Дисертації з теми "Optical information processing method"
Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: Optical information processing method.
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Optical information processing method".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
1
Братова, Дар'я Романівна. "Формування вейвлет вікон для фільтрації оптичної інформації". Master's thesis, КиЇв, 2019. https://ela.kpi.ua/handle/123456789/30424.
Повний текст джерелаАнотація:
Дисертаційна робота присвячена розробці методу для оптичної обробки інформації.
В інженерній практиці для дослідження різноманітних сигналів природного та штучного походження застосовуються різні класи перетворень – Фур’є, Лапласа тощо. З 80-х років минулого століття для частотночасового аналізу нестаціонарних сигналів переважно використовують вейвлетперетворення (ВП). Першими це зробили Морле та Гроссман, займаючись аналізом сейсмічних даних та когерентними квантовими станами відповідно. Математичні засади ВП було закладено Мейєром, який показав існування відповідних функцій (вейвлетів), що утворюють ортогональний базис в просторі L2(R), тобто в просторі дійсних функцій, квадрат котрих є інтегрованим. Добеші здійснила перехід від неперервного до дискретного ВП та розробила клас вейвлетів, що мають максимальну гладкість при фіксованій довжині свого носія. Наразі область застосування ВП – наближення функцій і сигналів, їх фільтрація та стиснення, пошук в сигналі певних особливостей тощо.
Магістерська дисертація складається з чотирьох розділів.
У першому розділі проаналізовано основні переваги і недоліки вейвлет та Фур’є перетворень та особливості їх використання. Також приведено приклади основних типів вейвлетів.
У другому розділі приведено загальну класифікацію вейвлетів та кожного з загальних окремо. Окрім цього розглянуто узагальнені характеристики різноманітних вейвлетів та методи їх розрахунку.
Третій розділ присвячено розробці метода формування вейвлет вікон для фільтраціі оптичної інформації. В третьому підрозділі продемонстровані результати аналізу експериментальних робіт попередників, які показують можливість створення синтезованих цифрових нелінійних голограм у якості вейвлет-фільтрів.
Четвертий розділ присвячено розробці стартап-проекту «Формування вейвлет вікон для фільтрації оптичної інформації» і аналізу перспектив входження розробки на ринок з маркетологічної точки зору.The dissertation is dedicated to developing a method for optical information processing. In engineering practice, different classes of transformation - Fourier, Laplace, etc. - are used to investigate the various signals of natural and artificial origin. Since the 1980s, wavelet transform (WF) has been predominantly used for frequency analysis of unsteady signals. Morle and Grossman were the first to do so, analyzing seismic data and coherent quantum states, respectively. The mathematical foundations of the WT were laid down by Meyer, who showed the existence of corresponding functions (wavelets) forming an orthogonal basis in the space L2 (R), that is, in the space of real functions whose square is integrated. Dobeshi made the transition from continuous to discrete WT and developed a class of wavelets that have maximum smoothness at a fixed length of their carrier. Currently, the scope of the WT is the approximation of functions and signals, their filtering and compression, searching for a signal of certain features, and more. The master's thesis consists of four sections. The first section analyzes the main advantages and disadvantages of wavelet and Fourier transforms and the features of their use. Examples of the main types of wavelets are also given. The second section provides a general classification of wavelets and each of them in general. In addition, the general characteristics of various wavelets and their calculation methods are considered. The third section is devoted to the development of a method of forming wavelet windows for filtering optical information. The third section presents the results of an analysis of the previous experimental works that show the possibility of creating synthesized digital nonlinear holograms as wavelet filters. The fourth section is devoted to the development of a startup project "Formation of wavelet windows for filtering optical information" and to analyze the prospects of entering the market from a marketing point of view.
2
ANDO, Hiroki, 大樹 安藤, Takeshi SAKAI, 猛. 酒井, Goro OBINATA та 五郎 大日方. "磁気記録評価装置用変位拡大位置決め制御機構の機構形状とコントローラの統合化設計". 日本機械学会, 2006. http://hdl.handle.net/2237/8963.
Повний текст джерела
3
Potter, Duncan J. "Phase-only optical information processing." Thesis, University of Edinburgh, 1993. http://hdl.handle.net/1842/845.
Повний текст джерелаАнотація:
Historically, much scientific work has been performed with two optical systems - the telescope and the microscope. Although Galileo was probably not the first to invent the refracting telescope, his rapid development of the instrument from 1609 results in his association as the father of the telescope today. Certainly he was the first human to view the giant moons of the planet Jupiter - Io, Ganymede, Callisto and Europa - and thus dare to venture our world was not the centre of the universe, and save our race from another thousand years of mysticism. A year later, in 1610, Galileo invented the microscope and this led to the new field of science called 'microscopy' to open up the previously unsuspected world of the ultra small. Tiny life forms no larger than a pinhead were revealed, and with instrumental improvements by later scientists the existance of bacteria proven. This discovery prompted the sterilisation of surgical equipment taken for granted today, saving countless millions of lives since then through freedom from bacterial infection. It is beyond doubt that the new world opened by the invention of the microscope inspired the scientists of that time to seek yet greater magnification and sharper images, to delve deeper into this tiny world. Yet technical improvement in the design of the microscope wase hampered by the lack of a proper theory of image formation. Not until the late nineteenth century, when ABBE and RAYLEIGH provided the foundations of the present day diffraction theory of imaging was the microcope properly understood. The work of this thesis has its roots in the developments of the early twentieth century microscopists. For many years they had observed tiny, transparent organisms and sought ways to improve the visibility of these creatures so that their nature might better be understood. The problem was solved by F.Zernike in 1935 (1, 425 for ref.) when he considered the way the organisms altered the phase of the illuminating light field. By the correct positioning of a thin phase-plate in the back focal plane of the microscope lens, Zernike demonstrated that optical thickness variations of the organism may be rendered visible as intensity variations. In this thesis , the light distribution in the back focal plane of such a lens that results from a transparent object is analysed in detail. From the expression derived by Zernike to explain the operating principle of his invention, we evaluate alternative formulations of the problem and proceed to a full analytical expression for the light field . Though mathematically awkward, it is shown the expression is not unworkable and several useful results are derived. In place of a microscope the study is based on imaging in a modern image processing bench, the physical principles involved being identical. Zernike introduced the idea of image modification through the use of a basic form of phase filter. The second half of this thesis develops this idea to show the use of much more intricate phase filters, which may be used to 'recognise' particular objects. Filter design is followed by experimental results on a special type of phase object, the programmeable Spatial Light Modulator.
4
Le, Jeannic Hanna. "Optical Hybrid Quantum Information processing." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066596/document.
