Optical computing Research Papers - Academia.edu (original) (raw)

A method is presented for the recovery of optical flow. The key idea is that the local spatial structure of optical flow, with the exception of surface boundaries, is usually rather coherent and can thus be appropriately approximated by a linear vector field. According to the proposed method, the optical flow components and their first order spatial derivatives are computed

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- Mathematics, Computer Science, Computer Vision, Linear Algebra

This paper presents a new intensity-to-time processing paradigm suitable for very large scale integration (VLSI) computational sensor implementation of global operations over sensed images. Global image quantities usually describe images with fewer data. When computed at the point of sensing, global quantities result in a low-latency performance due to the reduced data transfer requirements between an image sensor and a processor. The global quantities also help global top-down adaptation: the quantities are continuously computed on-chip, and are readily available to sensing for adaptation. As an example, we have developed a sorting image computational sensor-a VLSI chip which senses an image and sorts all pixel by their intensities. The first sorting sensor prototype is a 21 2 2 2 26 array of cells. It receives an image optically, senses it, and computes the image's cumulative histogram-a global quantity which can be quickly routed off chip via one pin. In addition, the global cumulative histogram is used internally on-chip in a top-down fashion to adapt the values in individual pixel so as to reflect the index of the incoming light, thus computing an "image of indices." The image of indices never saturates and has a uniform histogram.

- by Vladimir Brajovic
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- Mechanical Engineering, Computer Science, VLSI, Image segmentation
- by Ramesh Jain
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- Information Systems, Artificial Intelligence, Computer Vision, Image Processing

A single-photon source based on single CdSe quantum-dot fluorescence in a chiral-photonicbandgap liquid-crystal host manifests itself in observed fluorescence antibunching. Chiral-photonicbandgap structures will provide deterministically... more

- by Svetlana Lukishova
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- Quantum Computing, Photonic Crystals, Liquid Crystals, Fluorescence

Abstract-Backtracking search is frequently applied to solve a constraint-based search prob!em, but it often suffers from exponential growth of computing time. We present an alternative to backtracking search: local search with conflict... more

- by Yassine Ait Bella
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- Computer Science, Operations Research, Very Large Scale Integration, Case Study
- by sohail sheikh
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- Computer Science, Image Processing, Signal Processing, Nonlinear Optics

Purpose: To extend the Radiological Physics Centre (RPC) intensity-modulated radiation therapy dose verification protocol to three dimensions using optical computed tomography (CT) scans of ferrous xylenol-orange (FX) gels. Methods and Materials: The dosimetry insert in the RPC head-and-neck phantom was replaced with an FX cylindrical gel dosimeter. Two gels were calibrated, independently irradiated with 6-MV X-ray beams and scanned using laser and cone-beam (VistaÔ) optical CT, respectively. For matching dose slices, measured dose distributions were compared with Pinnacle 3 computed distributions. Results: Within high-dose regions and low gradients, doses measured using laser CT were 2% to 3% less than the computed dose, whereas with cone-beam CT they were 4% to 5% less. Inside the central 90% of the gel cylinder diameter, the fraction of voxels satisfying the two-dimensional gamma analysis (5% dose difference, 3-mm distance to agreement) with laser-beam-and cone-beam-measured dose distributions were 98.4% and 99.0%, respectively. A three-dimensional gamma analysis with cone-beam data revealed that 96.7% of voxels within the central 90% gel volume satisfied the above criteria. Within the axial and sagittal planes through the primary planning target volume (PTV), computed and measured doses using GAFChromic Ò EBT film (RPC measured) and cone-beam scanned FX gel generally agreed. At equivalent points in the planning target volumes, computed, thermoluminescent dosimeter (RPC-measured), and gel point doses agreed to within 5.1% in absolute dose. Conclusions: Laser and cone-beam CT yield comparable dose distributions in high-dose regions. The RPC head phantom and optical CT-scanned FX gels can be used for accurate intensity-modulated radiation therapy dose verification in three dimensions. Ó 2008 Elsevier Inc.

