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Barrera-Gonzalez, Claudia Patricia. "Variable swing optimal parallel links minimal power, maximal density for parallel links /." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 120 p, 2009. http://proquest.umi.com/pqdweb?did=1818417501&sid=11&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Sekar, Deepak Chandra. "Optimal signal, power, clock and thermal interconnect networks for high-performance 2d and 3d integrated circuits." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26562.
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Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009.<br>Committee Chair: Meindl, James; Committee Co-Chair: Davis, Jeffrey; Committee Member: Callen, Russell; Committee Member: Gaylord, Thomas; Committee Member: Kohl, Paul; Committee Member: Mukhopadhyay, Saibal. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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CELLA, FEDERICA. "Optimal genetic circuit design for mammalian synthetic biology applications." Doctoral thesis, Università degli studi di Genova, 2021. http://hdl.handle.net/11567/1045583.
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Synthetic biology combines biology and engineering to redesign living organisms by conferring them new properties. Synthetic biologists harness the power of nature to solve problems in medicine, manufacturing, and agriculture and use engineering principles to control and perturb cell pathways to gather novel insights into biological functions. Specifically, the programming of new functions into mammalian cells has tremendous application in research and medicine. The rapid advances in the ability to synthesize DNA and RNA have increased our understanding of gene function and regulation and have enabled the expansion of genetic parts available for programming cell biology. Genetic parts can be multiplexed to build complex genetic circuits to (i) confer new functions to the host cells, (ii) regulate endogenous pathways, or (iii) sense inputs of interest to actuate a cellular response. This thesis focuses on the optimization of genetic circuit design for mammalian synthetic biology applications. It covers the need for additional regulatory tools for tight spatiotemporal control of gene expression and cell response and the need for a better understanding of how regulation processes work in cells. Finally, it explores strategies to select biologically relevant inputs for sensor-actuator devices that control cell fate.
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Noble, Christopher Aaron. "Analytical and Numerical Techniques for the Optimal Design of Mineral Separation Circuits." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/23224.
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The design of mineral processing circuits is a complex, open-ended process. While several tools and methodologies are available, extensive data collection accompanied with trial-and-error simulation are often the predominant technical measures utilized throughout the process. Unfortunately, this approach often produces sub-optimal solutions, while squandering time and financial resources. This work proposes several new and refined methodologies intended to assist during all stages of circuit design. First, an algorithm has been developed to automatically determine circuit analytical solutions from a user-defined circuit configuration. This analytical solution may then be used to rank circuits by traditional derivative-based linear circuit analysis or one of several newly proposed objective functions, including a yield indicator (the yield score) or a value-based indicator (the moment of inertia). Second, this work presents a four-reactor flotation model which considers both process kinetics and machine carrying capacity. The simulator is suitable for scaling laboratory data to predict full-scale performance. By first using circuit analysis to reduce the number of design alternatives, experimental and simulation efforts may be focused to those configurations which have the best likelihood of enhanced performance while meeting secondary process objectives. Finally, this work verifies the circuit analysis methodology through a virtual experimental analysis of 17 circuit configurations. A hypothetical electrostatic separator was implemented into a dynamic physics-based discrete element modeling environment. The virtual experiment was used to quantify the selectivity of each circuit configuration, and the final results validate the initial circuit analysis projections.<br>Ph. D.
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Niewenhuis, Benjamin T. "A Logic Test Chip for Optimal Test and Diagnosis." Research Showcase @ CMU, 2018. http://repository.cmu.edu/dissertations/1176.
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The benefits of the continued progress in integrated circuit manufacturing have been numerous, most notably in the explosion of computing power in devices ranging from cell phones to cars. Key to this success has been strategies to identify, manage, and mitigate yield loss. One such strategy is the use of test structures to identify sources of yield loss early in the development of a new manufacturing process. However, the aggressive scaling of feature dimensions, the integration of new materials, and the increase in structural complexity in modern technologies has challenged the capabilities of conventional test structures. To help address these challenges, a new logic test chip, called the Carnegie Mellon Logic Characterization Vehicle (CM-LCV), has been developed. The CM-LCV utilizes a two- dimensional array of functional unit blocks (FUBs) that each implement an innovative functionality. Properties including fault coverage, logical and physical design features, and fault distinguishability are shown to be composable within the FUB array; that is, they exist regardless of the size and composition of the FUB array. A synthesis ow that leverages this composability to adapt the FUB array to a wide range of test chip design requirements is presented. The connection between the innovative FUB functionality and orthogonal Latin squares is identified and used to analyze the universe of possible FUB functions. Two additional variants to the FUB array are also developed: heterogenous FUB arrays utilize multiple FUB functions to improve the synthesis ow performance, while pipelined FUB arrays incorporate sequential circuit elements (e.g., ip- ops and latches) that are absent from the original combinational FUB array. In addition to the design of the CM-LCV, methods for testing it are presented. Techniques to create minimal sets of test patterns that exhaustively exercise each FUB within the FUB array are developed. Additional constraints are described for the heterogenous and pipelined FUB arrays that allow these techniques to be applied for both variant FUB arrays. Furthermore, a simple built-in self test (BIST) scheme is described and applied to a reference design, resulting in a 88.0% reduction in the number of test cycles required without loss in fault coverage. A hierarchical FUB array diagnosis methodology (HFAD) is also presented for the CM- LCV that leverages its unique properties to improve performance for multiple defects. Experiments demonstrate that this HFAD methodology is capable of perfect accuracy in 93.1% of simulations with two injected faults, an improvement on the state-of-the-art commercial diagnosis. Additionally, silicon fail data was collected from a CM-LCV manufactured using a 14nm process by an industry partner. A comparison of the diagnosis results for the 1,375 fail logs examined shows that the HFAD methodology discovers additional defects during multiple defect diagnosis that the commercial tool misses for 40 of the diagnosed fail logs. Examination of these cases shows that the additional defects found by the HFAD methodology can result in improved diagnosis confidence and more precise descriptions of the defect behavior(s). The contributions of this dissertation can thus be summarized as the description of the design, test, and diagnosis of a new logic test chip for use in yield learning during process development. This CM-LCV can be adapted to meet a wide range of test chip requirements, can be efficiently and rigorously tested, and exhibits properties that can be used to improve diagnosis outcomes. All of these claims are validated through both simulated experiments and silicon data.
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Cohn, Amy Mainville, Michael J. Magazine, and George G. Polak. "An Optimal Algorithm for Integrating Printed Circuit Board Manufacturing Problems." Massachusetts Institute of Technology, Operations Research Center, 2000. http://hdl.handle.net/1721.1/5209.
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Printed circuit boards appear in a wide array of products and thus their production is crucial to the contemporary electronics industry. A global approach to planning the complex and multi-stage production process is currently intractable. Nonetheless,significant improvements can be made by integrating closely related elements within the planning process. We focus here on the integration of two key problems -- product clustering and machine setup. In the product clustering problem, board types with similar component requirements are clustered together for assembly under a common configuration of the pick-and-place machine. In the machine setup problem, an optimal configuration of the pick-and-place machine is found for each of these clusters. In practice and in the literature, the product clustering and machine setup problems are typically solved sequentially. By instead solving the two problems simultaneously, we are able to find an optimal tradeoff between processing and setup times. We present the Integrated Clustering and Machine Setup model as a set partitioning problem. We describe a branch-and-price algorithm for solving this exponentially large problem. We introduce a rank-cluster-and-prune, a method for solving the imbedded pricing problems by combinatorial search, and conclude with computational results.