Повний текст джерелаАнотація:
Approche hybride du traitement quantique de l'information La dualité onde-particule a conduit à deux façons d'encoder l'information quantique, les approches continues et discrètes. L'approche hybride a récemment émergé, et consiste à utiliser les concepts et boites à outils des deux approches, afin de venir à bout des limitations intrinsèques à chaque champ. Dans ce travail de thèse, nous allons dans une première partie utiliser des protocoles hybrides de façon à générer des états quantiques non-gaussiens de la lumière. A l'aide d'oscillateurs paramétriques optiques, et de détecteur de photons supraconducteurs, nous pouvons générer des photons uniques extrêmement purs très efficacement, ainsi que des états chats de Schrödinger, qui permettent d'encoder l'information en variables continues. Nous montrons également en quoi des opérations de variables continues peuvent aider cette génération. La méthode utilisée, basée sur la génération " d'états-noyaux " rend en outre ces états plus robustes à la décohérence. Dans une seconde partie, dans le contexte d'un réseau hétérogène, basé sur différents encodages, relier de façon quantique les deux mondes, nécessite l'existence d'intrication hybride de la lumière. Nous introduisons la notion d'intrication hybride, entre des états continus et discrets, et nous en montrons une première application qui est la génération à distance de bit quantique continu. Nous implémentons ainsi également une plateforme polyvalente permettant la génération d'états " micro-macro " intriquésIn quantum information science and technology, two traditionally-separated ways of encoding information coexist -the continuous and the discrete approaches, resulting from the wave-particle duality of light. The first one is based on quadrature components, while the second one involves single photons. The recent optical hybrid approach aims at using both discrete and continuous concepts and toolboxes to overcome the intrinsic limitations of each field. In this PhD work, first, we use hybrid protocols in order to realize the quantum state engineering of various non-Gaussian states of light. Based on optical parametric oscillators and highly-efficient superconducting-nanowire single-photon detectors, we demonstrate the realization of a high-brightness single-photon source and the quantum state engineering of large optical Schrödinger cat states, which can be used as a continuous-variable qubit. We show how continuous-variable operations such as squeezing can help in this generation. This method based on so-called core states also enables to generate cat states that are more robust to decoherence. Second, in the context of heterogeneous networks based on both encodings, bridging the two worlds by a quantum link requires hybrid entanglement of light. We introduce optical hybrid entanglement between qubits and qutrits of continuous and discrete types, and demonstrate as a first application the remote state preparation of continuous-variable qubits. Our experiment is also a versatile platform to study squeezing-induced micro-macro entanglement
5
Deng, Zhijie. "Novel optical devices for information processing." Texas A&M University, 2003. http://hdl.handle.net/1969.1/5863.
Повний текст джерелаАнотація:
Optics has the inherent advantages of parallelism and wide bandwidths in processing
information. However, the need to interface with electronics creates a bottleneck
that eliminates many of these advantages. The proposed research explores novel
optical devices and techniques to overcome some of these bottlenecks. To address
parallelism issues we take a specific example of a content-addressable memory that can
recognize images. Image recognition is an important task that in principle can be done
rapidly using the natural parallelism of optics. However in practice, when presented
with incomplete or erroneous information, image recognition often fails to give the
correct answer. To address this problem we examine a scheme based on free-space
interconnects implemented with diffractive optics. For bandwidth issues, we study
possible ways to eliminate the electronic conversion bottleneck by exploring all-optical
buffer memories and all-optical processing elements. For buffer memories we examine
the specific example of slow light delay lines. Although this is currently a popular
research topic, there are fundamental issues of the delay-time-bandwidth product
that must be solved before slow light delay lines can find practical applications. For
all-optical processing we examine the feasibility of constructing circuit elements that
operate directly at optical frequencies to perform simple processing tasks. Here we
concentrate on the simplest element, a sub-wavelength optical wire, along with a
grating coupler to interface with conventional optical elements such as lenses and
fibers. Even such a simple element as a wire has numerous potential applications. In conclusion, information processing by all-optical devices are demonstrated with
an associative memory using diffractive optics, an all-optical delay line using room
temperature slow light in photorefractive crystals, and a subwavelength optical circuit
by surface plasmon effects.
6
Clark, Alex S. "Quantum information processing in optical fibres." Thesis, University of Bristol, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.557975.
Повний текст джерелаАнотація:
The use of quantum particles provides unprecedented improvements for some computational tasks and has applications in provably secure communications. The choice of quantum particles for such processes is wide but single photons are a promising candidate due to their extremely low decoherence and light speed trans- mission. Current technology for the generation and processing of single photons is of exceptional experimental interest and forms the basis of my investigations in this thesis. I show the background theory of quantum information and communication, with a general analysis of qubits and optical quantum gates before looking more specifically at different sources of photonic qubits and the generation of photons. I then show recent improvements in photon generation using photonic crystal fi- bres (PCFs), most especially the use of cross-polar phase matching solutions that allow the generation of pure state photons via four wave mixing effects in a X(3} nonlinear medium. These therefore require no spectral filtering to be used for quantum information tasks, thereby improving collection rates and experimental integration times which are crucial when performing multi-photon experiments. The optimization of the parameters for such a source are achieved through the use of an analytical model, and the purity of the photons are tested through the use of quantum interference effects. I move on to show the construction and character- ization of a common two qubit gate, namely the controlled-NOT gate, in optical fibres using fibre based sources and describe it's usefulness and integrability into quantum communication networks. I then calculate bounds on the average gate fidelity of 0.83 < Fave < 0.91 and create a model to show the main sources of error in the controlled-NOT gate operation. If the PCF used in the above sources is pumped in opposite directions in a Sagnac loop configuration, pairs of photons are generated in a maximally entangled Bell state where the polarization of one photon is perfectly correlated with the other photon of the pair. If two such pairs are generated in separate sources and one photon from each pair mixed on a polarizing beam splitter, a fusion operation is performed that entangles those two photons creating a four photon cluster state where all photons are entangled. This cluster state is a universal resource for measurement based quantum computing. In this thesis I show the generation and characterisation of such a cluster state and describe its use to perform a universal set of gates through single qubit measurements. I finally describe future experiments using PCFs and cluster states.
7
Soutar, Colin. "Optical information processing using photorefractive BSO." Thesis, Abertay University, 1991. https://rke.abertay.ac.uk/en/studentTheses/a757b4d3-6c1e-4600-aed8-430e7078c6c5.
Повний текст джерелаАнотація:
Several optical information processing tasks are implemented using photorefractive BSO as a dynamic holographic medium. The physical basis for the mechanism which allows the implementation of these devices is studied. The properties of BSO which make it particularly attractive as a processing medium are highlighted, and experimental results are presented to demonstrate its practical limitations. An extensive study is presented of the influence of optical bias on the grating formation characteristics. This leads to a documentation of the optimum conditions for transient enhancement of a beam diffracted from such a grating. This transient enhancement can be controlled to provide ideal characteristics for the implementation of transient devices such as a novelty filter. A novelty filter utilising this transient enhancement is subsequently demonstrated. It exhibits good temporal discrimination through the choice of suitable external optical conditions, and the use of digital thresholding. The overall device operates at T.V. frame rates. Results are also presented of various optical correlators using BSO. These include the optical intensity correlator. The unique properties of the intensity correlator are stressed by practical demonstration. Specifically, the relative intolerance of the intensity correlator (compared with coherent correlators) to the position of the various components is demonstrated. Also, the spatially incoherent readout light allows the use of a low-optical quality liquid crystal television (LCTV) as a low-cost spatial light modulator. Output results are then presented from the correlator using the LCTV as a dynamic readout device. This provides an updateable hologram as the reference of the correlator which is interrogated at frame rates by the LCTV. Finally, the temporal discrimination of the novelty filter is combined with the character recognition ability of the intensity correlator. This produces an optical processor which will recognise a particular object but will only register it at the output stage when it is moving.
8
Tian, Kehan. "Three dimensional (3D) optical information processing." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/35627.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.Includes bibliographical references (p. 141-151).