Nowadays, a lot of educational and research objectives can be achieved through the use of configurable, small, low-cost mobile robot kits. Using these systems, students must deal with topics like teamwork, real-world issues, integrated systems building, multidiscipline information, etc. This paper will present a mobile robot laboratory. The laboratory is based on the LEGO Mindstorms programmed with LegOS. With this environment a wide variety of robot activities can be developed due to its flexibility, power, and simple use.

- by Jose Luis Diez
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- Communication System, LEGO Mindstorms, Teamwork, Mobile Robots

The Sagnac all-optical fiber logic gate functions as a two-input AND gate, a two-input AND gate with one inverting input, or both. The fiber logic gate is pipelined and has a fixed latency. This latency has no effect on feed-forward combinatoric circuits. The latency can be used to time multiplex circuits or to time multiplex gates to emulate a circuit. Possible applications such as a bit-jitter-tolerant communications system, an asynchronous communications system, a bit-interleaved self-routing switching system, an exchange/bypass permutation unit, and a folded universal state machine are discussed.

- by Alan Huang
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- Mechanical Engineering, Optical Communication, Information Processing, Applied

Focal plane processing applications present a growing computing need for portable telecomputing and videoputing systems. This paper demonstrates the integration of digital processing, analog interface circuitry, and thin film OE devices into a compact computing package. The SIMPil architecture provides a programmable, silicon efficient SIMD processor for effective execution of early image processing applications such as edge detection, convolution, and compression. Results from a demonstration SIMPil node are presented including its microarchitecture, and performance on image processing applications.

- by Martin Brooke
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- Computer Architecture, Image Processing, Packaging, Image compression

An interconnection pattern corresponding to a transposition arises naturally when a connection is required befween a set of modules in a stage and a second set of modules. The optical transpose interconnection system (OTIS) was first proposed by Gary C. Marchand et al. and has been exploited in a FAST-Net demonstrator by P. Milojkovic et a/. These implementations employed a scheme based on off-axis imaging. This paper aims to propose an alternative non-imaging scheme of the optical transpose interconnection system by interposing a macrolens, a Fourier transform lens, between the two stages of mesolens arrays. This scheme is shown to be superior in several respects. In order to describe a transposition of the coordinates of input beamlets to the coordinates of output beamlets, the ray of light through the optical system will be represented by points specified by p, the direction cosine, and 4, the position, in phase space. The system is useful for implementation of three-stage Clos Networks, the Optical Transpose Sector Switch (OTSS), a reconfigurable Optical Transpose system, and an Optical Crossbar Switch.

- by Sadik Esener
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- Quantum Physics, Computer Network, Optical computing, Nodes

The synthesis of a new category of spatial filters that produces sharp output correlation peaks with controlled peak values is considered. The sharp nature of the correlation peak is the major feature emphasized, since it facilitates target detection. Since these filters minimize the average correlation plane energy as the first step in filter synthesis, we refer to them as minimum average correlation energy filters. Experimental laboratory results from optical implementation of the filters are also presented and discussed.

- by B K
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- Mechanical Engineering, Optics, Medical Imaging, Fiber Optics

This article addresses the development of and recent advances in the rapidly growing jield of optical pattem recognition. In optical pattern recognition there are two basic approaches; namely, matched filtering and associative memories. The first employs optical correlator architectures and the latter uses optical neural networks (NN's). This paper reviews various types of optical correlators and NN's applied to real-time pattern recognition and autonomous tracking. Techniques of scale and rotational invariant jiltering are also given. Recent approaches using wavelet transfom filtering, phase only jiltering, high capacity composite filters, and phase representation f o r improvement in pattern discrimination are also provided.

