play an important role in multiprocessor systems of the future[1]. This is because they have many advantages over conventional electrical interconnects, such as high speed, wide bandwidth, and immunity from electromagnetic interference.
Volume Holographic Storage and Processing for Large Databases
Authors: Brown Jeff , Irakliotis L.J. , Mitkas Pericles A.
Published: February 2023

Today's most powerful electronic computers are capable of processing data at rates reaching or exceeding hundreds of GFLOPS.
Crosstalkless Incoherent Optical/Electronic Hybrid Associative Memory System
Authors: Taniguchi Masaki , Matsuoka Katsunori , Ichioka Yoshiki
Published: February 2023

An associative memory is a fault-tolerant content addressable memory system.
Reflective block optics for optical computing systems
Authors: Miyazaki Daisuke , Tanida Jun , Ichioka Yoshiki
Published: February 2023

To construct an optical computing system, it is important to develop feasible technique to assemble a large amount of optical components into a complex system.
Experimental Investigation of the Tolerance of S-SEEDs and L-SEEDs
Authors: Tooley Frank A. P. , Lentine Anthony L. , Wakelin Sue , Wachlowski Alex , Goodwill Dominic , Baillie Doug A. , Simpson Kevin
Published: February 2023

Logic-SEEDs (L-SEEDs)[1] and symmetric-SEEDs (S-SEEDs)[2] have been obtained from AT&T Bell Laboratories.
Multiwavelength Logic Gates with High Computational Efficiency
Authors: Blumenthal D. J. , Sauer J. R.
Published: February 2023

The wide bandwidth of optical communications channels offers the potential for extremely high throughput for interconnects in both computer communications and telecommunications applications.
Data/Knowledge Base Processing on an ODVM platform
Authors: Stone Richard V. , Hessenbruch John
Published: February 2023

Through the utilization of an optical digital vector matrix (ODVM) processor, a mid range general purpose/ special purpose processor was designed and fabricated utilizing 8,192 optical interconnects.
Optical transpose interconnection system
Authors: Marchand Philippe J. , Marsden Gary C. , Esener Sadik C.
Published: February 2023

Optical interconnections have been shown to have advantages over electrical interconnections in terms of speed, energy and density for global links.
An Algorithm for Implementing Fully-Connected Optical Interconnection Networks with Broadcast Capability
Authors: Louri Ahmed
Published: February 2023

Broadcasting, or a one-to-all mapping, where a given node (a node in this letter refers to a processor, a memory unit, or a switch) needs to communicate with all other nodes in the system, is a key feature which can support many important activities in parallel and distributed computing.
Polarization and birefringence based optical system for reconfigurable weighed interconnects and image shifting
Authors: Peiffer Werner , Thienpont Hugo , Pelt Michiel , Vounckx Roger , Veretennicoff Irina
Published: February 2023

Three key operations are sufficient in order to construct a cellular automaton: routing and shifting of information contained in 2-D data planes, and the logic NOR operation applied on the data [1].
Optical interconnection slab based static dataflow computer
Authors: McAulay Alastair D.
Published: February 2023

Future high speed computers must be physically small and use optical interconnections in order that data movement keep up with increasing electronic processing element speeds.
Board-to-board high-speed optical interconnections
Authors: Jiang Jie
Published: February 2023

Telecommunication systems using optical fibers for high speed data transmission have been well accepted for long term.
Synchronizing and Controlling Fast Digital Optical Processors
Authors: Heuring Vincent P. , Morozov Valentin N.
Published: February 2023

This paper discusses techniques for synchronizing and controlling fast digital optical and optoelectronic processors. When optical processors require significant amounts of control for proper operation, designers have traditionally resorted to electronic host computers. Such approaches are often inadequate because of high host computer cost, or the need for speed that an electronic host computer cannot deliver. We discuss how to design controllers in the optical or optoelectronic domain. Since data and control pulses must arrive in synchronization at all interaction points, system timing and resynchronization are discussed as the major problems to be solved in designing such systems. We present solutions to the problems of timing and resynchronizing high speed optical processors in the context of two system timing paradigms: the gate and strobe paradigm and the more recent time-of-flight paradigm. Gate and strobe designs are synchronized by gating the data pulses from storage element to storage element. Time of flight systems can be synchronized by pulse reshaping: resynchronization of the weakening pulse by retiming its leading and trailing edges and by clock gating: gating a fresh copy of the master clock signal to replace a weakening signal pulse.
One-step Modified Signed-Digit Addition / Subtraction Based On Redundant Bit Representation
Authors: Huang Hongxin , Itoh Masahide , Yatagai Toyohiko
Published: February 2023