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Tsai, Wei Kang. "Optimal quasi-static routing for virtual circuit networks subjected to stochastic inputs." Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/15077.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1986.<br>MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING<br>Bibliography: leaves 111-114.<br>by Wei Kang Tsai.<br>Ph.D.
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Pimenta, Tales Cleber. "Optimal design of VLSI structures with built-in self test based on reduced pseudo-exhaustive testing." Ohio : Ohio University, 1992. http://www.ohiolink.edu/etd/view.cgi?ohiou1173755841.
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Vilamot, Raphaël. "Optimisation de la configuration magnétique d'un propulseur à effet Hall par résolution du problème magnétostatique inverse." Phd thesis, Toulouse, INPT, 2012. http://oatao.univ-toulouse.fr/14668/1/vilamot.pdf.
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Les travaux effectués lors de cette thèse portent sur l'optimisation de la configuration magnétique des propulseurs à effet Hall. Ceci regroupe deux objectifs: d'une part la réalisation d'un propulseur à effet Hall dont la topologie magnétique est entièrement paramétrable, ce qui constituera un outil précieux pour l'étude de l'impact du champ magnétique sur le fonctionnement du propulseur et d'autre part, l'étude de moyen de conception rationalisée de circuits magnétiques pour ces mêmes propulseurs. Le premier sujet a conduit à la réalisation du PPS-Flex, un propulseur proposant une structure de circuit magnétique innovante offrant un grand nombre de degrés de liberté en termes de réglage du champ magnétique produit. La deuxième thématique a quant à elle été abordée en s'appuyant sur des méthodes d'optimisation (paramétrique et topologique) permettant d'aboutir à un circuit magnétique optimal pour un ou plusieurs critères de conception (fidélité du champ magnétique généré, minimisation de la masse, du volume total, etc.)
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Sergent, Aaronn. "Optimal Sizing and Control of Battery Energy Storage Systems for Hybrid-Electric, Distributed-Propulsion Regional Aircraft." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1595519141013663.
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Ghazizadeh, Ali. "Optimum mounting of electronic circuit boards for components and circuits survivability." Thesis, University of Ottawa (Canada), 1994. http://hdl.handle.net/10393/6936.
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Electronic circuit boards are employed in demanding environments (e.g. satellite, aerospace, marine, automobile, etc.) where the board and mounted components are exposed to vibration of varying amplitude and frequencies. Optimum mounting and component placement to reduce the effect of vibration on the equipment may prolong the service life of the system and reduce costly down time. Electronic boards are often mounted on four rigid support legs. Their vibration is a function of the location of the support legs, and board physical specifications such as length, width, weight, and placement of the components mounted on them. In this study, plate vibration analysis is employed to find the board's free vibration. With the help of nonlinear optimization methods, optimum mounting of circuit boards are investigated. Square board has a better performance than any other board shape. A table of suitable support points will be introduced outlining optimum support points for eight rectangular shapes. For each of these shapes a graph of unsuitable regions is provided to help the designer to avoid placing delicate components over those regions of the plate. Furthermore, the tabulated results can eliminate the need for optimization in non-critical circuit boards or determine a good starting point for optimization. (Abstract shortened by UMI.)
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Bakir, Muhannad S. "Sea of Leads electrical-optical polymer pillar chip I/O interconnections for gigascale integration." Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04082004-180010/unrestricted/bakir%5Fmuhannad%5Fs%5F200312%5Fphd.pdf.
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Iqbal, Muzammil. "Intrachip global communication evaluation of challenges and optical solutions /." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 209 p, 2007. http://proquest.umi.com/pqdweb?did=1251904841&sid=2&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Chou, Jerry. "A new network architecture for future optical networks coarse optical circuit switching by default, rerouting over circuits for adaptation /." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3359733.
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Thesis (Ph. D.)--University of California, San Diego, 2009.<br>Title from first page of PDF file (viewed July 23, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 125-132).
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Benlamine, Raouf. "Etude et réalisation d'une machine électrique à forte densité de couple et fort rapport de sur-couple pour des applications de traction automobile." Thesis, Besançon, 2015. http://www.theses.fr/2015BESA2014/document.
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Le contexte sociétal et environnemental en France et en Europe durant ces dernières années est largement favorable à l’électrification des moyens de transports, principalement les véhicules, afin de réduire les émissions de CO2. Les pouvoirs publics déploient d’importants efforts afin de rendre les véhicules électrifiés plus accessibles aux citoyens, en octroyant des primes conséquentes lors de l’achat de véhicules « propres ». De leur côté, les constructeurs automobiles cherchent à diminuer le coût des véhicules électriques et hybrides en proposant des solutions techniques pouvant réduire le coût de fabrication des organes, principalement les batteries, les moteurs thermiques et électriques, tout en assurant des performances élevés. L’objectif principal de cette thèse est d’étudier et de réaliser une machine électrique répondant à un cahier des charges très contraignant en termes d’encombrement axial et de densité de couple pour une application comme moteur de traction d’un véhicule hybride. De plus, cette machine doit être innovante, robuste et dont le procédé de fabrication est automatisable et à faible coût. Ainsi, un état de l’art élargi sur les différentes machines électriques a été effectué. En fonction des exigences liées à notre application, une machine à flux axial à aimants permanents enterrés à bobinage concentrique a été choisie.Initialement, un modèle analytique simplifié a été établi et couplé à un outil d’optimisation. Les paramètres géométriques et électriques obtenus ont été alors réajustés en utilisant un modèle numérique basé sur les éléments finis 3D. Différentes modifications ont été apportées à cette machine initiale en raison de l’évolution du cahier des charges des performances et des contraintes géométriques. Les grandeurs électromagnétiques telles que le couple et la puissance ont été analysées pour différents points de fonctionnement. Les pertes dans les aimants permanents ont été calculées en développant un modèle numérique hybride basé sur les différences finies 3D, réduisant ainsi le temps de calcul comparativement aux éléments finis 3D. Afin de valider les différents résultats obtenus, un prototype de la machine a été réalisé. Cette machine a également été modélisée en utilisant les Circuits Equivalents Magnétiques quasi-3D. Ce modèle semi-analytique est générique par rapport aux dimensions géométriques et électriques, avec une discrétisation adaptative. De plus, les effets de denture et de saturation sont pris en compte. Les inductions magnétiques, les flux magnétiques et le couple électromagnétique ont pu être obtenus avec ce modèle, en assurant une bonne précision et un temps de calcul réduit comparativement aux éléments finis 3D<br>The societal and environmental context in France and Europe during the last few years has been largely favorable to the electrification of transportation means, mainly vehicles, in order to reduce CO2 emissions. The authorities are working hard to make the electrified vehicles more affordable, by providing substantial premiums during the purchase of “clean” vehicles. For their part, the automakers are looking to reduce the cost of electric and hybrid electric vehicles by offering technical solutions that can reduce the manufacturing cost of the car components, mainly batteries, thermal and electric motors, while ensuring high performances. The main objective of this thesis is to study and realize an electric machine, which satisfies very restrictive specifications in terms of axial size and torque density in order to be used as a traction motor for a hybrid electric vehicle. In addition, this machine must be innovative, with a high reliability, low cost and automated manufacturing process. Thus, a state of art about the various electric machines has been achieved. Depending on the requirements of our application, an axial flux machine with buried permanent magnets and concentrated winding has been selected. Initially, a simplified analytical model has been developed and coupled to an optimization tool. The obtained geometrical and electrical parameters have been adjusted using a numerical model based on the 3D finite element. Various modifications have been applied to the initial machine due to the modification of the geometrical and performance specifications. Electromagnetic performances such as torque and power have been analyzed for various operating points. Losses in the permanent magnets have been calculated using a hybrid numerical 3D model based on the finite difference and finite element, which allows to reduce the computation time compared to transient 3D finite element. In order to validate the different results, a prototype of the machine has been realized. This machine has also been modeled using a quasi-3D magnetic equivalent circuits. This semi-analytical model is generic regarding the geometrical and electrical parameters, with an adaptive discretization. Furthermore, the saturation and the slotting effects have been taken into account. The magnetic flux density, the flux linkage and the electromagnetic torque have been calculated with this model, ensuring high accuracy and reduced time computation compared to 3D finite element
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Safa, Mohamad. "Sur la planification des reseaux telephoniques avec acheminement adaptatif." Toulouse 3, 1986. http://www.theses.fr/1986TOU30087.