- by Don Gregory
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- Biomedical Engineering, Pattern Recognition, Neural Networks, Neural Network

Multilayer neural networks trained with the back-propagation algorithm constitute the best example of a successful gradientbased learning technique. Given an appropriate network architecture, gradient-based learning algorithms can be used to synthesize a complex decision surface that can classify high-dimensional patterns, such as handwritten characters, with minimal preprocessing. This paper reviews various methods applied to handwritten character recognition and compares them on a standard handwritten digit recognition task. Convolutional neural networks, which are specifically designed to deal with the variability of two dimensional (2-D) shapes, are shown to outperform all other techniques.

The Archimedes Palimpsest is a tenth-century manuscript that contains the earliest known copies of parts of seven treatises by Archimedes, plus several pages from other works of great historical significance. Among the Archimedes treatises are the only extant copies of On the Method of Mechanical Theorems, which describes Archimedes' thought processes for deriving proofs of mathematical conjectures by using mechanical analogies, the Stomachion, which is now believed to be the oldest known study of combinatorics, and the oldest known example of Archimedes' most famous work, On Floating Bodies, in the original Greek. Several multispectral imaging techniques have been applied to high-resolution images of the palimpsest to provide scholars of ancient Greek mathematics with visible text for inquiry. It is estimated that about twenty percent of the Archimedes text requires additional scientific techniques to be transcribed. Efforts in character recognition are currently being pursued to provide scholars with another tool for retrieving as much information as possible from the remaining degraded text. The current pattern recognition system does not produce a single result, as in typical target detection problems, but rather has been designed to provide intermediate results that allow the user to apply decisions or evidence to arrive at a conclusion. We describe the algorithms used in constructing the tool, and report on the recognition results.

- by Roger Easton
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- Mechanical Engineering, History, Multispectral Imaging, History of Science

In the era of Internet of Things and with the explosive worldwide growth of electronic data volume, and associated need of processing, analysis, and storage of such humongous volume of data, it has now become mandatory to exploit the power of massively parallel architecture for fast computation. Cloud computing provides a cheap source of such computing framework for large volume of data for real-time applications. It is, therefore, not surprising to see that cloud computing has become a buzzword in the computing fraternity over the last decade. This book presents some critical applications in cloud frameworks along with some innovation design of algorithms and architecture for deployment in cloud environment. It is a valuable source of knowledge for researchers, engineers, practitioners, and graduate and doctoral students working in the field of cloud computing. It will also be useful for faculty members of graduate schools and universities.

Using residue arithmetic it is possible to perform additions, subtractions, multiplications, and polynomial evaluation without the necessity for carry operations. Calculations can, therefore, be performed in a fully parallel majiner.' Several different optical methods for performing residue arithmetic operations are described. A possible combination of such methods to form a matrix vector multiplier is considered. The potential advantages of optics in performing these kinds of operations are discussed.

- by Alan Huang
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- Mechanical Engineering, Optics, Medical Imaging, Signal Processing

All-optical networking can be the sole approach to provide the huge bandwidth required for future networks. The essential elements in such an optical network are optical switches. A number of options have been proposed in order to implement them efficiently. We focus on thermooptical switches. First, the physical principles of the thermo-optic effect are briefly introduced. A description of the most common technologies used for the fabrication of thermo-optic switches is provided along with the values of thermo-optic coefficient for a number of materials. The main steps useful in order to design thermo-optical switches are also briefly introduced. Finally, a bird's-eye view of the main and recent proposals of switches based on the thermo-optic effect is reported and their performances compared. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).

- by Mario Iodice
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- Optical Engineering, Optical Communication, Neural Network, Optical Switch

Fruit peel coloring is one of the most important measures of commercial values in various citrus fruits. It is well documented that a gaseous plant hormone, ethylene, regulates the peel color changes associated with fruit ripening. To handle the peel color quality, it is necessary to develop a universal measure of ethylene-directed color changes. Here, we proposed a novel colorimetric formula: y* = [ (L* n • max-L* t) 2 + (a* n • max-a* t) 2 + (b* n • max-b* t) 2 ] 1/2 (y* > 0), based the CIE 1976 L*a*b* colour space units, which reflect the wholistic changes in fruit color. Since all known colorimetric values are specialized for estimation of the changes in certain single pigment, our formula may be useful for assessing the total fruit color development in a controlled atmosphere.