Light exhibits dramatically different properties when it propagates in or interacts with 3D structured media. Comparing to 2D optical elements where the light interacts with a sequence of surfaces separated by free space, 3D optical elements provides more degrees of freedom to perform imaging and optical information processing functions. With sufficient dielectric contrast, a periodically structured medium may be capable of forbidding propagation of light in certain frequency range, called band gap; the medium is then called a photonic crystal. Various "defects", i.e. deviations from perfect periodicity, in photonic crystals are designed and widely used as waveguides and microcavities in integrated optical circuits without appreciable loss. However, many of the proposed waveguide structures suffer from large group velocity dispersion (GVD) and exhibit relatively small guiding bandwidth because of the distributed Bragg reflection (DBR) along the guiding direction. As optical communications and optical computing progress, more challenging demands have also been proposed, such as tunable guiding bandwidth, dramatically slowing down group velocity and active control of group velocity. We propose and analyze shear discontinuities as a new type of defect in photonic crystals.
(cont.) We demonstrate that this defect can support guided modes with very low GVD and maximum guiding bandwidth, provided that the shear shift equals half the lattice constant. A mode gap emerges when the shear shift is different than half the lattice constant, and the mode gap can be tuned by changing the amount of the shear shift. This property can be used to design photonic crystal waveguides with tunable guiding bandwidth and group velocity, and induce bound states. The necessary condition for the existence of guiding modes is discussed. By changing the shape of circular rods at the shear interface, we further optimize our sheared photonic crystals to achieve minimum GVD. Based on a coupled resonator optical waveguide (CROW) with a mechanically adjustable shear discontinuity, we also design a tunable slow light device to realize active control of the group velocity of light. Tuning ranges from arbitrarily small group velocity to approximately the value of group velocity in the bulk material with the same average refractive index. The properties of eigenstates of tunable CROWs: symmetry and field distribution, and the dependence of the group velocity on the shear shift are also investigated.
(cont.) Using the finite-difference time-domain (FDTD) simulation, we demonstrate the process of tuning group velocity of light in CROWs by only changing the shear shift. A weakly modulated 3D medium diffracts light in the Bragg regime (in contrast to Raman-Nath regime for 2D optical elements), called volume hologram. Because of Bragg selectivity, volume holograms have been widely used in data storage and 3D imaging. In data storage, the limited diffraction efficiency will affect the signal-noise-ratio (SNR), thus the memory capacity of volume holograms. Resonant holography can enhance the diffraction efficiency from a volume hologram by enclosing it in a Fabry-Perot cavity with the light multiple passes through the volume hologram. We analyze crosstalk in resonant holographic memories and derive the conditions where resonance improves storage quality. We also carry out the analysis for both plane wave and apodized Gaussian reference beams. By utilizing Hermite Gaussian references (higher order modes of Gaussian beams), a new holographic multiplexing method is proposed - mode multiplexing.
(cont.) We derive and analyze the diffraction pattern from mode multiplexing with Hermite Gaussian references, and predict its capability to eliminate the inter-page crosstalk due to the independence of Hermite Gaussian's orthogonality on the direction of signal beam as well as decrease intra-page crosstalk to lower level through apodization. When using volume holograms for imaging, the third dimension of volume holograms provided more degrees of freedom to shape the optical response corresponding to more demanding requirements than traditional optical systems. Based on Bragg diffraction, we propose a new technique - 3D measurement of deformation using volume holography. We derive the response of a volume grating to arbitrary deformations, using a perturbative approach. This result will be interesting for two applications: (a) when a deformation is undesirable and one seeks to minimize the diffracted field's sensitivity to it and (b) when the deformation itself is the quantity of interest, and the diffracted field is used as a probe into the deformed volume where the hologram was originally recorded.
(cont.) We show that our result is consistent with previous derivations motivated by the phenomenon of shrinkage in photopolymer holographic materials. We also present the analysis of the grating's response to deformation due to a point indenter and present experimental results consistent with theory.
by Kehan Tian.
Ph.D.
9
Davison, Alan Stephen. "All-optical signal processing devices." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316729.
Повний текст джерела
10
Arain, Muzamil Arshad. "INTERFEROMETRY-BASED FREE SPACE COMMUNICATION AND INFORMATION PROCESSING." Doctoral diss., University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3304.
Повний текст джерелаАнотація:
This dissertation studies, analyzes, and experimentally demonstrates the innovative use of interference phenomenon in the field of opto-electronic information processing and optical communications. A number of optical systems using interferometric techniques both in the optical and the electronic domains has been demonstrated in the filed of signal transmission and processing, optical metrology, defense, and physical sensors. Specifically it has been shown that the interference of waves in the form of holography can be exploited to realize a novel optical scanner called Code Multiplexed Optical Scanner (C-MOS). The C-MOS features large aperture, wide scan angles, 3-D beam control, no moving parts, and high beam scanning resolution. A C-MOS based free space optical transceiver for bi-directional communication has also been experimentally demonstrated. For high speed, large bandwidth, and high frequency operation, an optically implemented reconfigurable RF transversal filter design is presented that implements wide range of filtering algorithms. A number of techniques using heterodyne interferometry via acousto-optic device for optical path length measurements have been described. Finally, a whole new class of interferometric sensors for optical metrology and sensing applications is presented. A non-traditional interferometric output signal processing scheme has been developed. Applications include, for example, temperature sensors for harsh environments for a wide temperature range from room temperature to 1000 degree C.Ph.D.
Optics and Photonics
Optics
11
Nicholas, Julian Jesuratnam. "Information processing in #parallel' visual pathways." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386633.
Повний текст джерела
12
Alic, Nikola. "Information processing for improved performance of optical networks." Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2006. http://wwwlib.umi.com/cr/ucsd/fullcit?p3205498.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--University of California, San Diego, 2006.Title from first page of PDF file (viewed April 4, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 151-158).
13
Baker, Luke James. "Superconducting nanowire devices for optical quantum information processing." Thesis, University of Glasgow, 2018. http://theses.gla.ac.uk/8440/.
Повний текст джерелаАнотація:
Near infrared photons are a promising choice for quantum information processing; their low transmission loss is necessary for applications such as long distance Quantum Key Distribution (QKD) in optical fibre and integrated quantum optics. An ideal proof-of-concept test of such applications would be to create, manipulate and detect single photons on a monolithic chip. Superconducting nanowire single photon detectors promise high system detection efficiencies, low dark count and low jitter under near-infrared photon illumination. Superconducting nanowire devices using NbTiN films show improved coupling efficiencies with the aid of oxidized silicon cavities. NbTiN devices were characterised in a fibre-coupled package, achieving high SDE (43%) coherent key generation rates over 200km in a T12 QKD protocol simulation. Hairpin superconducting nanowires offer excellent integration with silicon waveguide optics and can achieve near unity absorption efficiencies. Hairpin devices fabricated from MoSi films were characterised using a custom pulse tube He-3 cryostat engineered for low vibration operation at 350mK and capable of near-infrared optical maps of superconducting nanowires. The devices exhibited high critical currents 40uA), low jitter (51ps) and a dark count rate <10cps. Tests of perpendicular coupling efficiencies yield low system detection efficiencies due to high coupling losses. Using an alternative coupling method via grating couplers or cleave mounting, it is expected a much higher system detection efficiency can be achieved.
14
Jacobo, Adrian. "Spatial structures and Information Processing in Nonlinear Optical Cavities." Doctoral thesis, Universitat de les Illes Balears, 2009. http://hdl.handle.net/10803/9436.
Повний текст джерела
15
Nazir, Ahsan. "Optical schemes for quantum information processing in semiconductor nanostructures." Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409819.
Повний текст джерела
16
Kalasuwan, Pruet. "Optical quantum information processing in higher dimensional Hilbert space." Thesis, University of Bristol, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.573150.