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Le but du travail presente a ete de mettre en evidence l'importance de l'adaptation de la structure des reseaux au type de commande envisage (politiques s'adaptant en temps reel aux variations de charge du reseau). Partant d'un modele de type fluide anterieurement developpe, une adaptation permettant de caracteriser l'effet occasionne par l'introduction de politiques de commande temps reel est proposee. Le modele propose est utilise a des fins de planification des reseaux. Un algorithme classique de directions admissibles est adopte pour prendre en compte certaines contraintes de modularite. Plus interessant du point de vue facilite de mise en oeuvre, un algorithme base sur une recherche stochastique dans l'espace discret des structures admissibles est developpe (recuit simule)
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Peres, Wesley. "Contribuições ao estudo de recomposição fluente de sistemas elétricos de potência." Universidade Federal de Juiz de Fora, 2012. https://repositorio.ufjf.br/jspui/handle/ufjf/1784.
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Previous issue date: 2012-03-05<br>Este trabalho apresenta uma metodologia baseada em Fluxo de Potência Ótimo (FPO) e Análise de Sensibilidade para a definição da configuração mínima de rede necessária para garantir, com segurança, o processo de recomposição fluente de corredores radiais de transmissão. Nos instantes iniciais de recomposição, devido à baixa capacidade de geração que o sistema se encontra, uma estratégia importante consiste em elevar a Capacidade de Curto Circuito das barras. Neste sentido, a metodologia proposta baseia-se na incorporação, na função objetivo do FPO, da maximização da potência de curto circuito das barras. Para tanto, uma Análise de Sensibilidade é realizada a cada iteração do processo iterativo para determinar os fatores de ponderação de alocação associados à impedância equivalente permitindo a inclusão no FPO da maximização da potência de curto circuito das barras. Na metodologia proposta os reatores que mais reduzirem a impedância receberão menores fatores de ponderação de alocação. Adicionalmente, o FPO contempla a modelagem das máquinas síncronas, curva de capabilidade e o estudo de cada cenário de recomposição em regime permanente, pré e pós rejeição de carga. O programa desenvolvido em MATLAB é utilizado para a simulação de corredores de recomposição fluente do sistema elétrico brasileiro. Os resultados obtidos apontam para uma ferramenta eficaz ao estudo de recomposição fluente.<br>This work presents a methodology based on Optimal Power Flow (OPF) and Sensitivity Analysis to define a minimum network configuration for a power system fluent restoration taking security issues into account. At this early restoration stage, the system has low Short-Circuit Capacity due to the low generation capacity. An important strategy is to increase the Short Circuit Capacity at this operation stage through search network configurations with low bus equivalent impedance. In this work, the Short-Circuit Capacity is incorporated in the objective function of the OPF formulation by using sensitivity analysis which yields lowest allocation factors for more suitable reactors to reduce the equivalents impedances. The proposed OPF takes into account the synchronous machine model, the capability curves and the set of overvoltage critical restoration scenarios following load rejection. The restoration scenarios are represented at steady state prior and after load rejection. The computational tool is developed in the MATLAB platform and it is used to conduct case studies for fluent restoration branches of Brazilian Electric System. The results show that the proposed methodology is effective.
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Cove, Stephen E. "A 10 gigabit per second limiting amplifier with 40dB gain and 7 GHz bandwidth for SONET OC-192 applications." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0009921.
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Chiloiro, Giuseppe Marco. "Virtual coach for super sports cars: a possible AI application." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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The dream of the human being has always been to reach the perfection.
This is true for life in general, but also for sports competitions including motorsport.
In car racing, the optimum is represented by the perfect lap, performed by the driver in the minimum possible time, following the ideal race line with the appropriate velocity.
However, due to the intrinsic nature of human being this is unfeasible and the only way to get as close as possible to the perfection is to rely on technology and artificial intelligence.
Focusing on motorsport, the actual knowledge of vehicle dynamics and the development of optimization techniques can help in reaching great improvements in terms of race performance.
This is exactly the objective of this thesis in which the implementation of a virtual coach for super sports cars has been carried out, in order to provide useful suggestions to the driver during and after the performance.
In particular, the algorithm on which the virtual coach is based, computes the ideal race line and the optimal velocity in every point, giving also an accurate estimation of the best reachable lap time.
The virtual coach is able to adapt to each super sports car and circuit, since the vehicle and racetrack models are generated starting from the physical parameters introduced by the user as inputs to the algorithm.
The optimization of the race line is performed by solving the minimum lap time problem through the optimal control theory and the optimal velocity is computed for each point of the ideal trajectory.
After the first lap, the algorithm associates the driver to a category level and shows which are the sectors of the circuit where a higher improvement is possible, adapting the targets in terms of lap time and velocity to the driver’s capabilities and allowing a step by step improving of the performances.
The algorithm has been tested on a large variety of vehicles and circuits, providing accurate results in terms of ideal race lines and velocities.
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Crowe, Craig A. "Optical SNS folding circuit design." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1995. http://handle.dtic.mil/100.2/ADA295419.
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Thesis (M.S. in Electrical Engineering) Naval Postgraduate School, March 1995.<br>Thesis advisor(s): Phillip Pace, Ron J. Pieper. "March 1995." Includes bibliographical references. Also available online.