- by Tomonori Kawano
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- Agricultural Engineering, Biochemistry, Botany, Food Science

The Hankel transform of a function by means of a direct Mellin approach requires sampling on an exponential grid, which has the disadvantage of coarsely undersampling the tail of the function. A novel modified Hankel transform procedure, not requiring exponential sampling, is presented. The algorithm proceeds via a three-step Mellin approach to yield a decomposition of the Hankel transform into a sine, a cosine and an inversion transform, which can be implemented by means of fast sine and cosine transforms.

- by L. Knockaert
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- Decomposition, Convergence, Inverse Problems, Multidisciplinary

We apply opticaJ computing techniques to basic problems in computational geometry. We present an abstract computational model for optical computing and show its applicability to the efficient solution of geometric problems. Many such problems can be solved with a constant number of optical operations. We also discuss the advantage of optical computing over classical techniques in computational geometry and study issues in the design and analysis of geometric algorithms based on optical computing.

This paper considers the problem of designing electron guns using computer optimization techniques. Several different design parameters are manipulated while considering multiple design criteria including beam and gun properties. The optimization routines are described. Examples of guns designed using these techniques are presented. Future research is also described.

- by Thuc Tran
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- Optimal Control, Finite Element Methods, Finite Element, Finite Element Analysis
- by Juyang Weng
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- Grid Computing, Image Analysis, Crime scene analysis, Motion estimation

The modeling of system and component noise and error sources in optical linear algebra processors (OLAP's) are considered, with attention to the frequency-multiplexed OLAP. General expressions are obtained for the output produced as a... more

- by Anjan Ghosh
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- Quantum Physics, Linear Algebra, Optical computing, Optical physics

Self-oscillations in nonlinear optical four-wave mixing and resonators are considered. Some unique properties of these oscillations can be employed for implementing parallel optical thresholding, comparing, and maximum operations. Both theoretical and experimental results that are obtained by utilizing the photorefractive nonlinearity are presented and discussed.

- by Claire Gu
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- Mechanical Engineering, Nonlinear Optics, Parallel Processing, Information Processing

This tutorial survey paper reviews several different models for light interaction with volume densities of absorbing, glowing, reflecting, and/or scattering material. They are, in order of increasing realism, absorption only, emission only, emission and absorption combined, single scattering of external illumination without shadows, single scattering with shadows, and multiple scattering. For each model I give the physical assumptions, describe the applications for which it is appropriate, derive the differential or integral equations for light transport, present calculations methods for solving them, and show output images for a data set representing a cloud. Special attention is given to calculation methods for the multiple scattering model.

- by Nelson Max
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- Grid Computing, Computational Modeling, Light Scattering, Integral Equations

Swarm . Optimizer which deals with permutation problems. Particles are defined as permutations of a group of unique values. Velocity updates are redefined based on the similarity of two particles. Particles change their permutations with a random rate defined by their velocities. A mutation factor is introduced to prevent the current pBest from becoming stuck at local minima. Preliminary study on the n-queens problem shows that the modified PSO is promising in solving constraint sstisfication problems.

It is known that convolutional neural networks (CNNs) are efficient for optical character recognition (OCR) and many other visual classification tasks. This paper applies error-correcting output coding (ECOC) to the CNN for segmentation-free OCR such that: 1) the CNN target outputs are designed according to code words of length N; 2) the minimum Hamming distance of the code words is designed to be as large as possible given N. ECOC provides the CNN with the ability to reject or correct output errors to reduce character insertions and substitutions in the recognized text. Also, using code words instead of letter images as the CNN target outputs makes it possible to construct an OCR for a new language without designing the letter images as the target outputs. Experiments on the recognition of English letters, 10 digits, and some special characters show the effectiveness of ECOC in reducing insertions and substitutions.

