Rozprawy doktorskie: „Quantum optics”

1

Gao, Xuesong. "Quantum Nonlinear Optics". University of Dayton / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1564662783494271.

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Garrido, Mauricio. "Quantum Optics in Coupled Quantum Dots". Ohio University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1273589966.

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3

Hessmo, Björn. "Quantum optics in constrained geometries". Doctoral thesis, Uppsala University, Department of Quantum Chemistry, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-1208.

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When light exhibits particle properties, and when matter exhibits wave properties quantum mechanics is needed to describe physical phenomena.

A two-photon source produces nonmaximally entangled photon pairs when the source is small enough to diffract light. It is shown that diffraction degrades the entanglement. Quantum states produced in this way are used to probe the complementarity between path information and interference in Young's double slit experiment.

When two photons have a nonmaximally entangled polarization it is shown that the Pancharatnam phase is dependent on the entanglement in a nontrivial way. This could be used for implementing simple quantum logical circuits.

Magnetic traps are capable of holding cold neutral atoms. It is shown that magnetic traps and guides can be generated by thin wires etched on a surface using standard nanofabrication technology. These atom chips can hold and manipulate atoms located a few microns above the surface with very high accuracy. The potentials are very versatile and allows for highly complex designs, one such design implemented here is a beam splitter for neutral atoms. Interferometry with these confined de Broglie is also considered. These atom chips could be used for implementing quantum logical circuits.

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4

Stock, Ryan. "Silicon-based quantum optics and quantum computing". Thesis, Cardiff University, 2018. http://orca.cf.ac.uk/111871/.

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In this thesis is presented a brief review of quantum computing, the DiVincenzo criteria, and the possibility of using a solid state system for building a quantum computing architecture. Donor electron systems in silicon are discussed, before chalcogen, \deep", double donors are suggested as a good candidate for fulfilment of the criteria; the optically driven Stoneham proposal, where the spin-spin interaction between two donor electron spin qbits is mediated by the optically controlled, excited, state of a third donor electron, forms the basis of this [1]. Coherence lifetimes are established as a vital requirement of a quantum bit, but radiative lifetimes must also be long. If the spin-spin interaction between qbits is decreased, or turned off, by the de-excitation of the mediating donor electron then the coherence of the qbit is rendered irrelevant; de-excitation will ruin quantum computations that depend upon an interaction that only happens when the mediating electron is in an excited state. Effective mass theory is used to estimate excited state donor, 2P, wavefunctions for selenium doped silicon, and recent Mott semiconductor to metal transition doping data [2] is used to scale the spatial extent of the 1S(A1) ground state wavefunction. Using these wavefunctions, the expected radiative lifetimes are then calculated, via Fermi's golden rule, to be between 9 ns and 17 ns for the 2P0 state, and 12 ns to 20 ns for the 2P_1 state. Fourier Transform InfraRed (FTIR) absorbance spectroscopy is used to determine the optical transitions for selenium donors in silicon, this has allowed agreement between literature, measured, and effective mass theory energy values for the particular samples measured. FTIR time resolved spectroscopy has then been used to measure the radiative emission spectrum of selenium doped silicon samples at 10-300K, following a 1220 nm laser pulse. Fitting to the exponentially decaying emission data, selenium radiative lifetimes as long as 80 ns are found; for the 2P0 to 1S(A1) transition in an atomic selenium donor complex at 10K. A factor of between 4 and 8 agreement is found between calculated and measured radiative lifetimes. This offers the possibility of nanosecond scale donor electron coherence times for chalcogen dopants in silicon.

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5

Ekert, Artur Konrad. "Correlations in quantum optics". Thesis, University of Oxford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293479.

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6

Htoon, Han. "Studies on quantum coherence phenomena of self-assembled quantum dots". Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3037502.

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7

HOLM, DAVID ALLEN. "QUANTUM THEORY OF MULTIWAVE MIXING (RESONANCE FLUORESCENCE, SATURATION SPECTROSCOPY, MODULATION, PHASE CONJUGATION, QUANTUM NOISE)". Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/187980.

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This dissertation formulates and applies a theory describing how one or two strong classical waves and one or two weak quantum mechanical waves interact in a two-level medium. The theory unifies many topics in quantum optics, such as resonance fluorescence, saturation spectroscopy, modulation spectroscopy, the build up of laser and optical bistability instabilities, and phase conjugation. The theory is based on a quantum population pulsation approach that resembles the semiclassical theories, but is substantially more detailed. Calculations are performed to include the effects of inhomogeneous broadening, spatial hole burning, and Gaussian transverse variations. The resonance fluorescence spectrum in a high finesse optical cavity is analyzed in detail, demonstrating how stimulated emission and multiwave processes alter the spectrum from the usual three peaks. The effects of quantum noise during the propagation of weak signal and conjugate fields in phase conjugation and modulation spectroscopy are studied. Our analysis demonstrates that quantum noise affects not only the intensities of the signal and conjugate, but also their relative phase, and in particular we determine a quantum limit to the semiclassical theory of FM modulation spectroscopy. Finally, we derive the corresponding theory for the two-photon, two-level medium. This yields the first calculation of the two-photon resonance fluorescence spectrum. Because of the greater number of possible interactions in the two-photon two-level model, the theoretical formalism is considerably more complex, and many effects arise that are absent in the one-photon problem. We discuss the role of the Stark shifts on the emission spectrum and show how the Rayleigh scattering is markedly different.

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8

Bocquillon, Erwann. "Electron quantum optics in quantum Hall edge channels". Paris 6, 2012. http://www.theses.fr/2012PA066692.