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Pitwon, Richard Charles Alexander. "Pluggable optical connector interfaces for electro-optical circuit boards." Thesis, University of Plymouth, 2017. http://hdl.handle.net/10026.1/9825.
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A study is hereby presented on system embedded photonic interconnect technologies, which would address the communications bottleneck in modern exascale data centre systems driven by exponentially rising consumption of digital information and the associated complexity of intra-data centre network management along with dwindling data storage capacities. It is proposed that this bottleneck be addressed by adopting within the system electro-optical printed circuit boards (OPCBs), on which conventional electrical layers provide power distribution and static or low speed signaling, but high speed signals are conveyed by optical channels on separate embedded optical layers. One crucial prerequisite towards adopting OPCBs in modern data storage and switch systems is a reliable method of optically connecting peripheral cards and devices within the system to an OPCB backplane or motherboard in a pluggable manner. However the large mechanical misalignment tolerances between connecting cards and devices inherent to such systems are contrasted by the small sizes of optical waveguides required to support optical communication at the speeds defined by prevailing communication protocols. An innovative approach is therefore required to decouple the contrasting mechanical tolerances in the electrical and optical domains in the system in order to enable reliable pluggable optical connectivity. This thesis presents the design, development and characterisation of a suite of new optical waveguide connector interface solutions for electro-optical printed circuit boards (OPCBs) based on embedded planar polymer waveguides and planar glass waveguides. The technologies described include waveguide receptacles allowing parallel fibre connectors to be connected directly to OPCB embedded planar waveguides and board-to-board connectors with embedded parallel optical transceivers allowing daughtercards to be orthogonally connected to an OPCB backplane. For OPCBs based on embedded planar polymer waveguides and embedded planar glass waveguides, a complete demonstration platform was designed and developed to evaluate the connector interfaces and the associated embedded optical interconnect. Furthermore a large portfolio of intellectual property comprising 19 patents and patent applications was generated during the course of this study, spanning the field of OPCBs, optical waveguides, optical connectors, optical assembly and system embedded optical interconnects.
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Wolf, Alexander M. "Optical recording of neuronal circuit dynamics." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973392592.
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Wang, Fengtao. "Optical interconnects on printed circuit boards." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37133.
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The ever-increasing need for higher bandwidth and density is one of the motivations for extensive research on planar optoelectronic structures on printed circuit board (PCB) substrates. Among these applications, optical interconnects have received considerable attention in the last decade. Several optical interconnect techniques, such as free space, guided wave, board level and fiber array interconnects, have been introduced for system level applications. In all planar optoelectronic systems, optical waveguides are crucial elements that facilitate signal routing. Low propagation loss, high reliability and manufacturability are among the requirements of polymer optical waveguides and polymer passive devices on PCB substrates for practical applications. Besides fabrication requirements, reliable characterization tools are needed to accurately and nondestructively measure important guiding properties, such as waveguide propagation loss. In three-dimensional (3D) fully embedded board-level optical interconnects, another key challenge is to realize efficient optical coupling between in-plane waveguides and out-of-plane laser/detector devices.
Driven by these motivations, the research presented in this thesis focuses on some fundamental studies of optical interconnects for PCB substrates, e.g., developing low-loss optical polymer waveguides with integrated efficient out-of-plane couplers for optical interconnects on printed circuit board substrates, as well as the demonstration of a novel free-space optical interconnect system by using a volume holographic thin film. Firstly, the theoretical and experimental investigations on the limitations of using mercury i-line ultraviolet (UV) proximity photolithography have been carried out, and the metallization techniques for fine copper line formation are explored. Then, a new type of low-loss polymer waveguides (i.e., capped waveguide) is demonstrated by using contact photolithography with considerable performance improvement over the conventional waveguides. To characterize the propagation properties of planar optical waveguides, a reliable, nondestructive, and real-time technique is presented based on accurately imaging the scattered light from the waveguide using a sensitive charge coupled device (CCD) camera that has a built-in integration functionality. To provide surface normal light coupling between waveguides and optoelectronic devices for optical interconnects, a simple method is presented here to integrate 45° total internal reflection micro-mirrors with polymer optical waveguides by an improved tilted beam photolithography (with the aid of de-ionized water) on PCBs. A new technique is developed for a thin layer of metal coating on the micro-mirrors to achieve higher reflection and coupling efficiency (i.e., above 90%). The combination of the capped waveguide technique and the improved tilted UV exposure technique along with a hard reusable metal mask for metal deposition eliminates the usage of the traditional lift-off process, greatly simplifies the process, and reduces fabrication cost without sacrificing the coating quality. For the study of free-space optical interconnects, a simple system is presented by employing a single thin-film polymeric volume holographic element. One 2-spherical-beam hologram is used to link each point light source with the corresponding photodetector. An 8-channel free-space optical interconnect system with high link efficiency is demonstrated by using a single volume holographic element where 8 holograms are recorded.
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Bond, Steven Winfred. "Through-silicon circuit optical communications links." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/15390.
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Bystrov, Alexandre. "Optimal testing of multilevel logic circuits." Thesis, Edinburgh Napier University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300327.
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Ren, Qiu-shi. "Dynamic optical interconnection for integrated circuit chips /." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487687485810817.
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Crawley, David George. "Time optimal arithmetic for VLSI." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239081.
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STELLA, FEDERICA. "Hybrid superconductive-optical circuits integration." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2008. http://hdl.handle.net/2108/620.
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L’interazione di radiazione visibile con dispositivi elettronici è stato uno dei più interessanti argomenti di ricerca nel campo della fisica, dell’ingegneria elettronica e della scienza dei materiali nelle ultime quattro decadi. Come conseguenza la letteratura scientifica è cresciuta moltissimo. Le applicazioni hanno raggiunto un uso quotidiano e la diffusione a larga scala insieme alla ricerca di base e applicata stanno espandendosi ulteriormente. La maggior parte dei lavori in questo ambito sono stati realizzati su dispositivi elettronici il cui funzionamento era basato sull’impiego di materiali semiconduttori, dielettrici o metallici.
Lo scopo del presente lavoro di tesi è principalmente lo studio dell’interazione di luce visibile con sistemi superconduttori. Più in particolare un obiettivo specifico di questo studio è stata l’analisi delle possibili tecniche sperimentali che permettano da un lato l’integrazione di strutture superconduttrici planari e di guide d’onda ottiche sul medesimo substrato, dall’altro un miglioramento nell’accoppiamento della luce, proveniente da una sorgente posta a temperatura ambiente, su questi substrati raffreddati alla temperatura dell’elio liquido (4.2° K).
Come strumento per testare la qualità del processo di integrazione e della manipolazione della luce sono stati utilizzati dispositivi superconduttori planari basati sul tunneling superconduttivo e sull’effetto Josephson.