- by george stathopoulos
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- Pattern Recognition, Neural Networks, Neural Network, Image Classification

All-optical digital devices are key components for advanced signal processing in next generation optical networks and optical computing. In most digital systems, photonic integrated circuits are required to carry out high-speed energy efficient functionalities. In this paper, an entire set of integrable all-optical clocked flip-flops and an all-optical binary counter are proposed, as applications of SR latches and logic gates previously introduced in literature. The SR latch is based on gain quenching mechanism between two coupled ring lasers using a semiconductor optical amplifier (SOA) as active element. Photonic logic functions are carried out by exploiting four wave mixing (FWM) and cross gain modulation (XGM) nonlinear effects in SOAs. Different flip-flop logical functionalities, including SR-, D-, T-, and JK-types, as well as an all-optical binary counter, are obtained by adding one of the logic gates, or a combination of them, to the latch scheme. The effectiveness of the proposed schemes is demonstrated by extinction ratio and Q-factor measurements. All solutions are tunable in the whole C-band and can work at different counting rate without any reconfiguration. Photonic integration allows to increase the functioning rate beyond gigahertz and reduce the switching energy. Index Terms-Optical flip-flop, optical logic gates, optical signal processing, semiconductor optical amplifier (SOA). I. INTRODUCTION I N ORDER to meet the ever-increasing demand of data communication for future optical networks, high-speed digital processing is required.

- by gianluca berrettini
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- Quantum Physics, Signal Processing, Q factor, Optical computing

Advances in optical CT scanning for gel dosimetry K Jordan Dose response of ferrous-xylenol orange gels: the effects of gel substrate, gelation time and dose fractionation K Jordan and J Battista Low diffusion rate leuco crystal violet gel

- by Kevin Jordan
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- Engineering, Radiology, Water, Nuclear medicine

Reversible logic is the basis for several emerging technologies such as quantum computing, optical computing, or DNA computing and has further applications in domains like low-power design and nanotechnologies. However, current methods for the synthesis of reversible logic are limited, i.e. they are applicable to relatively small functions only. In this paper, we propose a synthesis approach, that can cope with Boolean functions containing more than a hundred of variables. We present a technique to derive reversible circuits for a function given by a Binary Decision Diagram (BDD). The circuit is obtained using an algorithm with linear worst case behavior regarding run-time and space requirements. Furthermore, the size of the resulting circuit is bounded by the BDD size. This allows to transfer theoretical results known from BDDs to reversible circuits. Experiments show better results (with respect to the circuit cost) and a significantly better scalability in comparison to previous synthesis approaches.

- by Rupali Singh
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- Quantum Computing, Quantum Logic, Optical computing, Data Structures

Determining whether a Diophantine equation has a solution or not is the most important challenge in solving this type of problems. In this paper a special computational device which uses light rays is proposed to answer this question, namely check the existence of nonnegative solutions for linear Diophantine equations. The way of representation for this device is similar to an directed graph, having a number of nodes equal to the number of variables of the equation plus the destination node. The arcs connecting these nodes have assigned a number (length) which corresponds to coefficients of the equation or it is a predefined constant. The light traversing the device follows all possible routes. In each arc it will be delayed by an amount of time indicated by the length of that arc. At the destination node, if a light ray arrives at the moment equal to the free term of the equation plus some constants we may infer that the equation has solution, otherwise it has not.

- by Mihai Oltean
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- Optical computing, Optical physics, Directed Graph

An N bit all-optical comparator and an all-optical full adder are presented. These complex circuits, which perform photonic digital processing, are implemented cascading a unique basic gate that exploits cross gain modulation and crosspolarization rotation in a single semiconductor optical amplifier (SOA). Since the interacting signals are counterpropagating in the SOA, they can be set at the same wavelength. Photonic processing improves the speed of the optical networks by reducing the packet latency time to the time-of-flight in the nodes. Digital comparison and full-addition are key functionalities for the processing of the packet labels. Integrated realizations are crucial, thus, SOAs represent a suitable mean both because they allow hybrid integrated solutions and fast operation speed. The performances of the basic gate, the comparator, and the full adder are investigated both in terms of bit error rate and eye opening. To the best of our knowledge this is the first time it is reported on the implementation of an all-optical comparator able to compare patterns longer than 1 bit. Previous works demonstrate the comparison of 1 bit patterns. Only few works report on an all-optical full adder implementation, but with different schemes. In our implementation, sum and carry out do not depend directly on the carry in, thus potentially improving the output signal quality when cascading multiple full adders.