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Cette thèse est consacrée à la manipulation d'excitations mono-électroniques dans un conducteur quantique balistique, par l'implémentation d'expériences d'optique quantique électronique avec la résolution d'une charge élémentaire. Une capacité mésoscopique produit à la demande des excitations monoélectroniques dans le canal de bord externe de l'effet Hall quantique. Nous mesurons les fluctuations de courant après partitionnement des excitations sur une lame séparatrice électronique, dans un analogue de l'expérience de Hanbury-Brown & Twiss, afin de révéler les excitations neutres (paires électron/trou) qui peuvent accompagner la charge produite. Les excitations thermiques dans la mer de Fermi sont alors responsables d'interférences à deux particules qui permettent d'obtenir des informations sur la distribution en énergie des quasiparticules émises par la source. A l'aide de deux sources indépendantes et synchronisées, nous générons deux quasi-particules indiscernables, qui interfèrent sur une lame séparatrice dans un analogue de l'expérience de Hong-Ou-Mandel. La visibilité de ce phénomène est possiblement limité par la décohérence des paquets d'ondes électroniques par interaction avec l'environnement, notamment les autres canaux de bords. En mesurant le couplage capacitif entre deux canaux de bords co-propageant, nous caractérisons les effets de l'interaction coulombienne et mettons en évidence un mode neutre de propagation. Ces expériences constituent les premières implémentations d'expériences d'optique quantique électronique avec des charges uniques, et permettent d'envisager des expériences plus complexes comme la tomographie d'un paquet d'onde mono-électronique
This thesis is devoted to the implementation of quantum optics experiments in a ballistic quantum conductor, with single charge resolution. A mesoscopic capacitor produces on-demand single-electron excitations in the outermost edge channel of quantum Hall effect. We measure current fluctuations after partitioning of excitations on an electronic beamsplitter, in analogy with the Hanbury-Brown & Twiss experiment, so as to unveil neutral excitations (electron/holes pairs) that can accompany the emission of the charge. Thermal excitations in the Fermi sea are then responsible for two-particle interferences that yield information on the energy distribution of the generated quasiparticles. Using two independent and synchronized sources, we generate two indistinguishable quasiparticles that interfere on a beamsplitter as in the Hong-Ou-Mandel experiment. The visibility of this phenomenon could be limited by decoherence of the wavepackets due to interactions with the environment and especially with other co-propagating edge channels. By measuring the capacitive coupling between two co-propagating edge channels, we characterize the effects of Coulomb interaction on propagation and highlight a neutral mode of propagation. These experiments constitute the first implementations of electron quantum optics experiments with single charges. They pave the way to more complex experiments such as the tomography of a mono-electronic wavepacket

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9

Zhang, Zheshen. "New techniques for quantum communication systems". Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42843.

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Although mathematical cryptography has been widely used, its security has only been proven under certain assumptions such as the computational power of opponents. As an alternative, quantum communication, in particular quantum key distribution (QKD) can get around unproven assumptions and achieve unconditional security. However, the key generation rate of practical QKD systems is limited by device imperfections, excess noise from the quantum channel, limited rate of true random-number generation, quantum entanglement preparation, and/or post-processing efficiency. This dissertation contributes to improving the performance of quantum communication systems. First, it proposes a new continuous-variable QKD (CVQKD) protocol that loosens the efficiency requirement on post-processing, a bottleneck for long-distance CVQKD systems. It also demonstrates an experimental implementation of the proposed protocol. To achieve high rates, the CVQKD experiment uses a continuous-wave local oscillator (CWLO). The excess noise caused by guided acoustic-wave Brillioun scattering (GAWBS) is avoided by a frequency-shift scheme, resulting in a 32 dB noise reduction. The statistical distribution of the GAWBS noise is characterized by quantum tomography. Measurements show Gaussian statistics upto 55 dB of dynamical range, which validates the security calculations in the proposed CVQKD protocol. True random numbers are required in quantum and classical cryptography. A second contribution of this thesis is that it experimentally demonstrates an ultrafast quantum random-number generator (QRNG) based on amplified spontaneous emission (ASE). Random numbers are produced by a multi-mode photon counting measurement on ASE light. The performance of the QRNG is analyzed with quantum information theory and verified with NIST standard random-number test. The QRNG experiment demonstrates a random-number generation rate at 20 Gbits/s. Theoretical studies show fundamental limits for such QRNGs. Quantum entanglement produced in nonlinear optical processes can help to increase quantum communication distance. A third contribution is the research on nonlinear optics of graphene, a novel 2D material with unconventional physical properties. Based on a quantum-dynamical model, optical responses of graphene are derived, showing for the first time a link between the complex linear optical conductivity and the quantum decoherence. Nonlinear optical responses, in particular four-wave mixing, is studied for the first time. The theory predicts saturation effects in graphene and relates the saturation threshold to the ultrafast quantum decoherence and carrier relaxation in graphene. For the experimental part, four-wave mixing in graphene is demonstrated. Twin-photon production in graphene is under investigation.

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10

Liu, Xunmimg. "Nonlinear dynamics in quantum optics /". St. Lucia, Qld, 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17835.pdf.

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11

Rippin, Michael Andrew. "Quantum optics of tailored cavities". Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242050.

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12

D'Arcy, Michael Brendan. "Quantum chaos in atom optics". Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249527.

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13

Linington, Ian. "Quantum optics with dynamic environments". Thesis, University of Sussex, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442428.

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14

Chille, Vanessa. "Quantum optics with structured light". Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066358/document.