Повний текст джерелаАнотація:
In this thesis, we present and demonstrate several schemes for linear optical quantum information processing. Our schemes access. a higher-dimensional Hilbert space in order to simplify some particular quantum information tasks. We show how to expand a polarization-encoded cluster state by accessing and manipulating its spatial degree of freedom. This is realized using a polarization- path controlled-phase gate. We invented a method of adding control to quantum operations by accessing a higher dimensional Hilbert space, significantly reducing the complexity of some quantum circuits. A key advantage of this scheme is that control can be added even to unknown operations. This feature is required in some quantum information applications, such as the phase estimation algorithm, in which the phase is unknown. Using this method, we experimentally demonstrate a number of two-qubit photonic quantum gates, including a CNOT gate, CU gates, and entanglement filters and splitters. Using the same technique, we implemented the complete quantum phase estimation algorithm for a single qubit unitary, and we used the same circuit to realize an eigenstate generator. Our results point the way to efficient quantum simulations and quantum metrology in the near-term, and to large-scale quantum computations in the longer-term.
17
Lowans, Brian Sinclair. "Applications of spatial light modulators in optical information processing." Thesis, Queen's University Belfast, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282231.
Повний текст джерела
18
Miller, Paul Cecil. "Developments in optical information processing using spatial light modulators." Thesis, Queen's University Belfast, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336128.
Повний текст джерела
19
Lord, Angus. "Localised states in nonlinear optical systems." Thesis, University of Strathclyde, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248315.
Повний текст джерела
20
Klein, Alexander. "Special purpose quantum information processing with atoms in optical lattices." Thesis, University of Oxford, 2007. http://ora.ox.ac.uk/objects/uuid:bc67ec3e-3cc7-4d13-ae11-b436b2ca897b.
Повний текст джерелаАнотація:
Atoms in optical lattices are promising candidates to implement quantum information processing. Their behaviour is well understood on a microscopic level, they exhibit excellent coherence properties, and they can be easily manipulated using external fields. In very deep optical lattices, each atom is restricted to a single lattice site and can be used as a qubit. If the lattice is shallow enough such that the atoms can move, their properties can be used to simulate certain condensed matter phenomena such as superconductivity. In this thesis, we show how technical problems of optical lattices such as restricted decoherence times, or fundamental shortcomings such as the lack of phonons or strong spin interactions, can be overcome by using current or near-future experimental techniques. We introduce a scheme that makes it possible to simulate model Hamiltonians known from high-temperature superconductivity. For this purpose, previous simulation schemes to realise the spin interaction terms are extended. We especially overcome the condition of a filling factor of exactly one, which otherwise would restrict the phase of the simulated system to a Mott-insulator. This scheme makes a large range of parameters accessible, which is difficult to cover with a condensed matter setup. We also investigate the properties of optical lattices submerged into a Bose-Einstein condensate (BEC). A weak-coupling expansion in the BEC-impurity interaction strength is used to derive a model that describes the lattice atoms in terms of polarons, i.e.~atoms dressed by Bogoliubov phonons. This is analogous to the description of electrons in solids, and we observe similar effects such as a crossover from coherent to incoherent transport for increasing temperatures. Moreover, the condensate mediates an attractive off-site interaction, which leads to macroscopic clusters at experimentally realistic parameters. Since the atoms in the lattice can also be used as a quantum register with the BEC mediating a two-qubit gate, we derive a quantum master equation to examine the coherence properties of the atomic qubits. We show that the system exhibits sub- and superdecoherence and that a fast implementation of the two-qubit gate competes with dephasing. Finally, we show how to realise the encoding of qubits in a decoherence-free subspace (DFS) using optical lattices. We develop methods for implementing robust gate operations on qubits encoded in a DFS exploiting collisional interactions between the atoms. We also give a detailed analysis of the performance and stability of the gate operations and show that a robust implementation of quantum repeaters can be achieved using our setup. We compare the robust repeater scheme to one that makes use of conventional qubits only, and show the conditions under which one outperforms the other.
21
Paredes-Barato, David. "Towards optical quantum information processing using Rydberg dark-state polaritons." Thesis, Durham University, 2014. http://etheses.dur.ac.uk/10889/.
Повний текст джерелаАнотація:
This thesis proposes a novel method to implement universal quantum gates for photonic qubits using the strong dipole-dipole interactions present in a cold gas of Rydberg atoms and the control offered by microwave fields. By means of electromagnetically induced transparency (EIT) we store the information encoded in photonic qubits as Rydberg excitations, and then couple these to neighbouring states using microwaves. Microwaves alter the range of the dipole-dipole interactions between the excitations, and a suitable geometrical arrangement of the excitations in the cloud leads to a controlled π phase shift in the system's wavefunction, the basis of the universal gates proposed. After processing, the excitations in the medium are later retrieved as photons. A theoretical description of the implementation of a 2-qubit universal gate is presented and a numerical analysis shows the feasibility of its implementation in a cold cloud of Rubidium atoms. A scheme is also proposed to construct more general gates with applications in quantum information processing. These schemes have been made possible by the analysis of recent experiments performed in the group. This analysis is repeated here, along with the characterization of parts of the detection system required to obtain them.
22
Chaudhry, Mohammed Sabih. "Microwave I.F signal processing strategies for coherent optical communications." Thesis, Bangor University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357247.
Повний текст джерела
23
Ott, Melanie N. "Incoherent projection Moire contour sensing with coherent processing for large structures." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-08182009-040501/.
Повний текст джерела
24
Leibrandt, David R. "Integrated chips and optical cavities for trapped ion quantum information processing." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/53229.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2009.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 145-158).
Quantum information processing is a new and exciting field which uses quantum mechanical systems to perform information processing. At the heart of the excitement are quantum computation - which promises efficient algorithms for simulating physical systems, factoring, and searching unsorted databases - and quantum communication - which provides a provably secure communications protocol. Trapped ions show much promise for achieving large-scale quantum information processing. Experiments thus far have demonstrated small algorithms and entanglement of two remote ions. Current work focuses on scaling to large numbers of ions for quantum computation and interconversion between trapped ions and photons for quantum communication. This thesis addresses some of the challenges facing scaling and interconversion for trapped ion quantum information processing. The first part of the thesis describes the development of scalable, multiplexed ion trap chips for quantum computation. The ion trap chips are based on a new ion trap geometry, called the surface-electrode trap, in which all of the electrodes reside in a single plane. Three generations of surface-electrode traps are designed, fabricated, and tested - culminating with the demonstration of an ion trap chip microfabricated using standard silicon VLSI materials and processes for scalability to small trap size and large arrays of interconnected ion traps. The second part of the thesis presents an experiment that demonstrates cavity cooling, a method of laser cooling the motional state of trapped ions without decohering the internal qubit state.
(cont.) Cavity cooling is demonstrated for the first time with trapped ions, and for the first time in the parameter regime where cooling to the motional ground state is possible. The measured cavity cooling dynamics are found to agree with a rate equation model without any free parameters. The third and final part of the thesis presents a theoretical proposal for interconversion between single trapped ion qubits and single photon qubits for quantum communication. The idea is to map the state of the single ion qubit to a superradiant collective state of several ions, which then couples strongly with single photons in an optical cavity.
by David R. Leibrandt.
Ph.D.
25
Qureshi, Faisal. "The nonlinear optical properties of conjugated molecular materials." Thesis, University of Sheffield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264642.
Повний текст джерела
26
Ranshaw, M. J. "Phase-modulating spatial light modulators." Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/14252.