- by Luca Poti and +1
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- Quantum Physics, Nonlinear Optics, Process Improvement, Time of Flight

In this paper, we address accurate computation of complex propagation constants and field distributions of different modes, in general, lossless and lossy optical dielectric waveguides. Using the vector finite-element formulation of the beam propagation method combined with the imaginary distance propagation technique, sequence of both the guided and leaky modes can be accurately calculated. To show the versatility and numerical precision of the proposed technique, we compute the modes of three different three-dimensional (3-D) waveguide structures and compare the results against those of other, different, vector formulations. Further, we present the design of a higher order mode filtering device, based on a 3-D leaky mode optical waveguide.

- by Salah Obayya
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- Distributed Computing, Optics, Medical Imaging, Fiber Optics

Studies handling the lights and the colors as key components of computation attracted the scientists and engineers since these studies are potentially applicable to the signal processing through optical interconnections between electronic devices. Here, a novel optical computing model is proposed by modifying the known optical parallel logic gates, after employing the printed colors as the input/output data, instead of shadowgram images projected on a screen. The proposed approach allows spontaneous and parallel Boolean operations by simply overlaying the colors printed on films or duplicating the prints on papers. By setting a limited number of color prototypes with known CIELAB color coordinates, prediction of color changes due to duplicated color printing and/or film-on-paper overlaying of the printed colors was performed through Boolean “AND” operation and their experimental confirmation after actual color reading was also performed. Furthermore, possible applications of this CIELAB-coded printable logic gate system in natural computing and development of novel color barcodes were discussed.

- by Tomonori Kawano
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- Mathematics, Applied Mathematics, Mathematics of Cryptography, Algebra

The current major limiting factor in digital optical computing is a fast, efficient, cascadable optical switch with which to build computers. Candidates are not limited to the well known semiconductors and fabrication methods of electronics. A novel facility to evaluate candidate devices has been constructed. Multiline and tunable femtosecond and picosecond laser systems, as well as frequency mixing systems, are used as light sources. The facility has at least picosecond source capability from 200 nm to 2 micrometers. The switch transfer function is evaluated in a pump probe system with femtosecond and picosecond autocorrelators to measure dispersion, an optical multichannel analyzer to measure absorption, a CCD or pyroelectric camera system to measure mode modification, and a multidetector system to measure switching energy and insertion loss both in absorption and in reflection. The switch or switching array under test is mounted in a six-axis micropositioner system with a 0-20 goniometer; x, y, and z translators; and a tilt goniometer. Initial experiments on nonlinear interface optical switches are encouraging, as the selected broad bandwidth media has strong nonlinearity.

- by Joseph Osman
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- Nonlinear Optics, Optical Switch, Optical switching, Mixing

As in any discipline, in Computer Engineering, students start learning the basic concepts of the discipline in their first year through an Introduction to Computer Engineering course. The topics toughed in this course can be grouped into two. The first group includes simple concepts like binary numbering system, hard disk, memory, and I/O devices. In the second group, an introduction to the courses that they will take in the next semesters of the program which includes programming, networking, software engineering, artificial intelligence and database systems. The main objective of this course is to give an introduction about the general concepts of the field to the first year Computer Engineering students and prepare them to understand the connections between them for their future studies.

Optical sensing, e.g., computer vision, provides a very compelling approach to solving a number of technological challenges for developing affordable, useful, and reliable robotic products. We describe key advancements in the field consisting of three core technologies for Visual Pattern Recognition (ViPR), Visual Simultaneous Localization and Mapping (vSLAM), and a low-cost solution for localization using optical beacons (NorthStar).