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La présente thèse a pour objectif d'analyser la lumière structurée non-classique et ses caractéristiques. L'optique quantique et la lumière structurée sont deux sujets qui font l'objet d'examens nombreux. Ils sont néanmoins rarement examinés en combinaison. Les propriétés quantiques de la lumière structurée sont moins bien étudiées qu'ils devraient l'être. Par la lumière structurée nous entendons les champs lumineux qui montrent une structure transverse complexe de l'intensité, la phase ou la polarisation. Nous voulons lier les deux sujets de l'optique quantique et la lumière structurée dans la présente thèse. Dans ce but, nous générons expérimentalement des champs lumineux structurés non-classiques. En particulier, nous réalisons une expérience qui permet de générer des faisceaux vectoriels vectoriels - c'est-à-dire des faisceaux lumineux dont l'état de polarisation présente une structure transverse complexe - qui montrent une réduction du bruit quantique. En outre, nous étudions théoriquement les propriétés spatiales de faisceaux lumineux, ainsi que leur bruit. Plus spécifiquement, nous analysons l'incertitude quantique dans la largeur d'un faisceau lumineux. Pour prouver la faisabilité de la vérification expérimentales de nos résultats théoriques, nous réalisons des simulations pour la mesure de paramètres spatiales utilisant un détecteur mulitpixels
This thesis aims at learning more about nonclassical structured light. Quantum optics and structured light are two topics that are subject to countless scientific examinations. However, they are very rarely combined and the quantum properties of structured light are not as thoroughly studied as they deserve. By structured light, we mean any light fields with complex transverse distributions of intensity, phase or polarization. We want to link the topics of quantum optics and structured light in this thesis. For this purpose, we experimentally generate particular nonclassical structured light fields. In particular, we construct an experimental setup that enables us, in principle, to produce arbitrary amplitude squeezed vector beams, i.e. light beams with a complex transverse structure of the state of polarization. Furthermore, we analyze spatial properties of light beams, and their quantum noise theoretically. We specifically perform theoretical examinations of the quantum noise in the width of a light beam. To show the feasibility of an experimental verification of our theoretical results, we conduct simulations for the measurement of spatial parameters of a beam's cross-section by a multipixel detector

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15

Vedovato, Francesco. "Quantum Optics Experiments in Space". Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3424875.

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Space has always been a primary source of inspiration for the development of the scientific, technological, artistic, philosophical and religious thinking of the whole humankind. Space explorations marked the history of the XX century, bringing an incredible technological advancement and allowing to investigate the natural phenomena over scales and into details which are simply not available on Earth. Nowadays, the Space is the benchmark of the new quantum revolution, which promises to change the way we communicate, measure and calculate, thank to the exploitation and the control of what happens at the microscopic scale. Indeed, the quantum theory, born at the beginning of the XX century to describe the behavior of the elementary particles of Nature, has reached today an incredible reliability. As any scientific theory, Quantum Mechanics is valid within the limits in which it has been experimentally verified, and the Space is the main stage where to validate quantum predictions at large scales, in a domain that is completely different with respect to the microscopic one from which it moved. The technological advances in photonics, which allows the manipulation and the control of the single quanta of light, the photons, make today feasible fundamental tests of Quantum Mechanics in Space, experiments to investigate, for example, if entanglement is preserved along thousands of kilometers or if the wave-particle duality survives even after a Space trip. Furthermore, Space makes available relativistic regimes, in which the velocities and the distances could allow to experimentally investigate the unresolved puzzle of modern physics, that is, the interplay between Quantum Mechanics and gravitation. For these reasons, this thesis is dedicated to the Quantum Optics experiment in Space I have been involved during my PhD.
Da sempre lo Spazio è stato fonte di ispirazione per lo sviluppo del pensiero scientifico, tecnologico, artistico, filosofico e religioso per tutta l’umanità. Le esplorazioni spaziali hanno segnato la storia del XX secolo, portando un incredibile sviluppo tecnologico e permettendo di investigare i fenomeni naturali a scale e dettagli che semplicemente non si possono ottenere restando sulla Terra. Oggi lo Spazio è il banco di prova di una nuova rivoluzione quantistica, che annuncia di poter cambiare il modo in cui oggigiorno comunichiamo, misuriamo e facciamo di conto, grazie all’utilizzo e al controllo di ciò che avviene su scala microscopica. Infatti, la teoria quantistica, nata all’inizio del XX secolo proprio per descrivere il comportamento delle particelle elementari costituenti la Natura, ha raggiunto oggi un grado di affidabilità strabiliante. Come qualsiasi teoria scientifica infatti, la Meccanica Quantistica è valida entro i confini in cui è stata verificata sperimentalmente, e lo Spazio è il palcoscenico principale in cui poter validare le predizioni della teoria quantistica a grandi scale, in un dominio completamente diverso da quello microscopico entro cui è stata ideata. I progressi tecnologici nel campo della fotonica, che permette la manipolazione e il controllo dei singoli quanti di luce, i fotoni, rendono oggi fattibili test fondamentali di Meccanica Quantistica nello Spazio, esperimenti in cui indagare, per esempio, se l’entanglement si mantiene anche a migliaia di chilometri o se il dualismo onda-corpuscolo si manifesta anche dopo un viaggio spaziale. Inoltre, lo Spazio offre di per sé accesso a regimi relativistici in cui le velocità e le distanze in gioco possono permettere di indagare il puzzle irrisolto della fisica moderna, l’unione di Meccanica Quantistica e gravitazione. Per queste ragioni, questa tesi è dedicata agli esperimenti di Ottica Quantistica nello Spazio in cui sono stato coinvolto durante il mio dottorato.

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16

Lipfert, Tobias. "Ordering effects in quantum optics". Thesis, Lille 1, 2019. http://www.theses.fr/2019LIL1R007/document.

