bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comparison of Encoding Schemes for E-beam Fabrication of Computer Generated Holograms
Authors: Farhoosh H. , Feldman M. R. , Lee S. H. , Guest C. C. , Fainman Y.
Published: February 2023

Motivated by many attractive features and capabilities of electron beam lithography systems, which include large space band-width product (SBWP), direct writing at submicron resolution, and small distortion errors, we carried out an investigation on the suitability of various encoding methods of computer generated holograms (CGH) for e-beam fabrication.
Globally Folding Combinatorial Logic Cells in Digital Optical Systolic Computing Arrays
Authors: Guilfoyle P.S. , Wiley W.J.
Published: February 2023

This paper is the third in series of publications describing various alternative combinatorial logic based optical computing architectures.1,2 Within the first paper titled "Combinatorial Logic Based Optical Computing," justification for combinatorial logic is initially debated through the coupled use of extensive optical interconnects with the natural "and-or-invert" capability of most every optical system. Figure 1 depicts the interconnect concept. Optical systems are capable of connecting points between planes in any 3 dimensional configuration by using, for example, Fourier transform holography, global fibers, or even simple lenses, depending on the interconnect complexity desired. The ability for an optical system to interconnect in three dimensions, is, in the opinion of the authors, the absolute greatest asset of an optical computer. As shown in figure 1 and explained in more detail in reference 1, should an optical computer completely exploit it's fully global interconnect capability between a set of spatial light modulators, where each has a space bandwidth product of 256 by 256, then the total interconnect gate density reaches 4 × 109. The problem plaguing silicon integrated circuit designers is the inability to interconnect various processing elements. This inability limits the chip's ultimate performance in terms of operations per square centimeter of silicon.
An Optical Arithmetic/Logic Unit Based on Residue Number Theory and Symbolic Substitution
Authors: Capps C. David , Falk R. Aaron , Houk Theodore L.
Published: February 2023

In this paper we shall show how the concepts of residue number theory1and symbolic substitution2can be combined with current technology to create a device to perform arithmetic or logic operations at gigahertz rates. Since residue arithmetic involves no "carry" operations between different positions in the representation of a number, several of these devices, each based on a different radix, may be operated in parallel to perform digital operations at a rate that is independent of word size. The present device exploits optical processing for the pattern recognition portion of its function while using electronic elements for detection and thresholding and electro-optic devices as source modulators. As nonlinear optical devices mature they can be incorporated into this arithmetic/logic unit concept to achieve an all optical device.
Demonstration of a Digital Optical Matrix-Vector Multiplier Using a Holographic Look-up Table and Residue Arithmetic
Authors: Habiby S. F. , Collins S. A.
Published: February 2023

The optical matrix-vector multiplier described in this paper uses a Hughes liquid crystal light valve as the active element, the residue arithmetic number system and a holographic table lookup. It is designed with the premise that only one light valve response time is to be used to optimize throughput and that there are a plethora of image elements available on the light valve.
Limitations to Optical Fredkin Circuits
Authors: Cuykendall Robert , McMillin Debra
Published: February 2023

Several optical Fredkin gate [Fig. 1] implementations have recently been proposed1 as building blocks for optical computers. It is shown that such conditional-routing devices can in fact be cascaded to compute the function f(x1,…,xn,y1,…, yn)=[(x1…xn)+(y1…yn)]mod2. This is accomplished through the design of a Fredkin-based minimal full adder circuit [Fig. 2] with carry-out feedback possessing the property that its control signals never interchange with data signals. Computation is performed by inserting the variable arguments initially into various control lines, while constant values are inserted into the initial data lines. The circuit is thus 'programmed' by scratchpad constants entered into its first-level data lines.
Matrix-Vector Multiplication Using Polarization Rotators
Authors: Scharf L. , Cathey W. T. , Johnson K. M.
Published: February 2023

The potential application of optical systems to perform high speed, low cost signal processing with large parallelism has attracted the attention of researchers for many years. General optical processors have been developed that compute matrix-vector multiplications and other linear algebraic operations using incoherent light. One example is the Optical Matrix- Vector Multiplier (OMVM), which calculates the discrete operation of a matrix-vector product, rather than the continuous correlation and convolution more commonly associated with optical processing [1]. The OMVM can be used to compute discrete Fourier transforms (DFT’s), and for performing linear algebraic operations, including matrix-matrix multiplications. It has been suggested as a method for implementing associative memory [3-5] and optical crossbars [4]. The first OMVM had several disadvantages, including low accuracy, low speed, and a nonprogrammable matrix mask. Recent implementations use real-time spatial light modulators (SLM) [5-7] and acousto-optic cells [8]. The two-dimensional spatial light modulators used in many of these optical processors operate at millisecond speeds, are expensive and have low resolution [5, 7]. One-dimensional modulators such as acousto-optic cells are faster, but the major drawback of computing matrix-matrix operating using one-dimensional devices is that to calculate two-dimensional matrix-matrix operations, data from the rows and columns of matrices must be loaded serially. The cycle time through the processors increases with the order of the matrix, and the natural parallelism of optics is lost.
Optical Parallel Image Processing Using CCD Image Sensor
Authors: Tokumitsu J. , Matsuoka H. , Iijima K.
Published: February 2023