There is a need for a processor to perform real-time automatic target classification (ATC) that is compact and consumes little electrical power. Optical processors have the potential to provide the needed computational power in a small package. Substantial efforts have been expended in the development of spatial light modulators (SLMs) to meet the ATC requirements, but performance achieved thus far is still lacking. A new class of optical devices, spatial light rebroadcasters (SLRs) have been developed recently with potential performance far exceeding current SLMs. Instead of modulating the input light field, SLR absorbs the incident radiation and re-emits when triggered to do so. The triggering can be accomplished with an optical signal which also carries spatial information. The storage capability and the relationship between the intensities of the incident (input), triggering (readout) and emitted (output) radiations can be used to perform parallel processing of two-dimensional s...

- by Nikola Subotic
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- Signal Processing, Parallel Processing, Integrated Optics, Artificial Intelligent

We show that the Fresnel field at a fraction of the Talbot distance behind a complex transmittance grating is conveniently described by a matrix operator. We devote special attention to a discrete-type grating, whose basic cell (of length d) is formed with a finite number (Q) of intervals of length d/Q, each with a constant complex transmittance. Ignoring the physical units of the optical field, we note that the transmittance of the discrete grating and its Fresnel field belong to a common Q-dimensional complex linear space (V Q ). In this context the Fresnel transform is recognized as a linear operator that is represented by a Q ϫ Q matrix. Several properties of this matrix operator are derived here and employed in a discussion of different issues related to the fractional Talbot effect. First, we review in a simple manner the field symmetries in the Talbot cell. Second, we discuss novel Talbot array illuminators. Third, we recognize the eigenvectors of the matrix operator as discrete gratings that exhibit self-images at fractions of the Talbot distance. And fourth, we present a novel representation of the Fresnel field in terms of the eigenvectors of the matrix operator.

- by Juan Ibarra
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- Optical computing, Optical Signal Processing, Diffractive optics

econvolution of three-dimensional (3-D) fluorescence microscopy images using computational restoration techniques has attracted great interest in the past decades [1]-[3]. Fluorescence microscope imaging properties and measurement imperfections distort the original 3-D image and reduce the maximal resolution obtainable by the imaging system, thereby restricting the quantitative analysis of the 3-D specimen [4]. Deconvolution is an operation that mitigates the distortion created by the microscope. The problem is often ill-posed, since little information on the imaging system is available in practice [5]. In this article, we present an overview of various deconvolution techniques on 3-D fluorescence microscopy images. We describe the subject of image deconvolution for 3-D fluorescence microscopy images and provide an overview of the distortion issues in different areas. We introduce a brief schematic description of fluorescence microscope systems and provide a summary of the microscope point-spread function (PSF), which often creates the most severe distortion in the acquired 3-D image. We discuss our ongoing research work in this area. We give a brief review of performance measures of three-dimensional (3-D) deconvolution microscopy techniques and summarize numerical results using simulated data, and then we present results obtained from the real data.

- by Arye Nehorai
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- Mechanical Engineering, Image Processing, Microscopy, Statistical Analysis
- by Hamid R. Arabnia
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- Circuits and Systems, Reversible Logic, Optical computing, Low Power

In recent years, reversible logic has emerged as a promising computing paradigm having application in low-power CMOS, quantum computing, nanotechnology and optical computing. Optical logic gates have the potential to work at macroscopic (light pulses carry information), or quantum (single photons carry information) levels with great efficiency. However, relatively little has been published on designing reversible logic circuits in all-optical domain. In this paper, we propose and design a novel scheme of Toffoli and Feynman gates in all-optical domain. We have described their principle of operations and used a theoretical model to assist this task, finally confirming through numerical simulations. Semiconductor optical amplifier (SOA)-based Mach–Zehnder interferometer (MZI) can play a significant role in this field of ultra-fast all-optical signal processing. The all-optical reversible circuits presented in this paper will be useful to perform different arithmetic (full adder, BCD adder) and logical (realization of Boolean function) operations in the domain of reversible logic-based information processing.