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En optique quantique, la nature quantique de la lumière se manifeste dans des effets d’ordonnement d’opérateurs, inexistants en optique classique. Cette thèse est consacrée à une étude détaillée de ce type d’effets d’ordonnement dus à la dynamique des systèmes physiques. Nous considérons deux systèmes en particulier, 1) la conversion paramétrique descendante dans un milieu χ (2), et 2) un ion dans un piège de Paul entraı̂né par un champ classique; décrit par un modèle de Jaynes-Cummings non linéaire. Les effets d’ordonnement dans ces systèmes dynamiques sont étudiés via le développement et l’approximation de Magnus. Dans le scénario de conversion paramétrique descendante, nous considérons deux cas, (i) une pompe monochromatique (où une solution exacte de la dynamique est connue) et (ii) une pompe spectralement large. Pour la pompe monochromatique, nous écrivons explicitement la décomposition de Bloch-Messiah et obtenons les modes propres et les paramètres de compression. Nous comparons ces résultats exacts avec les approximations de Magnus en incluant certains ou aucun effets d’ordonnement. Nous effectuons une analyse similaire pour la pompe spectralement large lorsque la décomposition de Bloch-Messiah ne peut être évaluée que numériquement. Pour le modèle dynamique de Jaynes-Cummings non linéaire, nous analysons, à nouveau, les effets d’ordonnement via des approximations de Magnus et obtenons la solution exacte, qui n’avait pas été publiée dans la littérature auparavant. Enfin, nous évaluons pour la première fois les limites supérieures exactes (qui dépassent les limites suffisantes) de la convergence du développement de Magnus pour les deux modèles dynamiques à solutions exactes
In quantum optics, the quantum nature of light manifests itself in operator ordering effects, nonexistent in classical optics. This thesis is devoted to a detailed study of such ordering effects that are due to the dynamics of physical systems. We consider two systems in particular, 1) parametric down-conversion in a χ(2) medium, and 2) an ion in a Paul trap driven by a classical field; described by a nonlinear Jaynes-Cummings model. Ordering effects in these dynamical systems are studied via the Magnus expansion and approximation. In the parametric down-conversion scenario we consider two cases, (i) a monochromatic pump (where an exact solution of the dynamics is known), and (ii) a spectrally broad pump. For the monochromatic pump, we write explicitly the Bloch-Messiah decomposition and obtain the squeezing eigenmodes and parameters. We compare these exact results with the Magnus approximations that contain some or no ordering effects. We perform similar analysis for the spectrally broad pump, where the Bloch-Messiah decomposition can only be evaluated numerically. For the dynamics in the nonlinear Jaynes-Cummings model we again analyze ordering effects via Magnus approximations and obtain the exact solution, which has not been published in the literature before. Lastly, we evaluate the exact upper bounds (which exceed sufficient bounds) of convergence of the Magnus expansion for the two models with exact solutions, for the first time

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17

Lipfert, Tobias. "Ordering effects in quantum optics". Electronic Thesis or Diss., Université de Lille (2018-2021), 2019. http://www.theses.fr/2019LILUR007.

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En optique quantique, la nature quantique de la lumière se manifeste dans des effets d’ordonnement d’opérateurs, inexistants en optique classique. Cette thèse est consacrée à une étude détaillée de ce type d’effets d’ordonnement dus à la dynamique des systèmes physiques. Nous considérons deux systèmes en particulier, 1) la conversion paramétrique descendante dans un milieu χ (2), et 2) un ion dans un piège de Paul entraı̂né par un champ classique; décrit par un modèle de Jaynes-Cummings non linéaire. Les effets d’ordonnement dans ces systèmes dynamiques sont étudiés via le développement et l’approximation de Magnus. Dans le scénario de conversion paramétrique descendante, nous considérons deux cas, (i) une pompe monochromatique (où une solution exacte de la dynamique est connue) et (ii) une pompe spectralement large. Pour la pompe monochromatique, nous écrivons explicitement la décomposition de Bloch-Messiah et obtenons les modes propres et les paramètres de compression. Nous comparons ces résultats exacts avec les approximations de Magnus en incluant certains ou aucun effets d’ordonnement. Nous effectuons une analyse similaire pour la pompe spectralement large lorsque la décomposition de Bloch-Messiah ne peut être évaluée que numériquement. Pour le modèle dynamique de Jaynes-Cummings non linéaire, nous analysons, à nouveau, les effets d’ordonnement via des approximations de Magnus et obtenons la solution exacte, qui n’avait pas été publiée dans la littérature auparavant. Enfin, nous évaluons pour la première fois les limites supérieures exactes (qui dépassent les limites suffisantes) de la convergence du développement de Magnus pour les deux modèles dynamiques à solutions exactes
In quantum optics, the quantum nature of light manifests itself in operator ordering effects, nonexistent in classical optics. This thesis is devoted to a detailed study of such ordering effects that are due to the dynamics of physical systems. We consider two systems in particular, 1) parametric down-conversion in a χ(2) medium, and 2) an ion in a Paul trap driven by a classical field; described by a nonlinear Jaynes-Cummings model. Ordering effects in these dynamical systems are studied via the Magnus expansion and approximation. In the parametric down-conversion scenario we consider two cases, (i) a monochromatic pump (where an exact solution of the dynamics is known), and (ii) a spectrally broad pump. For the monochromatic pump, we write explicitly the Bloch-Messiah decomposition and obtain the squeezing eigenmodes and parameters. We compare these exact results with the Magnus approximations that contain some or no ordering effects. We perform similar analysis for the spectrally broad pump, where the Bloch-Messiah decomposition can only be evaluated numerically. For the dynamics in the nonlinear Jaynes-Cummings model we again analyze ordering effects via Magnus approximations and obtain the exact solution, which has not been published in the literature before. Lastly, we evaluate the exact upper bounds (which exceed sufficient bounds) of convergence of the Magnus expansion for the two models with exact solutions, for the first time

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18

Agnew, Amalia. "Quantum-Chemical Investigations of Second- and Third-Order Nonlinear Optical Chromophores for Electro-Optic and All-Optical Switching Applications". Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11575.

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The past decades have witnessed the development of new materials with large nonlinear optical properties, which have made them attractive candidats for a broad spectrum of breakthrough applications in the electro-optic and photonic fields (e.g., telecommunication and computing). A deeper understanding of the relationship between, on the one hand, the chemical structure and, on the other hand, the electronic and (linear and nonlinear) optical properties has proven useful for the rational design of new efficient materials. Reaching such an understanding has attracted major interest in the scientific community worldwide in both academia and industry. Therefore, the development of new efficient NLO chromophores and materials along with commercial devices of high quality is helped via the establishment of multidisciplinary research teams combining: (i) the theoretical modeling using quantum-chemical computational calculations; (ii) the organic synthesis; (iii) the optical characterization; and (iv) the device fabrication. In this dissertation, quantum-chemistry is used to evaluate the second- and third-order NLO properties of series of new chromophores and take advantage of a feedback loop with the experimental team to understand the structure-property relationships.