Full parallel processing requires the parallel algorithm technique, in which consistes of a suitable number systems and an efficient encoding scheme for handing the data, and parallel architectures for realizing the algorithm.
Theoretical study of the operating conditions for Symmetric Self-Electrooptic-Effect-Devices within cascaded digital optical arrays
Authors: Desmulliez Marc P.Y. , Snowdon John F. , Wherrett Brian S.
Published: February 2023

Considerable interest has been focused over the last few years on use of the symmetrical self-electro-optic-effect-device or S-SEED1-3.
Strained multiple quantum well all-optical bistable microcavity operating at 980 nm
Authors: Oudar J. L. , Pellat D. , Kuszelewicz R. , Azoulay R.
Published: February 2023

Quantum well vertical cavity structures are very attractive for the large scale implementation of parallelism in photonic systems, as they allow to fabricate 2-dimensional arrays of active functional devices such as surface emitting lasers, electro-optical modulators, and bistable optical switches.
Tandem D-STOP Architecture for Error Backpropagation Networks
Authors: Marsden Gary C. , Krishnamoorthy Ashok V. , Merckle Jean , Esener Sadik C.
Published: February 2023

Artificial neural networks have become popular, to a large extent, because of their putative ability to adaptively learn their optimal operational states.
Optical Processing System for Industrial Process Control Application
Authors: Singh Sushila , Shaligram A.D.
Published: February 2023

Process control is a time based concept. The objective is to maintain a property at some specified value in time as the manufacturing process proceeds.
Towards video rate Simulated Annealing techniques for low level image processing
Authors: Lalanne Philippe , Rodier Jean Claude , Chavel Pierre
Published: February 2023

Markov Random Fields offer a general framework for inverse problems encountered in low level image processing1,2.
Implementation of a 16-channel Sorting Module
Authors: Baillie Douglas A. , Tooley Frank A.P. , Prince Simon M. , Grant Nicola L. , Dines Julian A.B. , Desmulliez Marc P.Y. , Taghizadeh Mohammad R.
Published: February 2023

This paper will present experimental details of a sorting module demonstration system. The sorting module which is currently under construction is shown as a functional schematic in figure 1. Figure 2 is a photograph of the optics. The system implements the bitonic sort based on Batcher’s algorithm implemented with a perfect shuffle. A re-circulating rather than pipelined arrangement is used to minimise hardware requirements to 2 smart pixel chips;

• a sorting node array (self-routing exchange/bypass nodes), and

• shift register array which acts as the input/output interface.
Massively Parallel Processing with Optical Interconnections: What Can Be, Should Be and Must Not Be Done By Optics
Authors: Schenfeld Eugen
Published: February 2023

What is wrong about Optical Computing is the implied search for “general purpose computing”. We think that such an attempt has little chance to result in a practical system for, at least, the next ten years. The main reason is the economical justification. What such an “optical computing” system may offer has to be compared with the value of the application and the alternatives (electronics). On the other hand, communication in general is an area where optics has proved to be a real blessing. Long distance communication is most economically done today using optical fibers. We think that another realistic search for good optical applications should now be done for shorter distances. A possible good direction may be the communication needs of Massively Parallel Processing (MPP) systems. In such a system, large number (10’s of thousands) of Processing Elements (PEs) are to be interconnected. A PE can be seen as made of a high-end single chip CPU available today, with memory and communication circuits. We do not view the other possible meaning of MPP, namely processing and interconnections at the single gate or device level, as practical to consider. This paper describes the views of the author from the computer architecture’s standpoint, with the hope to serve as a pointer to the “Optical Computing” community. Although much has been done in the area of optical communication technology for the past 10-20 years, and many optical network experimental systems have been proposed, it seems that optics has not yet found its expected place as the interconnection technology of choice for MPP systems. In this paper we try to suggest some possible reasons preventing the common use of optical interconnections in MPP systems, in a hope to focus attention on what really needs to be done to advance the field. We would suggest focusing on searching for a processing-less solution rather than trying to mimic the existing thinking of electronic networks. We outline several key principles essential to follow to reach realistic and economical solutions of optical interconnections for MPP systems. An example of using such principles for an MPP, free-space network is presented in [1].
Detection of x-y Misalignment Error Using Optical Crosstalk in a Lenslet-Array-Based Free-Space Optical Link
Authors: Boisset G. C. , Robertson B. , Hsiao W. , Hinton H. S. , Plant D. V.
Published: February 2023