Image processing is one of the most promising application fields of optical computing in which parallelism inherent in optics well matches two dimensional nature of images. Convolution is a basic operation in preprocessing images, and various kinds of methods for optically implementing it have been proposed1–3.
Optical Interconnect Complexity Limitations for Holograms Fabricated with Electron Beam Lithography
Authors: Feldman Michael R. , Guest Clark C.
Published: February 2023

As VLSI chip sizes and device densities increase, signal communication limitations begin to dominate system perfomance1,2. By replacing particular electronic transmission lines with optical signal paths, perfomance can be improved in terms of speed, alleviation of clock skew and a reduction in silicon area devoted to interconnects. These improvements can be achieved for on chip or chip-to-chip communication, but become dramatically evident for wafer scale communication. At the wafer scale level, global interconnections are infeasible to perform electronically due to the line lengths and complexity involved. In addition, arrays of parallel processing elements are utilized in order to alleviate problems of yield. The use of optical interconnections would allow for the interconnection of these processing elements in a global highly parallel manner (such as hypercube and butterfly machines) that are difficult to achieve electronically3. However, in this case the optical system must be able to handle a large number of sources, each requiring a large fanout. Highly complex interconnection schemes can be achieved with the use of a holographic optical element (HOE) for free space optical interconnections.
Optical Symbolic Computing: Architectural Considerations
Authors: Derstine M. , Guha A. , Ramnarayan R. , Vaid A. , Haugen P.R. , Husain A.
Published: February 2023

Many researchers have suggested that the parallelism of optics might be exploited for symbolic processing applications.1-8 Optics can perform functions needed for symbolic computing such as searching (using correlations) and high bandwidth data transfer (imaging). It is, however, an open question as to the applicability of optics to an overall system which does general and nontrivial symbolic computing. This paper examines how optics could be used within the framework of implementing currently specified computer languages.
Comparison of Adaptive Pattern Recognition and Image Restoration with Hetero-associative and Auto-associative Memories
Authors: Jau Jack Y. , Fainman Y. , Lee Sing H.
Published: February 2023

Our research group has recently begun an investigation on the relationship between the field of digital image processing and the field of artificial neural network. So far, we found much commonalities between the two fields in the algorithms they develop, although they frequently use different terminologies. For example, we found that image restoration is closely related to auto-associative memory, while pattern recognition is closely related to hetero-associative memory. As another example, background suppression in image processing is quite similar to attentive associative memory, while match-filtering process can be performed by accretive associative memory. In this paper we concentrate on the comparison of adaptive pattern recognition and iterative image restoration algorithms with associative mappings.
Rule-Based, Probabilistic, Symbolic Target Classification by Object Segmentation
Authors: Casasent David , Mahalanobis Abhijit
Published: February 2023

Optical symbolic processing applications in pattern recognition rather than logic operations [1,2] are considered in this paper. The database we employ is summarized in Section 2. Optical correlators represent one of the most powerful functions possible and preferable for realization on optical systems. We thus retain this architecture as the fundamental level-one symbolic processor to be used [2,3]. We utilize the attractive aspects of distortion-invariant iconic optical matched spatial filter (MSF) filters [4] in this work. We increase the flexibility, capacity and performance of such filters by using segments of the input object as separate filters (Section 3). The correlation outputs for these object sections represent the symbolic description of the input to be processed. A hierarchical set of rules for symbolic output processing and substitution is then employed (Section 4). The symbolic substitution used, the interactive expert system nature of the rule design, and the confidence of each rule are then detailed (Section 4). Tests of the system are then presented (Section 5).
Polarization-Based Optical Parallel Logic Gates Using Ferroelectric Liquid Crystal Spatial Light Modulators
Authors: Johnson K. M. , Handschy M. , Cathey W. T. , Clark N. , Walba D.
Published: February 2023

Optical computing systems offer an increased information processing rate by facilitating parallel computing architectures. Previous experience with electronic computers indicates that desired accuracy can be achieved only with digital computation. Since the simplest digital arithmetic is binary, most recent work on optical computing is focused on the construction of binary optical logic gates. Many practical implementations of such logic gates have been suggested; a recent review is given by Sawchuck and Strand [1]. Most previous schemes operate on light intensity, much in the way that electronic systems operate on voltage or current. Another natural optical scheme represents the two binary states with two orthogonal polarizations of light. The optical element necessary to implement this scheme is a device with two states, one of which passes light of a chosen polarization unchanged, and the other of which converts light of the chosen polarization to its orthogonal complement. Tsvetkov et al. [1] have described a practical implementation of this logic using the now common twisted nematic (TN) liquid crystal device, which has two voltage-selected states, one of which rotates the polarization direction of appropriately oriented linearly polarized light by 90° and the other of which has no rotary power. Another implementation would use any of the variable retardation effects such as the Pockels effect. One state of the device would be chosen to have zero retardation, and the other to have half-wave retardation. In addition to either passing unchanged or imparting 90° rotation to linearly polarized light, this scheme could also work by either passing unchanged or reversing the handedness of circularly polarized light. An advantage pointed out by Lohmann [3] that any implementation of polarization-based logic has over logics based on intensity is that no light is lost in the logical operation of inversion. In intensity-based logics, it is difficult to invert an already dark input, since light has to be "recreated"; polarization-based elements, as described above, can convert the light representing either logical state to the other, making easy the realization of any desired Boolean function.
Integrated Electrooptic Bragg Modulator Modules for Optical Computing*
Authors: Zang D.Y. , Le P. , Tsai C. S.
Published: February 2023