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Dynes, James Francis. "Quantum optics in intersubband transitions in semiconductor quantum wells". Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413944.

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20

Chabaud, Ulysse. "Continuous variable quantum advantages and applications in quantum optics". Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS066.

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La physique quantique a apporté une révolution conceptuelle quant à la nature de notre monde et apporte aujourd’hui une révolution technologique. En effet, l’utilisation de l’information quantique promet des applications surclassant les machines actuelles, dites classiques. La théorie de l’information quantique en variable continue porte sur l’étude des possibilités qu’offre l’encodage de l’information dans des degrés de liberté continus de systèmes quantiques. Mathématiquement, cette théorie étend l’étude de l'information quantique aux états quantiques dans des espaces de Hilbert de dimension infinie. Elle offre des perspectives différentes de l’information quantique en variable discrète et est notamment adaptée à la description des états quantiques de lumière. L’optique quantique est ainsi une plateforme expérimentale naturelle pour développer des applications quantiques en variable continue. La thèse s’articule autour de trois questions principales : d’où provient l’avantage quantique, c est-à-dire la capacité des machines quantiques à surclasser les machines classiques ? Comment s assurer du bon fonctionnement d une machine quantique ? Quels avantages peut-on tirer de l'utilisation de l’information quantique ? Ces trois questions sont au cœur du développement des technologies quantiques, et nous y apportons plusieurs réponses dans le cadre de la théorie de l’information quantique en variable continue et de l’optique quantique linéaire
Quantum physics has led to a revolution in our conception of the nature of our world and is now bringing about a technological revolution. The use of quantum information promises indeed applications that outperform those of today's so-called classical devices. Continuous variable quantum information theory refers to the study of quantum information encoded in continuous degrees of freedom of quantum systems. This theory extends the mathematical study of quantum information to quantum states in Hilbert spaces of infinite dimension. It offers different perspectives compared to discrete variable quantum information theory and is particularly suitable for the description of quantum states of light. Quantum optics is thus a natural experimental platform for developing quantum applications in continuous variable. This thesis focuses on three main questions: where does a quantum advantage, that is, the ability of quantum machines to outperform classical machines, come from? How to ensure the proper functioning of a quantum machine? What advantages can be gained in practice from the use of quantum information? These three questions are at the heart of the development of future quantum technologies and we provide several answers within the frameworks of continuous variable quantum information and linear quantum optics

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21

Pope, Damian. "Contrasting quantum mechanics to local hidden variables theories in quantum optics and quantum information science /". [St. Luica, Qld.], 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16765.pdf.

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22

Johnston, Wesley James. "Nonlinear optics in Bragg-spaced quantum wells". Diss., University of Iowa, 2010. https://ir.uiowa.edu/etd/826.

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Bragg spaced quantum wells represent a unique class of resonant photonic materials, wherein a photonic bandgap is created by the periodic spacing of quantum wells and the associated variation in the complex susceptibility (index and absorption) of the material. Interest in BSQWs has grown in the past decade due to their large ultrafast nonlinearities and the corresponding large ultrafast reflectivity changes and transmissivity. These nonlinearities are of particular interest in areas of communication technology, where ultrafast all-optical logic components have become increasingly in demand. This research will further investigate BSQWs and the for the first time effects of spin-dependent nonlinear excitation on their photonic band structures. It will also investigate how these effects can be used in all-optical polarization switching and tunable optical buffer (slow light) applications.

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Román, Rodríguez Víctor. "Quantum Optics Systems for Long-Distance Cryptography and Quantum Networks". Electronic Thesis or Diss., Sorbonne université, 2022. http://www.theses.fr/2022SORUS224.

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La thèse est divisée en deux parties : La première partie s'inscrit dans le domaine de la cryptographie quantique. Dans cette partie, nous développons une étude théorique d'un protocole de distribution de clés quantiques (QKD) dans le scénario d'une liaison satellite-station terrestre. Nous considérons l'ajout des fluctuations quantiques du canal et la possibilité de succès du protocole dans le cadre de variables continues dans une implémentation avec des technologies de pointe. Nous montrons la faisabilité de CVQKD dans le contexte du satellite. Dans la deuxième partie, nous construisons, à partir de zéro, une source d'états quantiques de la lumière de type graphe à variables continues en utilisant des guides d'ondes non linéaires. Ces états sont essentiels pour la mise en œuvre de protocoles de communication et de calcul quantique, car ils peuvent être considérés comme des réseaux quantiques. Nous réalisons une étude théorique des états quantiques multimodes de la lumière après l'interaction dans un guide d'ondes non linéaire qui nous aide à concevoir l'expérience. Enfin, nous présentons les résultats expérimentaux qui démontrent les premiers résultats sur la source quantique d'états quantiques de lumière multimode à variation continue, mesurant jusqu'à 11 états de lumière thermique comprimée
The thesis is divided into two parts: The first part is in the field of Quantum Cryptography. In this part we develop a theoretical study of a Quantum Key Distribution (QKD) protocol in the scenario of a satellite-ground station link. We consider the addition of quantum channel fluctuations and the possibility of success of the protocol in the framework of continuous variables in an implementation with state-of-the-art technologies. We show the feasibility of CVQKD in the satellite context. In the second part, we build, from scratch, a source of continuous-variable graph-like quantum states of light using nonlinear waveguides. These states are essential for the implementation of communication and quantum computing protocol as they can be seen to be quantum networks. We perform a theoretical study for multimode quantum states of light after the interaction in a non-linear waveguide that help us to design the experiment. Finally we present the experimental results that demonstrate the first results on the quantum source of continuous variable multimode quantum states of light, measuring up to 11 squeezed thermal light states

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Jedrkiewicz, Ottavia. "Theories of atom-field interaction in cavities and retrodiction for quantum communications". Thesis, University of Essex, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340589.