L’investigazione è stata rivolta verso strutture superconduttive basate sulla tecnologia del trilayer di Niobio e Alluminio, e verso guide d’onda canale sintetizzate per mezzo della tecnologia Sol-Gel. E’ stato in questo modo sviluppato un processo che ha reso possibile lo studio dell’effetto di luce rossa sulle strutture tunnel superconduttrici. Tale effetto è stato analizzato in termini di superconduttività al nonequilibrio.<br>The interaction of optical wavelength radiation with electron devices has been one of the most appealing research topics in physics, electrical engineering and material science over the past four decades. As a consequence the scientific literature has grown to the level that it can hardly be contained even in excellent books and reviews. The applications have reached every day’s use and large scale diffusion and the research at fundamental and applied commercial level is still expanding. Most of the work described in the previous paragraph has been based on electron devices relying on the use of semiconducting, dielectric or metallic materials.
The purpose of the present thesis work is mainly the investigation of the interaction of visible light with superconducting systems. In particular, a specific aim of the present work is just the investigation of possible experimental techniques that could lead both to an integration of planar superconductive structures and optical waveguides on the same chip and, at the same, an improvement of the ease in the coupling of light from room temperature to cryogenic environments. We will use as tools for testing the quality of our integration techniques and light manipulation essentially superconducting planar devices based on superconductive tunnelling and Josephson effect.
The technological feature of the present project demanded integration of superconductive planar devices with optical planar circuits. We decided to direct the investigation toward all niobium trilayer technology and Sol-Gel synthesised optical channel waveguides. A process has been developed which enabled us to study the effect of red light on tunnelling structures. The results have been analysed in terms of nonequilibrium superconductivity.
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Smith, Craig Scott. "Implementing pipelined circuit switching on the PICA aligned offset cube topology." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/13362.
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Hasan, Mehedi. "Coherent Optical & Electro-Optical Signal Processor Circuit Architectures for Photonic Integration." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/41580.
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The capacity of optical communications networks continues to grow unabated. Applications for streaming video, social networking and cloud computing, are driving exponential growth of the traffic carried over the world’s ICT networks, which has been sustained thus far through the proliferation of datacenters and efficient, effective use of existing optical fibre. To meet increasing capacity demands requires increasingly sophisticated modulation formats and spectral management to achieve effective use of the available spectrum provided by an optical fibre. Moreover, the technology developed for optical communications is finding broader application to other sectors such as data centres, 5&6 G wireless; lidar and radar.
Ultimately, some essential signal processing functions must occur at speeds beyond purely electronic means even when accounting for anticipated technological development. The option is to perform signal processing in the optical domain. Optical signal processors are fundamentally analog and linear in nature. To provide high performance, an analogue processor must be well controlled in a way analogous to the numerous and sophisticated controllers employed by the process industry. Consequently, a further extension of control to deeper levels within the physical layer reaching the optical layer will be necessary. For example, current reconfigurable optical add-drop multiplexers are coloured and directional and the wavelength division multiplexing channel grid, transponders modulation format, and the routing are all fixed. Through optimization of the interface between the physical components, sensors, and processors elastic optical network technology can be achieved by employing colour-, direction-, contention-, grid-less, filter-, gap-less reconfigurable optical add-drop multiplexers, flexible channels centre frequencies and width, flexible sub-carriers in super-channels, flexible modulation formats and forward error control coding transponders, and impairment-aware wavelength routing and spectral assignment.
The aim of this thesis is to advance the state-of-the-art in photonic circuits and subsystems via proposing new architecture; study of the feasibility of photonic integration and, proof of concept implementations using available resources. The goal is to introduce new architectural concepts that make effective use of physical components and/or optical processors with reduced energy consumption, reduced footprint and offer speed beyond all-electronic implementations. The thesis presents four case studies based on one or more published papers and supplementary material that advance the goal of the thesis.
The first study presents a coherent electro-optic circuit architecture that generates N spatially distinct phase-correlated harmonically related carriers using a generalized Mach-Zehnder Interferometer with its N×1 combiner replaced by an N×N optical Discrete Fourier Transform. The architecture subsumes all Mach-Zehnder Interferometer-based architectures in the prior art given an appropriate selection of output port(s) and dimension N, although the principal application envisaged is phase-correlated subcarrier generation for next-generation optical transmission systems. The theoretical prediction is then verified experimentally using laboratory available photonic integrated circuit fabricated for other applications. Later on, a novel extension of the circuit architecture is introduced by replacing the optical Discrete Fourier Transform network using the combination of a properly chosen phase shifter and single MMI coupler. The second study proposes two novel architectures for an on-chip ultra-high-resolution panoramic spectrometer and presents their design, analysis, integration feasibility, and verification by simulation. The target application is to monitor the power of a wavelength division multiplexed signals in both fixed and flex grid over entire C-band with minimum scan time and better than 1 GHz frequency accuracy. The two architectures combine in synchrony a scanning comb filter stage and channelized coarse filter. The fine filtering is obtained using a ring resonator while the coarse filtering is obtained using an arrayed waveguide grating with appropriate configuration. The fully coherent first architecture is optimised for compactness but relies on a repeatable fabrication processes to match the optical path lengths between a Mach-Zehnder interferometer and a multiple input arrayed waveguide grating. The second architecture is less compact than the first but is robust to fabrication tolerances as it does not require the path length matching. The third study proposes a new circuit architecture for single sideband modulation or frequency conversion which employs a cascade Mach-Zehnder modulator architecture departing from the orthodox dual parallel solution. The theoretical analysis shows that the circuit has 3-dB optical and 3-dB electrical advantage over the orthodox solution. The 3-dB electrical advantage increases the linear operating range of Mach-Zehnder modulator before RF amplifier saturation. An experimental verification of the proposed architecture is provided using an available photonic integrated circuit. The proposed circuit can also perform complex modulation. An alternative implementation based on polarization modulators is also described. The fourth study presents the theoretical modelling of a photonic generation of broadband radio frequency phase shifter. The proposed phase shifter can generate any phase without bound: the complex transmission of the phase shifter follows a trajectory that rotates on a unit circle and may encircle the origin any number of times in either direction, which has great utility in the tuning of RF-photonic systems. The proposed concept is then verified experimentally using off the shelf low frequency electronic components.
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Phang, Khoman S. "CMOS optical preamplifier design using graphical circuit analysis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ58961.pdf.
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Sato, Ken-ichi. "Future directions in optical networking technology development — Optical fast circuit switching and multilevel optical routing." IEEE, 2009. http://hdl.handle.net/2237/13986.