The prospects for realization of Lithium Niobate (LiNbO3) -based integrated optic (IO) devices and modules for applications in RF signal processing and communications have already been firmly established. For example, the planar waveguide acoustooptic (AO) Bragg cells are now widely used in the development of IO modules for spectral analysis and correlation of wideband RF signals. A variety of electrooptic (EO) devices that utilize parallel channel waveguides and crossed channel waveguides have also been developed into compact modules for wideband communications and switching as well as high-speed analog to digital conversion of RF signals. While advancements on the IO device modules for communications and signal processing are continuing, serious attemps on realization of device modules for computation of both analog and digital data have also been started recently (1-4).
Index Grating Lifetime in Photorefractive, Semi-Insulating, Cr-Doped GaAs*
Authors: Cheng Li-Jen , Partovi Afshin , Garmire Elsa
Published: February 2023

Compound semiconductors, such as GaAs and InP, are potential photo- refractive materials for real-time volume holographic elements in optical computing applications. The advantages of these photorefractive compound semiconductors include fast response1,2 (now down to picoseconds3), high sensitivity1,4, reconfigurability, high degree of parallelism, and operation at infrared wavelengths compatible with semiconductor lasers5 as well as VLSI technology. Recently, Cheng and Partovi4 investigated temperature and intensity dependence of photorefractive effect in semi-insulating, Cr-doped GaAs, revealing some operation characteristics for the semiconductor as a practical device. For example, at room temperature, minimum beam intensities of about 10 mW/cm2 are needed to form index gratings of near-saturation amplitudes, but the requirement increases to about 100 mW/cm2 at 50°C. This is due to the competing effects of the dark and light-induced electrical conductivities.
Optical NOR Gate Using Diode Laser Sources
Authors: Ojima Masahiro , Chavez-Pirson Arturo , Lee Yong H. , Morhange Jean F. , Gibbs Hyatt M. , Peyghambarian Nasser , Juang Feng-Yuh , Bhattacharya Pallab K. , Weinberger Doreen A.
Published: February 2023

Optical logic elements, especially in the form of 2-D arrays, can possibly be applied to massively parallel signal processing. GaAs/AlGaAs multiple-quantum-well etralons have previously shown optical bistability1 and various types of logic-gate operation2 at room temperature. Most of these experiments have used a dye laser, which is large in size and expensive. One attractive feature of these devices is that a GaAs/AlGaAs diode laser can be used as a light source making the total system more practical. The present paper demonstrates a stable optical NOR gate using two diode lasers.
Adaptive Optical Filtering Architecture
Authors: Price Michael G. , Craig Alan E. , Harsanyi Joseph C. , Lee John N.
Published: February 2023

This paper discusses aspects of adaptive filtering applied to narrowband interference rejection for wideband receiver systems. A time/space integrating optical architecture using a spatial light modulator is described.
Optical Associative Memory Utilizing Electrically and Optically Addressed Liquid Crystal Spatial Light Modulators
Authors: Johnson Kristina M. , Kranzdorf M. , Bigner B. J. , Zhang L.
Published: February 2023

The goal of this research is to build optical connectionist machines (OCM’s) capable of interconnecting many input units to output units via two-dimensional liquid crystal spatial light modulators (SLM’s). Liquid crystals SLM's are chosen because of their low optical absorption and power dissipation, moderate switching speeds, potential for high extinction ratios and resolution. In addition, these materials are birefringent and can easily implement a polarization-based optical associative memory. Previously, we presented results on connecting five input units to five output units [1], and eight input units to eight output units [2] with the OCM. The number of interconnections was limited by the low extinction ratio of the two-dimensional SLM used as the OCM connection matrix (The Radio Shack Pocketvision Model 5 extinction is 5:1). In this paper we present results of using higher contrast computer controlled SEIKO liquid crystal pocket television model LVD.012 and optically addressable ferroelectric liquid crystal SLM’s to hetero-associate pairs of 32 bit long input and output vectors. This association is performed using the least mean square algorithm (LMS), implemented with polarization encoding to represent both positive and negative weights.
Photorefractive Neuron by Two-Wave Mixing
Authors: Hornung-Lequeux V. , Lalanne Ph. , Taboury J. , Roosen G.
Published: February 2023

J.J. Hopfield has shown [1] that highly-interconnected neural networks have computational abilities for optimization problems and pattern recognition. The activity of a neuron can be modeled as shown in figure 1. The graded response to an excitatory or inhibitory force F is a non linear function of the input.
Photorefractive Spatial Light Modulation By Electrocontrolled Beam Coupling in SBN:Ce Crystals
Authors: Ma Jian , Liu Liren , Wu Shudong , Wang Zhijiang
Published: February 2023