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Jenkins, Stewart David. "Theory of light -atomic ensemble interactions entanglement, storage, and retrieval /". Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-09252006-175848/.

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Thesis (Ph. D.)--Physics, Georgia Institute of Technology, 2007.
Kennedy, T. A. Brian, Committee Chair ; Kuzmich, Alex, Committee Member ; Chapman, Michael S., Committee Member ; Raman, Chandra, Committee Member ; Morley, Thomas D., Committee Member.

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Manzoni, Marco Tommaso. "New systems for quantum nonlinear optics". Doctoral thesis, Universitat Politècnica de Catalunya, 2017. http://hdl.handle.net/10803/461495.

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Photons travelling through free space do not interact with each other. This characteristic makes them perfect candidates to carry quantum information over long distances. On the other hand, processing the information they encode requires interaction mechanisms. In recent years, there have been growing efforts to realize strong, controlled interactions between photons by making them interact with individual atoms, which are intrinsically nonlinear objects. This, and the efforts to understand the phenomena that can emerge, have spawned the new field of`"quantum nonlinear optics." A number of approaches have been pursued to attain near-deterministic atom-photon interactions, including the use of cavities (CQED), of atomic ensembles, and more recently of dielectric nanostructures able to confine light without defocusing, thus enabling the interaction with atoms trapped in the proximity of the structures. While for the CQED case powerful theoretical tools have been developed to treat the interactions of photons, in the case of atomic ensembles, either in free space or coupled to nanophotonic structures, there is a general lack of theoretical methods beyond the linear regime. This relative lack of understanding also implies that there could be rich new physical phenomena that have thus far not been identified. The overall goal of this thesis is to explore these themes in greater detail. In Chapter 2 of this thesis we develop a new formalism to calculate the properties of quantum light when interfaced with atomic ensembles. The method consists of using a "spin model" that maps a quasi one-dimensional (1D) light propagation problem to the dynamics of an open 1D interacting spin system, where all of the photon correlations are obtained from those of the spins. The spin dynamics can be numerically solved using the toolbox of matrix product states (MPS), thus providing a technique to study strongly interacting photons in the true many-body limit. In Chapter 3 we investigate the possibility of creating exotic phases of matter using the recently realized photonic crystal waveguide (PCW)-atoms interface. In particular, we examine the consequences that arise from the strong interatomic forces mediated by the exchange of band gap photons, whose strengths also depend strongly on the internal atomic states (¿spins¿). Taking one realistic model, we show that "quantum crystallization" can occur, in which the emergent spatial orders of atoms depend intricately on the spin correlations. In Chapter 4 we investigate the possibility of implementing second-order nonlinear quantum optical processes with graphene nanostructures, as a more robust alternative to the use of atomic systems. We quantify the second-order nonlinear properties, showing that the tight confinement of surface plasmons (SP) in graphene gives rise to extraordinary interaction strengths at the single-photon level. Finally, we predict that opportunely engineered arrays of graphene nanostructures can provide a second harmonic generation efficiency comparable with that of state-of-the-art nonlinear crystals, with the high Ohmic losses of graphene serving as the fundamental limitation for deterministic processes. In Chapter 5 we investigate a new paradigm for quantum memories of light based upon ordered atomic arrays. In particular, we show that the strong constructive interference in optical emission can give rise to a significantly enhanced atom-light interface, as compared to a standard, disordered atomic ensemble. In the case of a single, 2D atomic layer, we find the impressive result that a memory realized with 16 atoms can have the same storage efficiency as an atomic ensemble with optical depth larger than 100.
Los fotones que viajan por el espacio libre no interactúan entre sí. Esta característica los hace perfectos candidatos para transportar la información cuántica a largas distancias. Por otro lado, el procesamiento de la información que codifican requiere mecanismos de interacción. En los últimos años se han realizado esfuerzos crecientes para realizar interacciones fuertes y controladas entre los fotones y para comprender las leyes subyacentes que describen los fenómenos que pueden surgir, generando así el nuevo campo de la "óptica cuántica no lineal". Mientras que los materiales tridimensionales tienen coeficientes no lineales extremadamente débiles, se pueden obtener interacciones entre los fotones haciéndolos interactuar con átomos individuales, que son objetos intrínsecamente no lineales, teniendo la capacidad de absorber únicamente un solo fotón a la vez. La realización de interacciones determinísticas entre fotones y átomos es uno de los principales retos de la óptica cuántica no lineal. Para eludir las limitaciones debidas a la pequeña sección eficaz óptica de los átomos y el límite de difracción en el espacio libre, se han aplicado diferentes estrategias, entre ellas el uso de cavidades (CQED), de colectividades atómicas y, más recientemente, de nanoestructuras dieléctricas capaces de confinar la luz sin desenfocarse, permitiendo así la interacción con átomos atrapados en la proximidad de esas estructuras. Mientras que para el caso de la CQED se han desarrollado potentes herramientas teóricas para tratar las interacciones de los fotones, en el caso de colectividades atómicas hay una falta general de métodos teóricos más allá del régimen lineal. Esta relativa falta de comprensión también implica que podría haber nuevos fenómenos físicos interesantes que hasta ahora no se han identificado. El objetivo general de esta tesis es explorar estos temas con mayor detalle. En el capítulo 2 de esta tesis desarrollamos un nuevo formalismo para calcular las propiedades de la luz cuántica cuando interactúa con sistemas atómicos. El método consiste en utilizar un"`modelo de espines" que mapea un problema de propagación de luz cuasi unidimensional (1D) a la dinámica de un sistema abierto unidimensional de espines que interactúan entre sí, donde todas las correlaciones de fotones se obtienen a partir de las de los espines. La dinámica de los espines se puede resolver numéricamente utilizando la caja de herramientas de los estados producto de matrices (MPS), proporcionando así una técnica para estudiar los fotones que interactúan fuertemente en el regimen de la física de muchos cuerpos. En el capítulo 3 se investiga la posibilidad de crear fases exóticas de la materia utilizando la interfaz entre guía de ondas de cristales fotónicos (PCW) y átomos recientemente realizada experimentalmente, donde los modos de la banda de frecuencias prohibidas de la PCW se utilizan para mediar las interacciones de largo alcance entre los átomos. Encontramos un rico diagrama de fases de órdenes emergentes. En el capítulo 4 se investiga la posibilidad de implementar procesos ópticos cuánticos no lineales de segundo orden con nano-estructuras de grafeno, como una alternativa más robusta al uso de sistemas atómicos. Cuantificamos las propiedades no lineales de segundo orden, mostrando que el estrecho confinamiento da lugar a extraordinarias fuerzas de interacción a nivel de un solo fotón y predecimos que un diseño apropiado de las nano-estructuras del grafeno permitiría generar el segundo armónico con una eficiencia comparable a la de los cristales no lineales de última generación. En el capítulo 5, investigamos cómo la emisión cooperativa en memorias cuánticas realizadas con reticulos atómicos afecta su eficiencia, encontrando el impresionante resultado de que una memoria realizada con 16 átomos puede tener la misma eficiencia que un gas cuántico atómico de profundidad óptica mayor que 100.