Повний текст джерела
27
Shi, H. (Henglin). "A GQM-based open research data technology evalution method in open research context." Master's thesis, University of Oulu, 2016. http://urn.fi/URN:NBN:fi:oulu-201605221853.
Повний текст джерелаАнотація:
Open Research Data is gaining popularity nowadays, and various research units and individuals are interested to join this trend. However, due to variety of Open Research Data technologies, they have found it is difficult to select proper ones for their specific requirements. Thus, a method for evaluating of Open Research Data related technologies is developed in this study for researchers to select proper ones.
Firstly, the theoretical knowledge of research data sharing and reusing barriers is resulted from a structured literature review. As a result, from the 19 primary studies, 96 instances of existing barriers are identified and classified to seven categories, where four of them are research data sharing barriers and rest of them are reusing barriers. This knowledge is regarded as an important resource for understanding researchers’ requirements on Open Research Data technologies, and utilized to develop the technology evaluation method.
Additionally, the Open Research Data Technology Evaluation Method (ORDTEM) is developed basing on the Goal/Question/Metric (GQM) approach and resulted research data sharing and reusing barriers. To develop this method, the GQM approach is adopted as the main skeleton to transform these barriers to measurable criterion. Consequently, the ORDTEM, which is consisting of six GQM evaluation questions and 14 metrics, is developed for researchers to evaluate Open Research Data technologies.
Furthermore, to validate the GQM-based ORDTEM, a focus groups study is conducted in a workshop. In the workshop, nine researchers who has the need to participate Open Research Data related activities are recruited to form a focus group to discuss the resulted ORDTEM. And by analysing the content of the discussion, 16 critical opinions are addressed which resulted eight improvements including one refinement on an existing metric and seven new metrics to ORDTEM.
Lastly, a testing process of applying ORDTEM to evaluate four selected Open Research Data technologies is implemented also for validating whether it can be used in solving real-world evaluation tasks. And more than the validation, this experiment also results the materials about usage of ORDTEM, which is useful for future adopters.
However, more than developing the solution to eliminate the difficulty of selecting technologies for participating Open Research Data movements, this study also provides two additional contributions. For one thing, resulted research data sharing and reusing barriers also direct the future effort to prompt Open Research Data and Open Science. Moreover, the experience of utilizing the GQM approach to transform existing requirements to evaluation criterion is possible to be studied for developing other requirement-specific evaluation.
28
KAIMAL, VINOD GOPALKRISHNA. "A NEURAL METHOD OF COMPUTING OPTICAL FLOW BASED ON GEOMETRIC CONSTRAINTS." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1037632137.
Повний текст джерела
29
Humphreys, Peter Conway. "Experimental and theoretical techniques for quantum-enhanced metrology and optical quantum information processing." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:57e942ac-f6f1-43fe-ac77-ef85b7db85ca.
Повний текст джерелаАнотація:
Over the last few decades, quantised excitations of the electromagnetic field have proven to be an ideal system with which to investigate and harness quantum optical phenomena. The techniques developed have enabled fundamental tests of quantum mechanics as well as practical applications in quantum metrology and quantum information processing. Advancing to larger-scale entangled quantum systems will open up new regimes of quantum many-body physics, allowing us to probe the limits of quantum mechanics and enabling truly quantum-enhanced technologies. However, moving towards this goal will require further experimental and theoretical innovations. The work described in this thesis focuses on several different aspects of optical quantum information, but are ultimately all linked by this long-term aim. The first part of this thesis describes a novel method for strain-based active control of quantum optical circuits and a new method for the characterisation of high efficiency detectors. Building on this, I discuss in detail two different fields of quantum optics that stand to benefit from these techniques. I initially consider quantum-enhanced metrology, including work aimed towards demonstrating a truly better-than-classical phase measurement, and a theoretical exploration of multiple-phase estimation. Finally, I focus on linear-optical quantum information processing, exploring in detail the use of time-frequency encodings for quantum computing.
30
Kauhanen, T. R. (Tiia-Riikka). "Designing a method for measuring the difficulty in kitchen tasks with people suffering from dementia." Master's thesis, University of Oulu, 2015. http://urn.fi/URN:NBN:fi:oulu-201510292098.
Повний текст джерелаАнотація:
The number of people with dementia is growing as people live longer. The old-age dependency ratio is predicted to increase in Europe. Institualization of the seniors is an undesirable solution in respect of quality of life and economics. Cooking is an important part of independent living, and it could be supported with assistive technologies, such as prompting systems to increase the independence of seniors. Because of the varying and individualistic effects of dementia, different seniors require tailored assistance from the prompting system.
This design science research is part of ASTS project that designs new technologies for assisting seniors with dementia to remain independent. The aim of this thesis is to develop a method that can be used to measure the level of difficulty in cooking tasks for individual seniors when the aim is to find an optimal task-person combination.
This aim is accomplished by researching existing research to develop a test procedure. The test can be used to model the actions of the focus group, the difficulty of the task and the level of assistance required. The results are then used to create an individual action model that can be used to compare differences between individuals and to optimize a prompting system to assists seniors in cooking activities for the client.
According the requirements of the client, a simple oven porridge recipe was chosen for the tests. Using existing theories the recipe was redesigned into workflow process model with very specific steps on how to cook porridge. The process model was validated with two pilot tests where a prompting system was imitated by verbal prompts.
The actual tests were conducted with two researchers and three participants in a kitchen that was available for the participants. The tests were analyzed by adapting existing studies and methods for evaluating cognitive impairment in daily tasks. The resulting action models illustrate the workflow of senior with dementia and how to measure difficulty in kitchen tasks. The method design process was evaluated with the client, and the results of the study were compared to existing research.
The designed method for measuring difficulty in kitchen tasks has five steps. The first step is to redesign a recipe into workflow process model that is built out of take, give, move and alter actions. The second step is to design a test layout for the chosen task. Alternatively, the process model and layout proposed in this study can be used.
The third step is to conduct the test by giving the participant different level prompts. In the fourth step, errors that occurred are identified. The fifth step is to create the action models by calculating probabilities of each error occurring.
31
Higashino, Satoru. "Study on signal processing and coding techniques for high density optical information storage channels." 京都大学 (Kyoto University), 2006. http://hdl.handle.net/2433/135949.
Повний текст джерела
32
Lau, Kai Kwong Gervas. "A new statistical stroke recovery method and measurement for signature verification." HKBU Institutional Repository, 2005. http://repository.hkbu.edu.hk/etd_ra/661.
Повний текст джерела
33
Yu, Donggang, and dyu@venus it swin edu au. "Processing and recognition of document and GIS images." Swinburne University of Technology, 2005. http://adt.lib.swin.edu.au./public/adt-VSWT20050812.095914.
Повний текст джерелаАнотація:
In intelligent document processing system and geographical information systems (GIS), the image processing and recognition play an important role. This thesis deals with various problems in processing images in documents and GIS: image smoothing, filling, linearization and extraction of contour features, extraction of structural points, separation and recognition of spurious segments in handwritten digits, reconstruction and recognition of broken digits, and separation and recognition of colour document and GIS images. These approaches are also called Optical Character Recognition (OCR).
A new smoothing technique is developed to smooth follow contours of image. With the new smoothing algorithms, spurious pixels (points) of contours are removed based on smooth patterns, and smooth followed contours are found. Also, skeletons of image can be smoothed between neighboring �end� and �junction� points. Smooth following makes linearization of smoothed contours possible based on Freeman codes.
A new filling algorithm of contours, project filling, is described based on two kinds of structural patterns. By this method, any complicated contours of images can be filled correctly.