The use of photoinduced dynamic refractive-index gratings for incoherent-to-coherent optical conversion or spatial light modulation has been reported, such as, four-wave mixing phase-conjugation in BSO crystals [1,2] and anisotropic self-diffraction in KNbO3 crystals [3]. The coherent reconstruction in these experiments was a negative replica of the incoherent input image. We have found a new phenomenon in SBN:Ce that the coupling direction can be altered and coupling gain can be changed by an external electric field [4]. In accordance with this effect, in the present paper a new method for incoherent-to-coherent conversion and spatial light modulation using two-beam coupling in SBN:Ce is proposed, which is suited to control the replica contrast to be either negative or positive.
InP/InGaAs Based Charge-Coupled Devices for MOW Spatial Light Modulator Applications
Authors: Han K. Y. , Chang R. , Chen C. W. , Quigley J. H. , Hafich M. , Robinson G. Y. , Lile D. L.
Published: February 2023

The use of optics for increasing the performance of signal handling systems beyond what can be achieved with electronics alone is becoming of more and more interest in a wide variety of areas. Optical communications via fiber links, interchip data routing via on chip emitters and detectors, integrated opto-electronics for a variety of circuit functions, and optical computing, all offer potential performance gains not only in speed and data handling capacity but also in ease of implementation. Associative memories and robot vision for example are applications seemingly naturally suited to optics.
Applications of Optical Symbolic Substitution to Image Processing: Median Filters
Authors: Cherri Abdallah K. , Karim Mohammad A.
Published: February 2023

Symbolic substitution (SS) based architectures [1] are actively sought for designing optical computing systems capable of processing binary data in parallel. The symbolic substitution is a two-dimensional parallel processing technique which maps a given pattern (referred to as search pattern) into a new pattern (referred to as scribe pattern).
An Inter-Pattern Association Neural Network Model and its Optical Implementation
Authors: Lu Taiwei , Wu Sudong , Xu Xin , Yu Francis T. S.
Published: February 2023

A neural network model using inter-pattern association to recognize similar patterns is proposed. A 2-D adaptive optical neural network has been used to implement the model.
Optical Implementations of Interconnection Networks for Massively Parallel Architectures
Authors: Bristow Julian , Guha Aloke , Sullivan Charles , Husain Anis
Published: February 2023

As semiconductor and electronic technologies approach fundamental physical limits in scaling and performance, the trend in high-performance computer design is to use large-scale to massively parallel architectures [1, 2, 3]. While the technology to design high-speed processing elements (PEs) has progressed significantly, the progress on designing high-performance interconnection network has not been adequate. Unfortunately, the bottleneck in performance of massively parallel architectures is typically the limited bandwidth of current interconnection networks. This is because while PEs can be densely packed on a printed wire board (PWB), there is never enough space on the board to provide all interconnection channels required for inter-PE communication at the maximum possible bandwidth. As a result, each PE is usually destined to communicate serially, often sharing communication channels with other PEs (e.g., 16 PEs in the Connection Machine share one serial line). This problem is particularly critical in fine-grained architectures where the processing time in relatively simple PEs is comparable to the communication overhead between PEs.
A Free Space Optical Interconnection Scheme
Authors: Dickinson Alex , Prise Michael E.
Published: February 2023

One of the limiting factors in the design of large scale digital systems is communication [1]. The use of conventional wiring for high speed communication entails high energy dissipation, crosstalk, ground loops and low interconnect density due to physical size constraints. Miller has shown [2] that optical interconnections have fundamentally lower energy requirements than electronic communication owing to the closer matching of impedances over all but the shortest inter-device distances, provided appropriate optoelectronic integration technology exists.
Tantalus and Optical Computing
Authors: Cathey W. Thomas
Published: February 2023

The ancient Greek, Tantalus, had a problem that is similar to that of some optical computing and signal processor researchers. As a punishment by the Greek gods, Tantalus was placed in a lake with water up to his waist. Fruit was on branches just above his head. However, when he leaned over to drink, or reached up to eat, the water receded just beyond reach and the fruit evaded his grasp. Hence, he was doomed to never obtaining what seemed so close. I do not know what deed was done by the optics researchers that deserves similar punishment (I have some ideas.), but some of the anticipated results and applications of optics to computing seem to be always just barely beyond reach.
Optical Outer Product Look-up Table Architectures for Residue Arithmetic
Authors: Heinrich Mark L. , Athale Ravindra A. , Haney Michael W.
Published: February 2023