The McGill Photonic Systems Group is currently developing a free-space terabit/second capacity optical backplane implementing the Hyperplane architecture[1]. A preliminary representative portion of this backplane now being developed consists of a VCSEL-MSM link between two Printed Circuit Boards (PCBs). A simplified optical schematic is shown in Figure 1: two lenslet arrays relay signal beams generated by an array of VCSELs to the MSM device array.
Organization for a Parallel Optical Memory Interface
Authors: Deatz Gregory , Murdocca Miles
Published: February 2023

Scientific computation typically involves processing large amounts of data in which operations using main memory and mass storage are frequent. A performance bottleneck to and from main memory arises because only a small number of input and output pins are provided on electronic memory integrated circuits, which means that large portions of the memory cannot be accessed in parallel. This bottleneck is compounded by optical memories, in which entire pages can be brought into a system in parallel. Here, we describe a concept architecture that improves the access time to a parallel memory through the use of an optical interface.
Comparison of the Performance Characteristics of Futurebus+ with an Optical Backplane
Authors: Oh Tchang-hun , Kostuk Raymond K.
Published: February 2023

The use of optical interconnects for backplane and bus applications in multiboard processor systems has been considered by a number of investigators.1,2 However, most of these analyses have not evaluated the impact of optics on specific bus configurations. In this presentation we evaluate the performance of optics in a Futurebus+backplane, and show that considerable reduction in data transfer delay can be obtained using existing electro-optic interface elements in an optical backplane. The significance of this result is that a substantial improvement of existing bus architectures can be achieved using a straight forward substitution of electro-optic components for electrical transceivers.
The construction of a programmable multilayer analogue neural network using space invariant interconnects
Authors: Collings N. , Pourzand A.R. , Völkel R.
Published: February 2023

The use of a multilayer neural network is indicated in those cases of pattern classification where the input has a relatively low spatial complexity, eg 16 x 16 pixels. Such an input size arises in the post-segmentation stage of handwritten character recognition, or more generally after a pre-processing stage on more complex input scenes. Since the pre-processing is likely to be optical, eg Fourier or wavelet transform, it is of interest to consider the construction of an optical neural network where the training might be slow, due to the speed of the interface of the programmable weight matrices, but the classification stage would proceed at rates superior to electronics. This involves the use of stand-alone analog optical device for the intermediate layer of neural thresholding elements (hidden layer) in between the two layers of interconnects. The critical aspects of such an approach are the engineering of the programmable interconnect, the characteristics of the hidden layer optical device, the question of optical subtraction, and the use of discretization techniques to avoid the deleterious consequences of analog noise. The first aspect will be discussed in this summary and the other aspects will be more fully reported at the conference. The optical design of the system was presented previously [1], and this report will concentrate on the practical results.
Digital optical pipeline cellular automata arithmetic unit
Authors: McAulay Alastair D.
Published: February 2023