Different from other linearization methods, linearization and feature extraction of smoothed contours are based on difference chain codes. Curvature and bend angles of linearized are found. The convexity and concavity of linearized are described. In this way, a series of description features of contours is formed.
Structural points are new and useful features to describe morphological structures between neighboring linearized lines. Extraction of structural points is based on structural patterns which are determined by element chain codes. Also, extension Freeman codes are used in this thesis. Structural points make description and recognition of contours possible.
In order to recognize handwritten digits in document processing systems, separation of spurious segments, reconstruction of broken digits and recognition of handwritten digits are investigated. Experiments with large number of testing data set show satisfactory results for these algorithms.
Separation and recognition of colour document and GIS images are discussed. Object images of document and GIS images are extracted based on the description of shape structures, prior knowledge and color information, which are associated with each other. Color images can be described by a limited number of colors in color document and GIS images. Therefore, separation of color image is done by color reduction method, and recognition of object images is based on structure patterns, prior knowledge and colour information. It can be seen that specific information should be considered in many practical problems to achieve better processing results.
34
Khan, Mughees Mahmood. "Fabrication and testing of nano-optical structures for advanced photonics and quantum information processing applications." [College Station, Tex. : Texas A&M University, 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1165.
Повний текст джерела
35
Кожухар, Павло Вікторович. "Кількісний контроль магнітних параметрів документів магнітооптичною телевізійною системою". Thesis, НТУУ «КПІ», 2016. https://ela.kpi.ua/handle/123456789/17695.
Повний текст джерелаАнотація:
В дисертаційній роботі розроблено магнітооптичну телевізійну систему, яка на відміну від відомих, дозволяє окрім якісного виконувати кількісний магнітний контроль документів. Розроблено узагальнений метод кількісного контролю магнітних параметрів документів, що дозволяє їх rласифікацію зі зниженим впливом шумів магнітооптичного перетворення, чутливістю до зміни параметрів намагнічування та неоднорідностей щільності друку. Удосконалено метод магнітооптичного топографування, що дозволяє отримувати сигнал двовимірного розподілу розсіяного магнітного поля елементів документів у матричній цифровій формі. Запропоновано методику оцінки чутливості і роздільної здатності телевізійної системи магнітооптичного контролю. Виконано комплексне експериментальне дослідження теоретичних напрацювань. Розроблені методи дозволяють підвищити вірогідність магнітного контролю (виявлення фальсифікації) документів, як виготовлених промислових методом (банкноти та захищені бланки) так і загально доступним (друк побутовою оргтехнікою) за рахунок виконання кількісного контролю їх магнітних параметрів. При цьому телевізійні системи, що реалізують запропоновані методи зберігають можливість якісного топологічного та трасологічного дослідження, тобто на відміну від відомих забезпечують комплексний магнітний контроль документів.The magnetic control of documents (including banknotes and protected blanks) is used at its production, banking and forensic research. Present devices divide into two groups. First ones are using a stock of huge induction or Hall sensors and performing only quantitative magnetic control with low resolution. Second ones are using magneto-optic sensors, which allows doing qualitative magnetic control with high resolution but could not perform quantitative control due to low dynamic range. The dissertation covers developing of TV system intended for quantitative control of magnetic parameters of documents using magneto-optic sensor, which have not implemented. It allows increasing the accuracy of magnetic control of documents due to providing integrated (quantitative and qualitative) magnetic control with high resolution and using only one sensor. Developed generalized method of quantitative control of magnetic parameters of documents allows its classification with decreased effect of magneto-optic noise and sensitivity to changing of magnetization and print density. This method involves getting a two-dimensional distribution of the signal of scattered magnetic field of documents in matrix digital form perhaps improved method of magneto-optical topography with auxiliary magnetic field source and coprocessing of magneto-optic images by TV system. Thus, documents spatial distribution of magnetic flux density is obtained in suitable for digital automated signal processing form. The next steps are calculating histograms of magnetic field of reference and controlled documents; approximation and normalization of this histograms; pairwise comparison of normalized histograms by proposed qualitative index of dissimilarity and making check solution about a membership of controlled document at reference group. All these steps are performed automatically by TV system so the method allows decreasing expenditure of time during magnetic control of documents. In addition there is suggested the procedure of evaluating the sensitivity and resolution of the TV system for the magneto-optic check. It consist in SNR evaluation of magneto-optic image of test document sample with known signal and no-signal areas. A comprehensive experimental study of the theoretical developments is passed. Developed magneto-optical TV system allows detecting reprinting of document by another printer with accuracy 50 – 100% (for examined printing samples) at the expense of proposed qualitative control. There is proved for examined banknote samples a capability to detect a falsification of banknotes magnetic protection by developed system even if present (qualitative-only) magneto-optic detectors cannot detect falsification due to same topology of magnetic print. The sensitivity and resolution of developed TV system allows detection of magnetic paint strokes 21 μm width and resolution of strokes with width and spaced by 42 μm with SNR not less than 6 dB. Thus, developed methods allow to increase the accuracy of magnetic control (detection of falsification) of documents through the implementation of the quantitative control of their magnetic parameters, both for documents manufactured by industry (banknotes and protected forms) and made in publicly available way (print by office equipment). Herewith television systems implementing the method, retain the ability to qualitative documents research like topological and trasological, i. e. in contrast to known provide an integrated magnetic control of documents. That’s why scientific and practical results are implemented magneto-optic TV systems Regula 4197 and Regula 7701M, modern methodology of forensic research of magnetic print and digital help-desk system “Currensy”, which contains samples of magnetic parameters of world banknotes made by indicated above TV systems.
В диссертационной работе разработана магнитооптическая телевизионная система, которая в отличии от известных, позволяет помимо качественного выполнять количественный магнитный контроль документов. Разработан обобщенный метод количественного контроля магнитных параметров документов, который позволяет их классификацию со сниженным влиянием шумов магнитооптического преобразования, чувствительностью к изменению параметров намагничивания и неоднородностей плотности печати. Усовершенствован метод магнитооптического топографирования, что позволяет получать сигнал двумерного распределения рассеянного магнитного поля документов в матричной цифровой форме. Предложена методика оценки чувствительности и разрешающей способности телевизионной системы магнитооптического контроля. Проведено комплексное экспериментальное исследование теоретических наработок. Разработанные методы позволяют повысить достоверность магнитного контроля (выявления фальсификации) документов, как изготовленных промышленным методом (банкноты и защищенные бланки) так и общедоступным (печать бытовой оргтехникой) за счет выполнения количественного контроля их магнитных параметров. При этом телевизионные системы, реализующие предложенные методы, сохраняют возможность качественного топологического и трасологического исследования, т. е. в отличии от известных обеспечивают комплексный магнитный контроль документов.
36
Muldoon, Cecilia. "Control and manipulation of cold atoms in optical tweezers." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:920933c8-441c-4d59-a4f4-87f8c799a820.
Повний текст джерелаАнотація:
The ability to address and manipulate individual information carriers in a deterministic, coherent, and scalable manner is a central theme in quantum information processing. Neutral atoms trapped by laser light are amongst the most promising candidates for storing and processing information in a quantum computer or simulator, so a scalable and flexible scheme for their control and manipulation is paramount. This thesis demonstrates a fast and versatile method to address and dynamically control the position (the motional degrees of freedom) of neutral atoms trapped in optical tweezers. The tweezers are generated by using the direct image of a Spatial Light Modulator (SLM) which can control and shape a large number of optical dipole-force traps. Trapped atoms adapt to any change in the potential landscape, such that one can re-arrange and randomly access individual sites within atom-trap arrays. A diffraction limited imaging system is used to map the intensity distribution of the SLM onto a cloud of cold atoms captured and cooled using a Magneto Optical Surface Trap (MOST).