The residue number system (RNS) allows high accuracy integer-valued arithmetic operations to be decomposed into independent (carry-free), low accuracy computations that can be performed in parallel. The RNS thus provides an attractive alternative to weighted number systems (e.g., binary or decimal) for high speed numerical computing1. The residue number representation is completely specified by a set of relatively prime moduli. The overall dynamic range is given by the product fo the moduli. Although this dynamic range can be arbitrarily high, the dynamic range required in any individual subcalculation is commensurate only with the associated modulus. The RNS also leads to a reduction in the growth of the total number of combinatorial logic elements required to perform a calculation via truth table approach. Specifically, the RNS exhibits additive growth in spatial complexity with input word size, contrasted by multiplicative (exponential) growth for weighted number systems.
Optoelectronic Parallel Processing Arrays: System Architecture and Progress Toward a Prototype
Authors: Drabik Timothy J. , Gaylord Thomas K.
Published: February 2023

It is now generally acknowledged that incorporating the advantages of optics into digital multiprocessor systems can benefit performance. Considerable interest exists in the implementation of massively parallel systems tailored to problems having high inherent parallelism, that use optics to implement some or all of the tasks of interconnection, logic, and clocking.1,2,3 We are exploring the design of digital systems based on two-dimensional arrays of electronic processing elements (PE’s) produced at or near the wafer-scale level of integration, that are optically interconnected and synchronized by means of light modulators and detectors incorporated within the PE’s and an external optical routing network. Provided a fast, reliable light modulator technology is developed that is compatible with silicon or GaAs VLSI circuit technology and signal levels, such systems will compete with all-electronic and all-optical computing systems in the regime of highly parallel and structured computation.
Single Element 2-D Bragg Cells for Optical Computing
Authors: Soos Jolanta I. , Leepa Douglas C. , Rosemeier Ronald G.
Published: February 2023

A single element 2-D Bragg cell can be used in the following subsystems: 1. Vector-vector multiplications. 2. Words equality detection. 3. Half adder optical system. 4. Global interconnection capabilities. The Brimrose 2-D device can be applied to the multiplication of two binary-digit vectors.
Synchronous Discrete Neural Networks for Minimization
Authors: Lee Hyuk
Published: February 2023

A general neural minimization algorithm which can be applied to arbitrary types of polynomial energy functions is presented. The algorithm can be operated in a synchronous as well as asynchronous way. The synchronous algorithm can be implemented by highly parallel optical systems.
Implementation of NETL Knowledge-Base System with Programmable Opto-Electronic Multiprocessor architecture.
Authors: Kiamilev Fouad , Esener Sadik
Published: February 2023

The field of Artificial Intelligence has reached a critical stage. A good Artificial Intelligence system, must include a knowledge-base with abilities comparable to those possessed by humans. To date, we have not been able to achieve this goal. Even in a restricted problem domain, current sequential search techniques are much too slow to handle a knowledge-base of sufficient size to produce a human-like intelligence, since the search time increases linearly with the increasing size of the knowledge-base.
Tolerance Analysis and Design of Optical Processors
Authors: Snowdon J.F. , Wherrett B.S.
Published: February 2023

In recent years the literature in optical computing has grown vastly and diversified widely. Many architectures have been proposed and many different devices fabricated, but remarkably few optical processors have been constructed. One reason for this is the lack of a close link between architectural considerations and device fabrication considerations. A tolerance design strategy can provide this link and enable comparative evaluation of different systems. In this paper a strategy is presented for the tolerance design of prototype optical computing circuits containing programmable logic arrays, full adders and threshold elements [1,2,3].
Optimization of Binary Phase Only Filter with Simulated Annealing Algorithm
Authors: Kim Myung Soo , Feldman Michael R. , Guest Clark C.
Published: February 2023

Binary phase only filters (BPOF) show excellent performance for matched filtering. However, when the BPOF is synthesized to distinguish similar patterns, existing encoding methods do not produce good results because the binary state of each pixel on the filter is not optimally encoded. In this paper we examine an optimum encoding of the BPOF for matched filtering to distinguish similar patterns, using a simulated annealing algorithm (1).
Quantum Well Devices for Optical Computing and Switching
Authors: Miller D. A. B.
Published: February 2023

The future prospects for both optical computing and photonic switching are clearly very dependent on advances in devices. This is especially true in the case of large scale applications requiring arrays of devices. Not only must the individual devices have good physical performance, they must also (i) operate at very low energies so that the array can be powered optically if required and have sufficiently low overall dissipation, (ii) be fabricatable in uniform arrays, and (iii) have sufficiently sophisticated functionality to allow efficient design of complex systems. Any one of these requirements suggests integration; taken together, we can see that a technology that offers straightforward integration of large numbers of flexible devices is essential for such array applications. Given that there are very few physical mechanisms that can offer sufficiently low operating energies for optical devices regardless of integration, we can see that this is a hard problem.
Programmable Logic Gate Array and its Applications to Reconfigurable Network Based on Modified Sign Digit
Authors: Suzaki Yoshiki , Yatagai Toyohiko
Published: February 2023

We have developed a programmable parallel logic unit with a dynamic interconnection ability based on the truth table architecture. This enable us to design very flexible digital optical computing systems. An element cell has two input ports and three output ports, as shown in Fig. 1. Element cells are connected optically each other, and the connection network is changeable by selecting three output ports. The element cell is able to select which output ports are active or not. Because of this feature of the element cell the interconnection network is dynamically configured. It is convenient to use three-state logic or ternary logic to assign one or two of three ports to the output output port. Ternary logic is also employed to perform a modified sign digit (MSD) operation, which enables us to make a full parallel algorithm of numerical calculation.
Business and Technological Issues for the Commercialization of Optical Computing
Authors: Kressel Henry
Published: February 2023