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Chu, Chong-nuen. "Efficient and optimal solutions for interconnect optimization /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Ramadass, Yogesh Kumar. "An energy optimal power supply for digital circuits." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/37922.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.<br>Includes bibliographical references (p. 96-98).<br>The energy efficiency of digital circuits continues to be a major factor in determining the size and weight of battery-operated electronics. Integration of more functionality in a single system has made battery longevity a major problem. Operating circuits at their minimum energy operating voltage (MEP) has been proposed as a solution for energy critical applications where performance is not a key constraint. This thesis explores the sensitivity of the MEP to operating conditions and motivates the need for continuous minimum energy tracking based on the energy savings possible. A circuit that can dynamically track the MEP of a digital circuit with varying load conditions and temperature is presented. A low power, voltage scalable DC-DC converter is also embedded within the chip. The proposed minimum energy tracking algorithm uses a novel approach to sense the energy consumed per operation. The energy sensing circuitry does not use high-resolution Analog-to-Digital converters or high gain amplifiers. The energy estimate is used in a slope tracking algorithm to track the minimum energy operating voltage. The minimum energy tracking loop along with a low-voltage DC-DC converter and test circuitry were fabricated in a 65nm CMOS process.<br>(cont.) The circuits are powered from an external 1.2V supply. The digital test circuitry was capable of operation at voltages as low as 0.25V. The tracking of the minimum energy operating voltage with change in workload and temperature was observed. The DC-DC converter was able to deliver load voltages between 0.25V and 0.7V with an efficiency > 78% at load power levels of the order of 1 0.1W and above.<br>by Yogesh Kumar Ramadass.<br>S.M.
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Safaei, Shabnam. "Quantum Optimal Control of Josephson Junction-Based Circuits." Doctoral thesis, Scuola Normale Superiore, 2009. http://hdl.handle.net/11384/85839.
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Guimarães, Murilo. "Circuito equivalente e extração de parametros em um amplificador optico a semicondutor." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259024.
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Orientadores: Evandro Conforti, Cristiano de Melo Galle<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e Computação<br>Made available in DSpace on 2018-08-09T14:44:31Z (GMT). No. of bitstreams: 1
Guimaraes_Murilo_M.pdf: 2868472 bytes, checksum: 35d629f44273794bf3425431f0abbade (MD5)
Previous issue date: 2007<br>Resumo: O advento das comunicações por fibras ópticas esteve intrinsecamente ligado aos lasers a diodo semicondutor. Posteriormente, principalmente na área de redes metropolitanas, iniciaram-se as aplicações envolvendo o amplificador óptico a semicondutor (SOA, em inglês). O SOA é muito similar ao laser a diodo semicondutor, pois também amplifica a luz incidente através da emissão estimulada, a qual advém da emissão pelos portadores elétricos da região ativa. Estes são bombeados na região ativa através da corrente elétrica injetada na porta elétrica do SOA. A similaridade não é completa devido ao fato do amplificador não possuir realimentação de luz através de uma cavidade óptica ressonante, uma vez que sua região ativa é terminada por faces anti-refletivas. Dessa forma, a luz é amplificada apenas em uma passagem pela região ativa do SOA, sendo também denominado neste caso, SOA-TW, ou de onda caminhante. Desta forma, fazendo-se uma analogia com circuitos, a diferença SOAlaser é semelhante à diferença amplificador-oscilador eletrônico. Devido a esta semelhança, o estudo desenvolvido no presente trabalho, sobre o comportamento da impedância do amplificador óptico a semicondutor, foi baseado em um modelo equivalente de circuito de microondas desenvolvido para o laser a diodo semicondutor. O comportamento da impedância do SOA, composto por seu encapsulamento e chip, é de extrema importância para o controle e aprimoramento de chaveamento eletro-óptico do SOA em redes de última geração. Visando ao aprofundamento deste estudo, análises teóricas a respeito do laser a diodo semicondutor e do amplificador óptico a semicondutor são apresentados. Em seguida, são apresentados os resultados experimentais, com a extração do circuito equivalente do SOA e sua montagem eletro-óptica, com a comparação entre as respostas experimentais e teóricas. Nas considerações finais discutem-se as sugestões para trabalhos futuros sobre o comportamento da impedância eletro-óptica do SOA<br>Abstract: The advent of communications using optical fiber was always connected, intrinsically, with the semiconductor diode laser. Later, in metropolitan optical networks, the semiconductor optical amplifier (SOA) was introduced to amplify up to eight channels in a WDM (wavelength division multiplex) system. The semiconductor optical amplifier and the semiconductor laser diode are similar since both of them amplify the input light through stimulated emission, which result from electric carriers that are pumped in the active layer through the injection current in the electrical gate in these devices. The similarity is not complete since the SOA has anti-reflection coatings at the end emission faces. Therefore, the light is amplified by the active layer only in one pass; in this case the SOA is called TW SOA (traveling wave SOA). Due to the similarity between the devices, the present study of the SOA impedance behavior was based in an equivalent model from researches about microwave circuits used in the literature to analyze semiconductor diode lasers. The SOA impedance behavior is given by the chip itself and its package; it is important to control and to improve the electrical-optical switch using the SOA for next generation networks. Looking for a deep knowledge about this research, theoretical analyses of the semiconductor diode lasers and SOA was presented in this research. After it, the experimental results are showed with the extraction of the SOA equivalent circuit and the electrical-optical assembly, and the comparison between the experimental and theoretical results was done. At the end of this work, some suggestions for future works are proposed regarding the behavior of the SOA electrical-optical impedance<br>Mestrado<br>Telecomunicações e Telemática<br>Mestre em Engenharia Elétrica
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SATO, Ken-ichi, Hiroshi HASEGAWA, and Takahiro OGAWA. "Optical Fast Circuit Switching Networks Employing Dynamic Waveband Tunnel." 電子情報通信学会, 2012. https://search.ieice.org/.
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Isaac, Leslie Thomas. "Puffer circuit breaker diagnostics using novel optical fibre sensors." Thesis, University of Liverpool, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263762.
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ZARKA, NIZAR. "Conception d'un circuit integre de detection optimale de contours." Paris 6, 1992. http://www.theses.fr/1992PA066373.
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L'extraction de contours joue un role important dans tout systeme de vision par ordinateur. Les techniques de detection de contours sont nombreuses. La plupart utilisent des operateurs locaux de derivation du premier ordre ou du second ordre. Ces operateurs sont sensibles aux bruits, et souvent ne donnent pas de bons resultats sur une image reelle. Depuis quelques annees, on assiste a de nouveaux algorithmes en extraction de contours qui procedent par optimisation de criteres prenant en compte un modele predefini du contour a detecter. Ces algorithmes peuvent etre implementes par des filtres recursifs qui ont l'avantage de necessiter un nombre faible et constant d'operateurs. Cette these donne le detail de la conception et de la realisation d'un circuit integre implementant des algorithmes de detection optimale de contours. Le circuit est cascadable pour paralleliser le traitement. La surface du circuit est de 66. 4 mm#2 en technologie cmos 1. 5 um de compass avec 181000 transistors et 68 broches. Le circuit presente l'avantage d'avoir une architecture systolique implementant des filtres recursifs du second ordre. La vitesse du traitement (calcul du gradient horizontal ou vertical), avec deux circuits travaillant en parallele, est de 38 images par seconde pour des images de 256256 pixels
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Al-Saqer, A. Y. "The optimal design of GIC-derived bandpass active filters." Thesis, University of Essex, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356043.
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Bhandare, Suhas. "Application of lithium niobate based integrated optical circuits to optical communication." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=971581703.