37
Reed, Darren James. "Observing and quoting newsgroup messages : method and phenomenon in the hermeneutic spiral." Thesis, Loughborough University, 2002. https://dspace.lboro.ac.uk/2134/6887.
Повний текст джерела
38
Aiken, John Charles. "The development of a colour liquid crystal display spatial light modulator and applications in polychromatic optical data processing." Thesis, Queen's University Belfast, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326384.
Повний текст джерела
39
Leedumrongwatthanakun, Saroch. "Quantum information processing with a multimode fibre." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS526.
Повний текст джерелаАнотація:
Le transport à haut débit de données à travers des fibres optiques grâce au multiplexage spatial est en pratique limité par la diaphonie modale. Au lieu de considérer ce couplage modal comme une limitation, nous exploitons ici ce mélange de modes comme une ressource. Nous mettons en oeuvre un réseau optique linéaire programmable basé sur le concept de design photonique inverse, exploitant les techniques de mise en forme du front d’onde. Nous démontrons la manipulation d’interférences quantiques à deux photons sur divers réseaux linéaires, comprenant des degrés de liberté spatiaux et de polarisations. En particulier, nous vérifions expérimentalement la « zero transmission law » dans des interféromètres de Fourier et de Sylvester, permettant de quantifier le degré d’indiscernabilité d’un état d’entrée. De plus, grâce à la possibilité de mettre en oeuvre un réseau non unitaire, nous mettons en évidence l’anti-coalescence de photons dans toutes les configurations de sortie, et réalisons une expérience d’absorption cohérente. Nous démontrons ainsi l’aspect reconfigurable de l’implémentation de tels réseaux optiques linéaires dans des fibres multimodes. De plus, nous étudions les propriétés statistiques du speckle à un et à deux photons générés à partir de divers états d’entrée, après propagation dans une fibre multimode. Ces propriétés statistiques du speckle peuvent être utilisées pour extraire des informations sur la dimensionnalité, la pureté et l’indiscernabilité d’un état quantique inconnu, permettant ainsi leur classification. Ce travail met en évidence le potentiel du contrôle de front d’onde en milieux complexes pour le traitement quantique de l’informationTransport of information through a multimode optical fibre raises challenges when one wants to increase the data traffic using many spatial modes due to modal cross-talk and dispersion. Instead of considering those complex mixing of modes as a detrimental process, in this dissertation, we harness its mode mixing to process quantum optical information. We implement a reconfigurable linear optical network, a fundamental building block for scalable quantum technologies, based on an inverse photonic approach exploiting the technology of wavefront shaping. We experimentally demonstrate manipulation of two-photon quantum interference on various linear optical networks across both spatial and polarization degrees of freedom. In particular, we experimentally show the zero-transmission law in Fourier and Sylvester interferometers, which are used to certificate the degree of indistinguishability of an input state. Moreover, thanks to the ability to implement a non-unitary network, we observe the photon anti-coalescence effect in all output configurations, as well as the realization of a tunable coherent absorption experiment. Therefore, we demonstrate the reconfigurability, accuracy, scalability and robustness of the implemented linear optical networks for quantum information processing. Furthermore, we study the statistical properties of one-and two-photon speckles generated from various ground-truth states of light after propagating through a multimode fibre. These statistical properties of speckles can be used to extract information about the dimensionality, purity, and indistinguishability of an unknown input state of light, therefore allowing for state classification. Our results highlight the potential of complex media combined with wavefront shaping for quantum information processing
40
Whitbread, P. J. "Multi-spectral texture : improving classification of multi-spectral images by the integration of spatial information /." Title page, abstract and contents only, 1992. http://web4.library.adelaide.edu.au/theses/09PH/09phw5792.pdf.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1994?One computer disk in pocket inside back cover. System requirements for accompanying computer disk: Macintosh computer. Includes bibliographical references (leaves 148-160).
41
Raguet, Hugo. "A Signal Processing Approach to Voltage-Sensitive Dye Optical Imaging." Thesis, Paris 9, 2014. http://www.theses.fr/2014PA090031/document.
Повний текст джерелаАнотація:
L’imagerie optique par colorant potentiométrique est une méthode d’enregistrement de l’activité corticale prometteuse, mais dont le potentiel réel est limité par la présence d’artefacts et d’interférences dans les acquisitions. À partir de modèles existant dans la littérature, nous proposons un modèle génératif du signal basé sur un mélange additif de composantes, chacune contrainte dans une union d’espaces linéaires déterminés par son origine biophysique. Motivés par le problème de séparation de composantes qui en découle, qui est un problème inverse linéaire sous-déterminé, nous développons : (1) des régularisations convexes structurées spatialement, favorisant en particulier des solutions parcimonieuses ; (2) un nouvel algorithme proximal de premier ordre pour minimiser efficacement la fonctionnelle qui en résulte ; (3) des méthodes statistiques de sélection de paramètre basées sur l’estimateur non biaisé du risque de Stein. Nous étudions ces outils dans un cadre général, et discutons leur utilité pour de nombreux domaines des mathématiques appliqués, en particulier pour les problèmes inverses ou de régression en grande dimension. Nous développons par la suite un logiciel de séparation de composantes en présence de bruit, dans un environnement intégré adapté à l’imagerie optique par colorant potentiométrique. Finalement, nous évaluons ce logiciel sur différentes données, synthétiques et réelles, montrant des résultats encourageants quant à la possibilité d’observer des dynamiques corticales complexesVoltage-sensitive dye optical imaging is a promising recording modality for the cortical activity, but its practical potential is limited by many artefacts and interferences in the acquisitions. Inspired by existing models in the literature, we propose a generative model of the signal, based on an additive mixtures of components, each one being constrained within an union of linear spaces, determined by its biophysical origin. Motivated by the resulting component separation problem, which is an underdetermined linear inverse problem, we develop: (1) convex, spatially structured regularizations, enforcing in particular sparsity on the solutions; (2) a new rst-order proximal algorithm for minimizing e›ciently the resulting functional; (3) statistical methods for automatic parameters selection, based on Stein’s unbiased risk estimate.We study thosemethods in a general framework, and discuss their potential applications in variouselds of applied mathematics, in particular for large scale inverse problems or regressions. We develop subsequently a soŸware for noisy component separation, in an integrated environment adapted to voltage-sensitive dye optical imaging. Finally, we evaluate this soŸware on dišerent data set, including synthetic and real data, showing encouraging perspectives for the observation of complex cortical dynamics
42
Allard, Christopher E. "Development of a non-destructive optical method to measure residual stress in thin rectangular samples employing digital image processing." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/20645.
Повний текст джерела
43
WEST, KAREN FRANCES. "AN EXTENSION TO THE ANALYSIS OF THE SHIFT-AND-ADD METHOD: THEORY AND SIMULATION (SPECKLE, ATMOSPHERIC TURBULENCE, IMAGE RESTORATION)." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/188021.
Повний текст джерелаАнотація:
The turbulent atmosphere degrades images of objects viewed through it by introducing random amplitude and phase errors into the optical wavefront. Various methods have been devised to obtain true images of such objects, including the shift-and-add method, which is examined in detail in this work. It is shown theoretically that shift-and-add processing may preserve diffraction-limited information in the resulting image, both in the point source and extended object cases, and the probability of ghost peaks in the case of an object consisting of two point sources is discussed. Also, a convergence rate for the shift-and-add algorithm is established and simulation results are presented. The combination of shift-and-add processing and Wiener filtering is shown to provide excellent image restorations.