The major technological elements encompassed by optical computing will be discussed in terms of their applications. Comparisons with the successful commercial introduction of other optical technologies will be made in order to highlight the elements which contributed to their success.
All-optical Full-adder Based on Zinc Sulphide Optical Bistable Device
Authors: Ruibo Wang , Zizhong Zha , Lei Zhang , Chunfei Li
Published: February 2023

Optical computing systems constructed with relatively slow logic devices and massively parallel configurations could have very high processing rates. For this reason, great attention has been paid on circuits based on lower power, moderate speed, nonlinear interference filter logic devices. Single-gate full-adder was proposed and realized by B.S.Wherrett et al[1,2]. In their experiment, input signals were input with an incident angle. Here we report the experimental demonstration of a single gate full-adder with on-axis input and put forward a design of multi-bit full-adder.
Theoretical Description of the Bimodal Optical Computer
Authors: Scholtz A V , van Rooyen E
Published: February 2023

The use of optical processors for fast numerical calculations has always been hampered by the inherent inaccuracies of analog optics. Numerous techniques have been proposed to overcome this deficiency. One of these, the Bimodal Optical Computer (BOC), proposed by Caulfield et al[1], has generated considerable interest lately. The BOC (shown in fig.l) is a hybrid processor dedicated to solving a set of linear algebraic equations (LAE’s). It consists of an iterative optical processor that uses continuous analog feedback, coupled to a digital processor to ensure high accuracy through a process of iterative refinement.
Optical Bus Interconnection System by Using Selfoc Lenses and Planar Microlens Arrays
Authors: Hamanaka Kenjiro
Published: February 2023

Optical interconnection in optical processing system or in electronic computer system has many potential advantages in terms of channel capacity, transfer rate and so on. Recently, many types of optical interconnection system have been proposed and examined[1,2]. Free-space (three-dimensional) optical system can deal with the large amount of information, however, it is difficult to achieve precise assembling and high durability.
Compact Crossbar Switch For Optical Interconnects
Authors: Lin Freddie , Strzelecki Eva M. , Liu William
Published: February 2023

Optical crossbar switches are used in a variety of applications: in optical computing, optical communications, and optical interconnects in computers. High speed optical crossbars have been demonstrated for the use in communications such as waveguide electro-optic switches in LiNbO3 [1], semiconductor quantum well modulators [2]. For applications in optical computing it is important to have very large switching arrays to utilize the massively parallel capability of optical signal processing. This has been achieved using spatial light modulators (SLM) which are available in large arrays, such as liquid crystal TVs and ferroelectric liquid crystal devices [3], and high speed, such as PLZT [4] or quantum well modulators [2]. Many systems based on SLMs utilize the vector-matrix multiplication configuration to realize crossbar networks, linear algebra operations, iterative vector-matrix multiplication, and optical neural networks. Crossbars based on this configuration, though suffer from fan-out losses, are very versitile, offer broadcasting capability needed in optical interconnects, and can easily form large array sizes. Most SLM based systems, which use bulk optics, lenslet arrays, and fiber optic couplers [5], are bulky and require tedious alignment. In this paper we describe a compact vector-matrix mulitplier in which waveguides with arrays of grating couplers are used to distribute and collect light signals.
A Figure of Merit for Pattern Recognition Filters
Authors: Refregier Ph.
Published: February 2023

The design of filters for optical pattern recognition is extensively studied for more than ten years [1] [2] [3] [4] [5]. Indeed, optical correlation implementation leads to specific constraints in comparisons with classical signal processing technics [6]. In particular, although the spatial matched filter is optimal for noise robustness, its limitations such as broad correlation peaks and low diffraction efficiency [3] are well known. Many different approaches have improved some of these characteristics and a lot of work is still devoted to find trade-offs between them [7] [8] [9] [10] [11] [12].
Optoelectronic Neuron
Authors: Rohlev Anton , Radehaus Christian , Pankove Jacques I. , Carson R. F. , Borglis G.
Published: February 2023

In analogy to biological neurons that interact with other neurons both electrically and chemically, the optoelectronic neurons interact with other optoelectronic neurons electrically and/or optically. Like a biological neuron, the optoelectronic neuron can have multiple input and thresholding. While the chemical interaction between biological neurons can employ different neurotransmitters, the optical interaction between optoelectronic neurons can employ photons of different wavelengths.
Design and Demonstration of an Opto-EIectronic Neural Network using Fixed Planar Holographic Interconnects
Authors: Keller Paul E. , Gmitro Arthur F.
Published: February 2023