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BARBIO, VALTER SILVA. "IMPLEMENTATION OF ALL OPTICAL CLOCK VECOVERY CIRCUITS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1997. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=8878@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR<br>A tendência de um rápido aumento nas taxas de transmissão
utilizadas em sistemas de comunicações ópticas, impõe que
sejam repensadas as tecnologias e princípios de fabricação
dos diversos elementos de um sistema de transmissão ou de
recepção. Em breve, sistemas operando em taxas superiores
a 100Gbits/s serão uma realidade. Este trabalho propõe-se
a analisar o problema da extração de relógio em receptores
ópticos de alta capacidade. O processo, atualmente
empregado, é completamente elétrico sendo dificultado
devido a sensibilidade dos componentes eletrônicos à
freqüência de operação. Apresenta-se neste trabalho um
método de recuperação de relógio por processo óptico,
utilizando-se como elemento fundamental um laser DFB multi-
seção. Inicialmente será realizado um estudo teórico do
fenômeno de auto-pulsação, pré-requisito para a extração
de relógio por processo óptico. Em seguida serão
apresentados e discutidos uma série de experimentos que
demonstram a recuperação de relógio por processo óptico. A
partir destas informações e das condições adequadas para a
obtenção do fenômeno, implementa-se um set-up experimental
utilizando-se um laser InGaAsP/InP DFB dupla-seção, a
partir do qual obtém-se recuperação de relógio por
processo óptico em 1,24Gbits/s e 2,48Gbits/s nos formatos
RZ e NRZ.<br>Today bit-rates increase quickly in optical communications
sustems. New technologies and fabrication process
discovers are fundamental to the development of several
devices in the transmission and reception systems. Soon,
optical communication systems working in 100Gbits/s will
be a reality. This work intends to solve the problem of
clock recovery in high capacitu optical receivers. The
process employed nawadays is completely electrical. As it
is known, electronics devices are limited in frequency,
and won´t operate propely in such high bit-rates. In this
work a optical clock recovery method is shown, using a
multi-section laser, as main element. The first step will
be the description of a theoretical study of the self-
pulsation phenomenon, allowing the understanding of the
mechanism of optical clock recovery. Afterwards a series
of experiments that show optical clock recovery are
preented and discussed. A experimental set-up is
implemented, utilizing a InGsAsP/InP doublesection DFB
laser, and optical clock recovery is obtained from
1,24Gbits/s and 2,48Gbits/s bit streams, in RZ and NRZ
formats.
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Williams, Ryan Daniel. "Photonic integrated circuits for optical logic applications." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42025.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2007.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Includes bibliographical references.<br>The optical logic unit cell is the photonic analog to transistor-transistor logic in electronic devices. Active devices such as InP-based semiconductor optical amplifiers (SOA) emitting at 1550 nm are vertically integrated with passive waveguides using the asymmetric twin waveguide technique and the SOAs are placed in a Mach-Zehnder interferometer (MZI) configuration. By sending in high-intensity pulses, the gain characteristics, phase-shifting, and refractive indices of the SOA can be altered, creating constructive or deconstructive interference at the MZI output. Boolean logic and wavelength conversion can be achieved using this technique, building blocks for optical switching and signal regeneration. The fabrication of these devices is complex and the fabrication of two generations of devices is described in this thesis, including optimization of the mask design, photolithography, etching, and backside processing techniques. Testing and characterization of the active and passive components is also reported, confirming gain and emission at 1550 nm for the SOAs, as well as verifying evanescent coupling between the active and passive waveguides. In addition to the vertical integration of photonic waveguides, Esaki tunnel junctions are investigated for vertical electronic integration. Quantum dot formation and growth via molecular beam epitaxy is investigated for emission at the technologically important wavelength of 1310 nm. The effect of indium incorporation on tunnel junctions is investigated. The tunnel junctions are used to epitaxially link multiple quantum dot active regions in series and lasers are designed, fabricated, and tested.<br>by Ryan Daniel Williams.<br>Ph.D.
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Kern, Alexandra M. 1979. "CMOS circuits for VCSEL-based optical IO." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40473.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.<br>Includes bibliographical references (p. 121-129).<br>Electrical IO is becoming limited by copper interconnect channel losses that depend on frequency and distance. Package-to-package optical interconnects see negligible frequency-dependent channel losses, but data rates are limited by the intrinsic optical dynamics and electrical parasitics of the optical devices. This thesis presents 90nm CMOS front-end circuits which apply techniques to operate optical components beyond the intrinsic data rates imposed by these bandwidth limits. The differential TIA is based on a proposed core amplifier which uses cross-coupled NMOS cascodes to increase gain and bandwidth. A symmetric feedback method provides constant gain from DC to 9GHz. The TIA operates at 12.5Gb/s with 260fF input capacitance and 18Gb/s with 90fF input capacitance for an input current of 200uA. The presented VCSEL driver operates a standard commercial GaAs VCSEL at 18Gb/s by using pre-emphasis to compensates for the large capacitance and intrinsic optical dynamics of the VCSEL. The driver derives timing information directly from the full-rate input data and generates pre-emphasis pulses with width resolution less than one bit period in a manner that is compatible with full-rate IO architectures.<br>(cont.) Because commercial GaAs VCSELs have limited bandwidth but short optical links often have excess link budget, multilevel signaling can be used to increase data rate by increasing the number of bits per symbol instead of increasing the symbol rate. A four-level (PAM-4) VCSEL driver architecture is therefore proposed to transmit at 20Gb/s with lower power consumption than the pre-emphasis driver due to reduced bandwidth requirements. Electrical and optical simulations of the transmitter circuits and behavioral simulations of a PAM-4 receiver and CDR are presented.<br>by Alexandra M. Kern.<br>Ph.D.
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Desai, Smit Haritkumar. "Integrated Photonics Circuits with Optical Crosstalk Reduction." Thesis, The University of Sydney, 2020. https://hdl.handle.net/2123/24981.
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Silicon integrated photonics has been at the forefront of research for complex applications such as LIDAR, switch arrays etc. Many of these applications require high number of channels for a single device which are classified as waveguide arrays. Highly dense arrays of waveguides present new challenges such as presence of optical crosstalk which introduce a trade-off between the performance and dimension of a device. In this thesis, I address the crosstalk limitations for dense optical phased arrays and optical splitters by applying crosstalk reduction methodologies such as superlattice or evanescent strip structures to achieve scalable and compact devices in Silicon on Insulator (SOI) platform. A combination of simulation methods such as finite-difference time domain (FDTD), finite element method (FEM) and Eigenmode expansion (EME) have been used to design the devices.
The thesis presents the negative impact of high optical crosstalk on the performance of optical splitters such as Multimode Interference coupler (MMI). A compact 6 µm x 10 µm MMI splitter with 6 output channels and superlattice crosstalk reduction method at the output has been demonstrated to achieve high uniformity of 0.83 dB and insertion loss of 0.3 dB. The scalable nature of the superlattice structure has also been shown.
Additionally, the thesis proposes a vertical grating coupler (VGC) for rib waveguides on 3C-Silicon Carbide (SiC) undercut domain. The design is optimized across a broad wavelength range of 1500-1600 nm using 2D-FDTD procedure. Largest coupling efficiency of 3.3 dB is achieved at 1560 nm with a broad bandwidth of 114 nm. This VGC spectrum has been used to quantify the impact of dry annealing on the dimensions of other SiC structures.