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Berman, D. Ballester. "Quantum optics in tightly confining media". Thesis, Queen's University Belfast, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.546007.

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Stensson, Katarina. "Quantum Optics in 2D Nonlinear Lattices". Thesis, KTH, Tillämpad fysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-145893.

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Rodgers, Peter A. "Time-dependent pulses in quantum optics". Thesis, Queen's University Belfast, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356924.

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Tarzi, S. "Dissipation and amplification in quantum optics". Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/47271.

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Phoenix, Simon James Daniel. "Entropy and disorder in quantum optics". Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/46503.

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Light, Philip Stephen. "Photonic microcells for quantum optics applications". Thesis, University of Bath, 2008. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.512327.

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This thesis presents the development of photonic microcells for use as the host for coherent optics phenomena and related applications. A photonic microcell consists of a length of hollow-core photonic crystal fibre (HC-PCF) with a gas-filled core that is spliced to conventional optical fibre at either end to seal the gas within the fibre. Towards the goal of demonstrating and assessing the coherence properties of quantum optical effects in photonic microcells, the fabrication of two types of HC-PCF is presented. The established photonic bandgap HC-PCF offers extremely low transmission loss of ~10 dB/km over kilometre distances. However, the fibre has a limited transmission bandwidth of ~50 THz and exhibits modal coupling unfavourable for many applications. Work is presented on the tailoring of this fibre by control and shaping of the core-surround in order to improve its modal properties. A second type of HC-PCF is based on a large-pitch lattice, whose guidance relies on a new mechanism. This fibre exhibits a much improved bandwidth (>1000 THz) and has a relatively higher but still practical loss of ~1 dB/m. The development of photonic microcells at microbar pressure level and with low optical insertion loss is shown, an important step in the improvement of the technology for coherent optics applications which will take advantage of the extreme gas-laser interaction efficiency achieved in HC-PCF. Finally, quantum optical effects are demonstrated in HC-PCF and photonic microcells loaded with both the molecular gas acetylene and atomic vapour rubidium. The observation of electromagnetically induced transparency (EIT) in acetylene-filled HC-PCF represents the first such observation in a molecular gas, while the use of a photonic microcell allows a comparison of many experimental configurations to explore the coherence properties of coherent optical systems in the core of a HC-PCF. Furthermore, EIT is observed unambiguously in a rubidium loaded HC-PCF for the first time, and the anti-relaxation effects of a polymer coating demonstrated in this configuration.

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Clark, Paul. "Quantum optics of electrons in graphene". Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/416896/.

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The unique properties of graphene's band structure can lead to negative refraction of charge carriers incident on PN junctions. When coupled with an angular dependent transmission probability this can be utilised to form a novel split path interferometer. Many practical challenges are present and novel methods of fabrication are required to realise such a device. A large mean free path is required in order to achieve ballistic transport; a fundamental requirement of such a lensing device. Graphene on a hexagonal boron nitride (hBN) substrate is used in order to remove as many scattering sites as possible to enable the devices to be modelled using ballistic transport. Bubbles between graphene and boron nitride flakes are found and a method for their removal explained. Equipment was modified to allow the use of the latest graphene flake dry transfer methods, which enable the fabrication of hBN-graphene-hBN sandwich devices with one dimensional edge contacts. Multiple device designs are proposed which would exhibit interesting physics and give evidence for negative refraction in graphene and for the angular transmission probability of Klein tunnelling. The possibility of using He ion carving to produce a very small quantum point contact was explored and a nanoribbon with a width of 8 nm was fabricated and measured.

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Oser, Dorian. "Integrated silicon photonics for quantum optics". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS455.