44
Wang, Zhao. "Intravascular Optical Coherence Tomography Image Analysis." Case Western Reserve University School of Graduate Studies / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1364673682.
Повний текст джерела
45
Hrůza, Libor. "Koherentní analogové zpracování optické informace." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217466.
Повний текст джерелаАнотація:
In my essay I show Fourier transform theory and applications in context with difraction theory especially Fraunhofer difraction. In part of the experiment, I set up an optical signal processing system. I take the Fourier transform of an input signal using a lens, filter the transform by placing various filters at the Fourier plane, and take the inverse transform. A simple optical bench consists of a laser, to produce a parallel, monochromatic beam which illuminates a specific area of the micrograph. Lens to focus the Fraunhofer diffraction pattern in the back focal plane of the lens. Mask transit contrived light or block out most of the noise in the diffraction pattern arising from image features. A reconstruction lens, placed behind the mask, refocuses the unobstructed rays and forms a filtered image. Optical diffraction provides useful information about the geometrical arrangement of subunits in the specimen. I make experiments for attestation on elementary objects and real images in mathematic program Matlab. From knowledge Fraunhofer difraction and organization of experiment I calculated size of circular object. I show practical using of Fraunhofer difraction and optical filtration. My essay give good introduction to the theory and techniques of optical filtration.
46
Wingen, Georg. "Vertikale Wanderwellenmodulatoren auf Quantenfilmbasis für die optische Informationsverarbeitung - Vertical travelling-wave modulators using quantum-well material for optical information processing." Gerhard-Mercator-Universitaet Duisburg, 2001. http://www.ub.uni-duisburg.de/ETD-db/theses/available/duett-10122001-113233/.
Повний текст джерелаАнотація:
The vertical optical travelling-wave modulator represents a new high-frequency element for optical data processing. The modulator is designed for a wavelength of 1200 nm and combines the layered structure of vertical optical modulators based on pseudomorphic InGaAs/GaAs quantum-wells with microwave lines from the MMIC technology. The quantum confined Stark effect is used to modulate the optical signal. The multiple quantum-well structure is embedded into an asymmetrical Fabry-Perot resonator built from a Bragg reflector and an aluminum layer to increase the electrooptical effect. The modulators produces a reflectivity change of 0,28. Large scale travelling-wave modulators are capable of critical frequencies higher than 40 GHz. By varying the width of the central conductor of the microwave line, the slow-wave factor could be varied experimentally between 4.8 and 12,7. The applied microwave produces a modulation lattice along the microwave line which can be used in a high frequency beam-steering element for optical information processing
47
Alonso, Miguel Jr. "A method for enhancing digital information displayed to computer users with visual refractive errors via spatial and spectral processing." FIU Digital Commons, 2007. http://digitalcommons.fiu.edu/etd/1112.
Повний текст джерелаАнотація:
This research pursued the conceptualization, implementation, and verification of a system that enhances digital information displayed on an LCD panel to users with visual refractive errors. The target user groups for this system are individuals who have moderate to severe visual aberrations for which conventional means of compensation, such as glasses or contact lenses, does not improve their vision.
This research is based on a priori knowledge of the user's visual aberration, as measured by a wavefront analyzer. With this information it is possible to generate images that, when displayed to this user, will counteract his/her visual aberration. The method described in this dissertation advances the development of techniques for providing such compensation by integrating spatial information in the image as a means to eliminate some of the shortcomings inherent in using display devices such as monitors or LCD panels. Additionally, physiological considerations are discussed and integrated into the method for providing said compensation.
In order to provide a realistic sense of the performance of the methods described, they were tested by mathematical simulation in software, as well as by using a single-lens high resolution CCD camera that models an aberrated eye, and finally with human subjects having various forms of visual aberrations. Experiments were conducted on these systems and the data collected from these experiments was evaluated using statistical analysis.
The experimental results revealed that the pre-compensation method resulted in a statistically significant improvement in vision for all of the systems. Although significant, the improvement was not as large as expected for the human subject tests. Further analysis suggest that even under the controlled conditions employed for testing with human subjects, the characterization of the eye may be changing. This would require real-time monitoring of relevant variables (e.g. pupil diameter) and continuous adjustment in the pre-compensation process to yield maximum viewing enhancement.
48
Rundin, Patrick. "Evaluation of a statistical method to use prior information in the estimation of combustion parameters." Thesis, Linköping University, Department of Electrical Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-6255.
Повний текст джерелаАнотація:
Ion current sensing, where information about the combustion process in an SI-engine is gained by applying a voltage over the spark gap, is currently used to detect and avoid knock and misfire. Several researchers have pointed out that information on peak pressure location and air/fuel ratio can be gained from the ion current and have suggested several ways to estimate these parameters.
Here a simplified Bayesian approach was taken to construct a lowpass-like filter or estimator that makes use of prior information to improve estimates in crucial areas. The algorithm is computationally light and could, if successful, improve estimates enough for production use.
The filter was implemented in several variants and evaluated in a number of simulated cases. It was found that the proposed filter requires a number of trade-offs between variance, bias, tracking speed and accuracy that are difficult to balance. For satisfactory estimates and trade-off balance the prior information must be more accurate than was available.
It was also found that similar a task, constructing a general Bayesian estimator, has already been tackled in the area of particle filtering and that there are promising and unexplored possibilities there. However, particle filters require computational power that will not be available to production engines for some years.
Vid jonströmsmätning utvinns information om förbränningsprocessen i en bensinmotor genom att en spänning läggs över gnistgapet och den resulterande strömmen mäts. Jonströmsmätning används idag för knack- och feltändningsdetektion. Flera forskare har påpekat att det finns än mer information i jonströmmen, bl.a. om bränsleblandningen och cylindertrycket och har även föreslagit metoder för att utvinna och använda den informationen för skattning av dessa parametrar.
Här presenteras en förenklad Bayesisk metod i form av en lågpassfilter-liknande skattare som använder förkunskap till att förbättra estimat på relevanta områden. Algoritmen är beräkningsmässigt lätt och kan, om den är framgångsrik, leverera skattningar av förbränningsparametrar som är tillräckligt bra för att användas för sluten styrning av en bensinmotor.
Skattaren, eller filtret, implementerades i flera varianter och utvärderades i ett antal simulerade fall. Resultaten visade på att flera svåra avvägningar måste göras mellan förbättring i varians, avvikelse och följning eftersom förbättring i den ena ledde till försämring i de andra. För att göra dessa avvägningar och få goda skattningar krävs bättre förhandskunskap och mätdata än vad som var tillgängligt.
Bayesisk skattning är ett stort befintligt område inom statistik och signalbehandling och den mest generella skattaren är partikelfiltret som har många intressanta tillämpningar och möjligheter. De har hittills inte använts inom skattning av förbränningsparametrar och har således go potential för framtida utveckling. De är dock beräkningsmässigt tunga och kräver beräkningsresurser utöver vad som är tillgängliga i ett motorstyrsystem idag.
49
Jaisimha, M. Y. "Compound document retrieval in noisy environments /." Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/6007.
Повний текст джерела
50
Cohn, Trevor A. "Scaling conditional random fields for natural language processing /." Connect to thesis, 2007. http://eprints.unimelb.edu.au/archive/00002874.
Повний текст джерела