A key element of most neural network systems is the massive number of weighted interconnections used to tie relatively simple processing nodes together in a useful architecture. The inherent parallelism and interconnection capability of optics make it a likely candidate for the implementation of the neural network interconnection process. While there are several optical technologies worth exploring, we are looking at the capabilities and limitations of using fixed planar holographic interconnects in a neural network system and have implemented an initial test system using planar holograms and opto-electronic nodes.
Custom designed electro-optic components for optically implemented, multi-layer neural networks
Authors: Robinson M.G. , Johnson K.M. , Jared D. , Doroski D. , Wichart S. , Moddel G.
Published: February 2023

Optical implementations of one-layer, perceptron-like neural networks have been shown to be very successful at associating pattern/target sets despite large system errors [1,2]. It has also been shown that large systems can be realized with such architectures (≥4 x 104 interconnections [2,3]), and appreciable processing speeds have been demonstrated (>108 interconnections/sec [4]). However, single layer networks are limited due to their inability to associate patterns that are not linearly separable. A more general network is the two layer network, which is able to model arbitrary functions, and create any decision boundary within the input vector pattern space [5]. In order to implement such a network, it is necessary to perform a nonlinearity at the hidden layer before performing a subsequent matrix multiplication. In general, optical materials performing fast nonlinear processing require high optical powers. Hybrid opto-electronic devices can perform nonlinear operations at moderate speeds and low optical powers [6].
Digital Optical Computer II (DOC-II): “Performance Specifications”
Authors: Guilfoyle Peter S. , Rudokas Ronald S. , Stone Richard V. , Roos Edward V.
Published: February 2023

Currently OptiComp® Corporation is completing construction of the first 32-bit general purpose digital optical computer. This effort is sponsered jointly by the Office of Naval Research (ONR), Strategic Defense Initiative (SDI), NASA space station and the Rome Air Development Center (RADC/USAF).
Adaptive Fuzzy Systems
Authors: Kosko Bart
Published: February 2023

Fuzziness is multivaluedness. Truth, set membership, and subset containment take on degrees in [0, 1] instead of taking on only the limiting bivalent extremes in {0, 1}. The degrees in [0, 1] define fuzzy units, or fits. Statements are true to some degree. An element belongs to, or fits in, a fuzzy set to some degree. One fuzzy set contains another fuzzy set to some degree.
Optoelectronic Fuzzy Logic System
Authors: Marsden Gary C. , Olson Brita , Esener Sadik , Lee Sing H.
Published: February 2023

It is often the case in reasoning problems that propositions are neither entirely true nor entirely false. In fuzzy logic,1,2 the truth values of propositions are not restricted to true or false, but rather may range between zero (absolutely false) and one (absolutely true), allowing a quantitative representation and evaluation of vague propositions. For example, the proposition, "Marsden is a boring speaker" is neither totally true nor totally false, but might have a value 0.30.3 Many existing Boolean reasoning methods can be extended to include fuzzy truth values. However, since Boolean operators such as AND and OR are undefined on non-Boolean data, analogous fuzzy operators must be defined for these algorithms to be useful. It has been shown that MIN and MAX have desirable properties when used as extensions of AND and OR, respectively.1
Hologram multiplexing using orthogonal phase codes and incremental recording
Authors: Taketomi Yoshinao , Ford Joseph E. , Sasaki Hironori , Ma Jian , Fainman Yeshayahu , Lee Sing H. , Feinberg Jack
Published: February 2023

Photorefractive volume holography may prove useful for optical interconnection and data storage applications. However, the process of recording a set of uniform, high quality superimposed holograms normally involves a complicated recording procedure using a schedule calculated from the detailed material characteristics1,2. A small error in material characterization (or change in the material characteristics) can result in highly nonuniform diffraction efficiencies. In this paper, we present a new incremental recording approach that relies only on an approximate knowledge of the materials characteristics. By avoiding long exposures, we avoid the high gain and fanning which tend to disrupt photorefractive performance. To achieve the highly repeatable recording necessary for this approach we use a set of orthogonal phase images for the reference beams. This choice minimizes readout of any unwanted images. The phase only reference images will be more reproducible when generated by a stationary phase spatial light modulator, compared to angular multiplexing. Compared to the simple sequential schedule of recording, the use of phase-coded reference beams and incremental recording of the holograms should produce brighter images with an improved signal-to-noise ratio.
Generalization in an Optical On-Line Learning Machine
Authors: Wullert John R. , Paek Eung Gi , Patel J.S.
Published: February 2023

Neural networks, characterized as a large number of highly interconnected simple processors, can be trained by varying the strength (weight) of the interconnections (synapses) between the simple processors (neurons). Several holographic optical systems have physically demonstrated this capability previously.[1][2][3][4] Since neural networks are trained by example rather than programmed with specific rules, they are likely to be able to generalize, or recognize patterns that do not exactly match those used for training. Such generalization is important in real world pattern- recognition problems where the size, orientation, position and background cannot be determined in advance.
The First Demonstration of an Optical Learning Chip
Authors: Kyuma Kazuo , Nitta Yoshikazu , Ohta Jun , Tai Shuichi , Takahashi Masanobu
Published: February 2023