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Yurt, Abdulkadir. "Subsurface optical microscopy of semiconductor integrated circuits." Thesis, Boston University, 2014. https://hdl.handle.net/2144/12945.
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Thesis (Ph.D.)--Boston University<br>The semiconductor industry continues to scale integrated circuits (ICs) in accordance with Moore's Law, and is currently developing the processing infrastructure at the 14nm technology node and smaller. In the wake of such rapid progress, a number of challenges have arisen for the optical failure analysis methods to meet the requirements of the advancing process technology. Most notably, complex circuits with shrinking critical dimensions will demand higher resolution signal localization currently beyond the capability of the existing optical techniques. This dissertation aims to develop novel optical systems to address the challenges of non-destructive circuit diagnostics at the 14nm technology node and beyond.
Backside imaging through the silicon substrate has become an industry standard due to the dense multi-level metal wiring and the packaging requirements. The solid immersion lens is a plano-convex lens placed on the planar silicon substrate to enhance the subsurface focusing and collection of light in back-side imaging of ICs. The silicon and gallium-arsenide aplanatic solid immersion lenses (aSILs) were investigated in detail for the subsurface laser-scanning, voltage modulation, photon emission and dark-field IC imaging applications. Wave-front sensing and shaping techniques were developed to evaluate and mitigate optical aberrations originating from practical issues. Furthermore, the method of pupil function tailoring was explored for sub-diffraction spatial resolution. Super-resolving annular phase and amplitude pupil masks were developed and experimentally implemented. A record-breaking light confinement of 0.02 λ2 0(λ 0 refers to the free-space wavelength) was demonstrated using the vortex beams.
The beam invasiveness is a critical issue in the optical circuit probing as the localized heat due to the absorption of the focused beams may unwittingly interfere with the circuit operation in the course of a measurement. A dual-phase interferometry assisted circuit probing was developed to enhance the signal extraction sensitivity by as much as an order of magnitude. Thus, the power requirement of the probe beam is significantly reduced to avert the consequences of the beam invasiveness.
The optical systems and methods developed in this dissertation were successfully demonstrated using a number of modern ICs including devices of 14nm, 22nm, 28nm and 32nm technology nodes.
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Prabhu, Mihika. "Towards optimal capacity-achieving transceivers with photonic integrated circuits." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/115725.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2018.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 63-65).<br>Optical communication systems have many advantages over communication systems that operate in the radio-frequency range, including decreased size, weight, and power consumption and increased bandwidth. As a result, optical communication systems are emerging as the ideal choice in many resource-constrained links such as those deployed on spacecraft. This thesis presents progress on development of a programmable nanophotonic processor (PNP) for implementing a high-fidelity reconfigurable optical transceiver at the telecommunications wavelength. By encoding information in multiple spatial modes and detecting jointly over the modes using a unitary transform prior to detection, one can in principle attain Holevo-limited channel capacity in the low mean photon number regime. Since the PNP offers dynamic reprogrammability, one can also, in principle, correct for wavefront distortion in the channel. We present a setup, calibration protocols, and preliminary results towards a turbulence-resistant integrated BPSK transmitter and joint detection receiver channel that achieves superadditive channel capacity in the low mean photon number regime.<br>by Mihika Prabhu.<br>S.M.
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Ford, Helen Diana. "Optical fibre wavelength filters and multiplexers." Thesis, Cranfield University, 1994. http://dspace.lib.cranfield.ac.uk/handle/1826/10410.
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Polarisation-based
wavelength-division multi-/demulti-plexers (WDMs) and
filters have been designed, constructed and evaluated. These are compact devices made
from single-mode optical fibre possessing high linear birefringence.
Ihe WDMs accept two input wavelengths in a common state of polarisation, and
produce orthogonally polarised outputs which are spatially separated using a
polarisation-selective element. The maximum separation demonstrated is 1.5 nm, and
the minimum 0.04 nm, which is two orders of magnitude better than that achieved b
most other in-line WDMs.
A few metres of fibre only are required. Instantaneous cross-
talk values below -15 dB have been measured experimentally, and theoretical analysis
of the devices predicts that values below -28 dB should be attainable. Temperature
sensitivity currently limits long-term cross-talk, but also offers the possibility of tuning
the centre wavelength. Methods of reducing environmental sensitivity include judicious
choice
of fibre type and appropriate packaging of the WDMs. These techniques are
investigated and discussed. Incorporation of the WDMs in optical fibre sensing networks
is demonstrated, as is separation of frequency-shifted stimulated Brillouin scattered
light, generated in a fibre, from the pump frequency.
Filters are constructed
using concatenated sections of birefringent fibre,
positioned between two polarisers. Rotation of the polarisation azimuth between sections
is achieved
by twistíng portions of the fibre to induce circular birefringence. Thus
devices are made from a single strand of linearly birefringent fibre, less than one metre
in
length. Passband widths and separations are selected b changing the number of
twisted sections in the filter, and altering lengths and twist angles of sections. A
minimum passband width ofI0 nm has been demonstrated, at a passband separation
of60 nm. Environmental stability is suíciently good for the devices to be operated as
passive components.
49
Constable, Julie Ann. "Semiconductor optical amplifiers for analogue applications." Thesis, University of Bath, 1993. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358046.
Full text
50
Reed, G. T. "Optical strip waveguides in lithium niobate formed by helium ion implantation." Thesis, University of Surrey, 1987. http://epubs.surrey.ac.uk/843383/.
Full textAbstract:
The implantation of helium ions into lithium niobate produces a reduction in its refractive indices, due to radiation damage produced close to the end of the ion trajectories. This reduction can be utilised to form the boundaries of optical waveguides, which form the basis of any integrated optical circuit. Stripe waveguide fabrication using ion implantation has been demonstrated for the first time in this work. Firstly a buried damage layer was formed to define the depth of the waveguide, followed by additional implants around a gold mask to form the waveguide sidewalls. The gold mask was used to protect the guiding region during the latter implantation process. The waveguides were evaluated using the end-fire coupling technique to excite individual modes. Propagation loss and modal dimensions were determined experimentally for the fundamental mode of each guide, and it was shown that these properties are sensitive to both the ion energy of the wall implants, and the number of wall implants. Each of these two variables affects the propagation loss in the opposite sense to the other, and therefore the lowest propagation loss becomes dependant on the trade off between these two effects. The lowest loss of the waveguides presented in this thesis was found to be ~1 dB/cm, and it is expected that this figure may be further reduced by the optimisation suggested in the conclusions of this work. Additional results are presented which consider the electrooptic and photorefractive properties of ion implanted LiNbO3. Previous work of others suggested that the electrooptic effect would be considerably reduced in the implanted material, but the results were much more encouraging, showing a reduction of only ~20% in the r13 electrooptic coefficient. Furthermore, one of the most serious drawbacks of Ti:indiffused waveguides is the undesirable reduction of the output intensity due to the photorefractive effect, which has been shown not to affect the waveguides presented in this thesis.