The arithmetic unit presents a substantial challenge to those interested in the long term goal of ultrafast all-optical general purpose computers (1 Ch. 10). Previously we demonstrated an optical adder using electron trapping materials for which the speed seems to be limited to hundreds of nanseconds (2). The multiplication of images in 160 fs was recently demonstrated by means of four-wave mixing in a new polymer material (3). We present a conceptual method of using such a material in a loop to perform pipeline digital arithmetic operations such as addition and multiplication. Only the word operands are entered at each cycle while the loop performs 2-D operations so that the rate of computation in the polymer is several orders of magnitude higher than that for data entry and removal. The method uses a modification of the transition function proposed previously for computation with cellular automata or symbolic substitution (4), (1 Ch. 15). Cellular automata on an infinite plane were shown by Dr. Von Neuman to provide universal-constructor machines capable of endlessly self reproducing new Turing machines, each of which can compute anything that can be computed by logical or mathematical reasoning (5,6). Others have subsequently provided rules for such mappings (7). Flexibility is achieved because the operation performed may be changed by replacing an optical control image. This idea of treating control information optically in the same manner as data has been highly developed in pattern logic which has been experimentally demonstrated for an optical ripple-carry adder (8, 1 Ch 9 and 10). The correlation operation required for the cellular automata is performed by four wave mixing and is independent of the control information, the data, and their locations on the array. The mapping of a full adder and a 3-bit multiplier onto such a computer are shown. The problems of achieving short pipelines for small latency are discussed and alternative possible improvements mentioned. A proposed optical set up is shown which includes a loop around a four wave mixing experiment such as that in paper (3). Some difficulties anticipated in performing such an experiment are considered.
The Design Of An Optoelectronic Graphics Display Processor
Authors: Heuring Vincent P. , Berg Melanie D.
Published: February 2023

This paper describes the design of an optoelectronic graphics display processor. The processor has the advantages of simplicity and extremely high-speed generation of computer graphic images. It achieves its speed by processing all the pixels of an image in parallel. It operates by accumulating polygons, the primitive shapes of which ail objects in the scene are composed. A front-end processor, not part of this system, is responsible for generating the coordinates and color or gray shade of each polygon and passing that information to the processor described in this paper. The processor has the capability of generating all the pixels of any arbitrary polygon in constant time. It accumulates all the polygons in a scene in a frame buffer, and when the frame buffer contains a complete image, it is available for display.
The Impact of Gate Fanin and Fanout Limits on Optoelectronic Circuit Speed
Authors: Ji Lianhua , Heuring Vincent P.
Published: February 2023

Numerous digital optical computing architectures have been proposed and demonstrated in the past years1 2 3 4. However, there is still considerable debate as to the value of these architectures in general-purpose digital computing. The main issue is that the switching speed of the devices employed is slower than electronic transistors. The continuously improving speed and cost of electronic circuits can lead to the misleading view that the future of optics is exclusively in the interconnection domain. We show here that in many practical applications, optoelectronic circuits can perform logic operations faster than electronics5. Previous comparisons of electronic logic gates with their optoelectronic counterparts did not consider the effect of gate fanin and fanout on in-circuit performance. Yet electronic gates suffer considerable performance degradation with increasing fanin and fanout. This paper will address how to systematically exploit the inherent high fanin and fanout abilities of optoelectronics to reduce circuit delay. We hope our work will provide a new design paradigm for computer architects. In addition, since fanin and fanout behavior have important implications for device designers, we hope it will provide guidance to device developers by identifying the most desirable characteristics of optoelectronic logic elements from the circuit designer’s point of view.
Software Package for Design of Free Space Optical Interconnects
Authors: Coleman Christopher L. , Keller Paul E. , Maker Paul D. , Gmitro Arthur F.
Published: February 2023

For several years our research group has investigated the design of computer generated holograms, with an eye towards producing any desired pattern of optical interconnects. We've investigated both amplitude and phase holograms, and a variety of design algorithms to produce each1. We have decided to concentrate our efforts on the phase-only holograms based on their superior reconstruction ability, diffraction efficiency, and the flexibility to produce interconnects on axis. In general, multi-level phase holograms require an iterative design approach to produce adequate results. We have developed a hybrid method which couples the Gerchberg-Saxton algorithm with a random search procedure. We have quite successfully used these routines to produce dozens of holograms for optical computing applications, including implementing weights between the synapses of an optical neural network1, producing a reference table in an optical A/D converter, and to compute carry look ahead bits in an optoelectronic adder circuit2. The method has become useful enough, that we have packaged the design software with a graphical interface to make it easier to use and more generally applicable. The rest of the paper is dedicated to a description of this software package, some issues involved with manufacturing, and directions for future work.