Recently, there has been a strong interest in artificial neural networks for real time applications. Among several approaches, opto-electronic neural networks1) are quite attractive because of a dense-interconnection, a parallelprocessing, and a large-scale integration capabilities using the advanced GaAs semiconductor technologies.
Nonlinear thresholding characteristic for optical computing of optically addressable GaAs/FLC-SLM
Authors: Hashimoto Masashi , Fukuda Yukio , Ishibashi Shigeki , Kitayama Ken-ichi
Published: February 2023

In a wide variety of optical parallel processings, spatial light modu1ators (SLMs) (1), especially optically addressable SLMs(OASLMs), are versatile devices. SLMs have been used as an optical encoder and latch memory for optical computing(2) and synaptic weighting mask for optical neural network. (1)
Progress in optical interconnection technologies and demonstrators under the ESPRIT II OLIVES programme
Authors: Parker J.W.
Published: February 2023

OLIVES (Optical Interconnections for VLSI and Electronic Systems) is a three year collaborative project which commenced in January 1989 and combines the complementary skills of four major electronics companies (STC, Siemens, Plessey and Thomson-CSF), a chemical company (Akzo) and five academic institutions (University College London (UCL), Foundation for Research and Technology, Hellas/RCC, Centro Nacional de Microelectronica (CNM), Interuniversitair Microelectronic Centrum (IMEC), and Eldgenössishe Technische Hochschule Zurich (ETH)). Some of the key aims and achievements to date in this project are described.
Experimental implementation of a 25 channel free-space optical switching architecture
Authors: Kirk Andrew , Jamieson Stuart , Imam Hussain , Hall Trevor
Published: February 2023

There are many areas within optical telecommunications and optoelectronic information processing in which an optical space-switch is required to reconfigurably interconnect two arrays of optoelectronic devices.
Spatial Soliton Dragging Gates and Light Bullets
Authors: Wagner Kelvin , Mcleod Robert
Published: February 2023

The asymmetric interaction between two orthogonally polarized, self-focusing spatial soliton filaments in a slab waveguide of nonlinear Kerr media can result in the spatial dragging of a strong pump beam by a weak signal wave.
An Integrated Optics, Stored Program Computer
Authors: Jordan Harry F. , Mickelson Alan R. , Van Zeghbroeck Bart , Januar I.
Published: February 2023

A serial, stored program, optical computer has been designed [1] and implemented [2] using LiNbO3 electro-optic directional coupler switches. Detector, amplifier and driver electronics at each electro-optic switch adapt it to optical control, so that all inter-switch signals are optical. The demonstrated machine uses discrete components, and glass fiber forms both interconnection and delay line memory. This paper will project the properties of an integrated version of this computer.
Cascaded Operation of Two 128-Pixel FET-SEED Smart Pixel Arrays
Authors: McCormick F. B. , Lentine A. L. , Chirovsky L. M. F.
Published: February 2023

The current trend in device design for free-space optically interconnected systems is towards 2-D arrays of smart pixels, in which each pixel incorporates electronic processing together with optical I/O.
Non-Blocking Optical Interconnection Networks using Electro-Optical Matrix Switches based on VSTEPs
Authors: Araki S. , Kawai S. , Kurita H. , Numai T. , Kasahara K. , Kubota K.
Published: February 2023

Optical interconnections have promising features for interconnection networks in massively parallel computers. One of the reasons is that light beams can cross each other with no mutual interference.
Polarization-Selective Computer-Generated Holograms for Optical Multistage Interconnection Networks
Authors: Ford Joseph , Xu Fang , Krishnamoorthy Ashok , Urquhart Kristopher , Fainman Yeshayahu
Published: February 2023

Computer-generated holograms (CGH) fabricated as phase-only optical elements have proven to be useful in implementing free space optical interconnections for parallel computing and communications.
Massively Parallel Processing System with an Architecture for Optoelectronic Computing
Authors: Ishikawa Masatoshi , Morita Akira , Takayanagi Nobuo
Published: February 2023

Recently there are growing interest in integration of optical devices such as OEIC’s, surface emitting lasers, photo detectors, and so on.
High-Speed Database Processing on an Optical Content-Addressable Parallel Processor(OCAPP)
Authors: Louri Ahmed , Hatch James A
Published: February 2023

Recently, an efficient optical architecture, known as Optical Content-Addressable Parallel Processor(OCAPP), has been introduced for the efficient implementation of symbolic computing tasks [1].
A Neural Network Router for Optical Interconnection Networks
Authors: Lee Giles C. , Goudreau Mark W.
Published: February 2023

Artificial Neural Networks (ANNs) of the type that were described by Hopfield [8] are capable of finding good solutions for certain optimization problems [7].
Multiwavelength Optical Half Adder
Authors: Yeh Pochi , Campbell Scott , Zhou Shaomin
Published: February 2023

In the past decade there have been many proposals for and demonstrations of digital optical computing architectures [1-7].
Second Order Neural Network Implementation Using Asymmetric Fabry-Perot Modulators
Authors: Jennings Andrew , Kelly Brian , Hegarty John , Horan Paul
Published: February 2023

Many optical neural network implementations using vector/matrix multipliers are based on first order networks in which each input neuron is connected to an output via a weighted interconnection.