Optical computed tomography (optical-CT) of 3D radiation dosimeters is a promising avenue for delivering an economic and reliable quality control of radiotherapy treatments such as intensity modulated radiotherapy, brachytherapy and stereotactic radiosurgery. The main problems in transferring 3D dosimeters to clinical setting have been in (1) the complexity of manufacture and behaviour of 3D dosimeters and (2) time-consuming readout and analysis of 3D dosimeters. This paper addresses the readout problem by showing that fast (20 min tomography scan), precise (projection absorbance signal-to-noise ratio is greater than 100:1 across the absorbance range 0.2 to 1.5) and accurate (good linearity in the calibration curve) measurements are possible using a novel method of optically scanning a laser beam across the 3D dosimeter.

- by Simon Doran
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- Biomedical Engineering, Radiosurgery, Brachytherapy, Radiation Dosimetry

Eigenvalue computation is essential in many fields of science and engineering. For high performance and real-time applications, this may need to be done in hardware. This paper focuses on the exploration of hardware architectures which compute eigenvalues of symmetric matrices. We propose to use the Approximate Jacobi Method for general case symmetric matrix eigenvalue problem. The paper illustrates that the proposed architecture is more efficient than previous architectures reported in the literature. Moreover, for the special case of 3 × 3 symmetric matrices, we propose to use an Algebraic Method. It is shown that the pipelined architecture based on the Algebraic Method has a significant advantage in terms of area.

There are three interdependent factors that drive our software development processes: interval, quality and cost. As market Dressures continue to demand new features ever more months. network, consisting of circuit packs, ASICs, software units, and a craft terminal. Total head count for this release was 180 people and the development project lasted for 19 We conclude with lessons learned from the case study and resulting ongoing improvement activities.

- by Dewayne E Perry
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- Software Engineering, Project Management, Computer Networks, Quality Improvement

In this paper, we study the performance of multihop free-space optical (FSO) wireless systems over turbulenceinduced fading channels. The analysis is carried out for systems employing amplify-and-forward (AF) or decode-and-forward (DF) relays and for turbulence channels which can be modeled by the Gamma-Gamma distribution. An exact analytical expression for the end-to-end outage probability of AF systems is obtained, while a closed-form expression of DF systems is derived. The average bit-error probability of a dual-hop FSO system employing a DF relay is studied as a special case. Numerical examples are also presented to illustrate the proposed analysis and to further investigate the effects of the turbulence severity on the multihop FSO systems' performance.

- by Theodoros Tsiftsis
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- Optics, Medical Imaging, Fiber Optics, Turbulence

In this paper, we study a class of VLSI organizations with optical interconnects for fast solutions to several image processing tasks. The organization and operation of these architectures are based on a generic model called OMC, which is proposed to understand the computational limits in using free space optics in VLSI parallel processing systems. The relationships between OMC and shared memory models are discussed in this paper. Also, three physical implementations of OMC are presented. Using OMC, we present several parallel algorithms for fine grain image computing. We categorize our results in the following order. First, we present a set of processor efficient optimal O(log N) algorithms and a set of constant time algorithms for finding geometric properties of digitized images. Finally, we focus on special purpose designs tailored to meet both the computation and communication needs of problems such as those involving irregular sparse matrices.

Trapped and laser-cooled ions are increasingly used for a variety of modern high-precision experiments, for frequency standard applications, and for quantum information processing. Therefore laser cooling of trapped ions is reviewed, the current state of the art is reported, and several new cooling techniques are outlined. The principles of ion trapping and the basic concepts of laser cooling for trapped atoms are introduced. The underlying physical mechanisms are presented, and basic experiments are briefly sketched. Particular attention is paid to recent progress by elucidating several milestone experiments. In addition, a number of special cooling techniques pertaining to trapped ions are reviewed; open questions and future research lines are indicated.