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La photonique silicium est un domaine prolifique de l’optique intégrée. Elle permet de miniaturiser de nombreuses fonctionnalités optiques, l’émission laser (en considérant les stratégies d’intégration hybride), la modulation électro-optique, le routage, la détection, pour les télécoms, les LIDAR ou la spectroscopie, la métrologie, les capteurs et laboratoires sur puce, toute en produisant à grande échelle avec une grande précision et à bas coût (grâce au technologies CMOS de la microélectronique). L’optique quantique, quant à elle, souffre d’une grande sensibilité aux vibrations et à l’environnement. Les montages optiques nécessitent stabilité, alignement parfait et un grand nombre d’éléments optiques, ce qui limite son développement à grande échelle. Inversement, tous ces aspects sont naturels en photonique intégrée. Le développement de la photonique quantique est ainsi susceptible de permettre l’implémentation à large échelle de systèmes de clés de cryptage pour les télécoms et le calcul quantique. Les prérequis de la photonique quantique sont globalement plus sévères que ceux de la photonique classique. La génération d’états quantiques nécessite notamment un niveau de réjection de la pompe de plus de 100 dB ; le niveau de bruit photonique ambiant sur la puce est également un facteur à soigner particulièrement dans la mesure où les paires de photons générées par les processus quantiques sont par principe de très faible puissance. Dans ce contexte, cette thèse aborde le développement de composants et de circuits pour la photonique quantique silicium. Le but est de générer des états intriqués en énergie-temps et de pouvoir les manipuler sur une puce. Cela va de la conception à l’utilisation des paires de photons, en passant par la fabrication des circuits intégrés optiques. La qualification des propriétés quantiques est aussi explorée afin de cerner les limitations de la plateforme silicium pour le domaine applicatif visé. L’esprit de ce travail est également de proposer des solutions restantes compatibles avec les canaux de télécommunications standard (ITU), de n’utiliser que des composants fibrés standards pour les connexions à réaliser, tout en restant compatibles avec les techniques de fabrication industrielle des grandes fonderies microélectroniques afin de permettre une future production à grand échelle des circuits photoniques quantiques
Silicon photonics is a dynamic research field of integrated optics. It allows to miniaturize numerous optical functionalities such as lasers, electro-optical modulators, routers, detectors, for telecom wavelengths, LIDAR, sensor, metrology or even spectroscopy, all while been able to propose large scale production high precision technologies. On another side, quantum optics suffers from difficulties to scale optical systems, requires extreme stability, perfect alignment, and many bulky optical elements, while solving these issues follows a natural path in integrated photonics. Development of integrated quantum photonics can thus open the door to cheap, powerful, and scalable systems for quantum cryptography, telecoms, and computation. In a significant way, quantum requirements are not the ones of classical circuits with respect to photonic components and circuits. The generation of quantum states indeed requires more than 100dB of pump laser rejection, while being able to manage ultra-low useful optical signals and get rid of on-chip optical noise. In this context, this thesis is dedicated to the study, dimension, realization, and characterization of silicon photonic components and circuits for quantum optics on a chip. The target goal is to generate entangled states in energy-time and manipulate them on chip. The qualification of the quantum properties is also explored to better understand the limitations of the silicon platform in the followed objectives. Another choice of this work is to stay in telecoms wavelength and aligned with the standard channels (ITU grid), to only use off-the-shelf components, all while been CMOS compatible and compliant with standard fabrication process, this to allow the possibility to produce on large scale

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Dhayal, Suman. "Nonlinear and Quantum Optics Near Nanoparticles". Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc822820/.

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We study the behavior of electric fields in and around dielectric and metal nanoparticles, and prepare the ground for their applications to a variety of systems viz. photovoltaics, imaging and detection techniques, and molecular spectroscopy. We exploit the property of nanoparticles being able to focus the radiation field into small regions and study some of the interesting nonlinear, and quantum coherence and interference phenomena near them. The traditional approach to study the nonlinear light-matter interactions involves the use of the slowly varying amplitude approximation (SVAA) as it simplifies the theoretical analysis. However, SVVA cannot be used for systems which are of the order of the wavelength of the light. We use the exact solutions of the Maxwell's equations to obtain the fields created due to metal and dielectric nanoparticles, and study nonlinear and quantum optical phenomena near these nanoparticles. We begin with the theoretical description of the electromagnetic fields created due to the nonlinear wavemixing process, namely, second-order nonlinearity in an nonlinear sphere. The phase-matching condition has been revisited in such particles and we found that it is not satisfied in the sphere. We have suggested a way to obtain optimal conditions for any type and size of material medium. We have also studied the modifications of the electromagnetic fields in a collection of nanoparticles due to strong near field nonlinear interactions using the generalized Mie theory for the case of many particles applicable in photovoltaics (PV). We also consider quantum coherence phenomena such as modification of dark states, stimulated Raman adiabatic passage (STIRAP), optical pumping in $4$-level atoms near nanoparticles by using rotating wave approximation to describe the Hamiltonian of the atomic system. We also considered the behavior of atomic and the averaged atomic polarization in $7$-level atoms near nanoparticles. This could be used as a prototype to study any $n-$level atomic system experimentally in the presence of ensembles of quantum emitters. In the last chapter, we suggested a variant of a pulse-shaping technique applicable in stimulated Raman spectroscopy (SRS) for detection of atoms and molecules in multiscattering media. We used discrete-dipole approximation to obtain the fields created by the nanoparticles.

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Oskay, Windell Haven. "Atom optics experiments in quantum chaos". Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3040634.

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Antonio, Pontin. "Stabilized optomechanical systems for Quantum Optics". Doctoral thesis, Università degli studi di Trento, 2014. https://hdl.handle.net/11572/367926.

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The optomechanics field of research has been gathering a lot of momentum during the last couple of years. Recent experimental results show that the field is finally entering the quantum era. In this context, we have worked to develop new and competitive optomechanical devices. We have also worked towards the generation and observation of ponderomotive squeezing and we have identified, and experimentally demonstrated, an optomechanical effect that can ease the achievement of this goal. Finally, we have developed a stabilization technique that have been instrumental for the success of two experiments: the implementation of the Wiener-Kolmogorov data analysis and the squeezing of a mechanical thermal oscillator.

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Antonio, Pontin. "Stabilized optomechanical systems for Quantum Optics". Doctoral thesis, University of Trento, 2014. http://eprints-phd.biblio.unitn.it/1166/1/PhD_Thesis_-_A_Pontin.pdf.

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The optomechanics field of research has been gathering a lot of momentum during the last couple of years. Recent experimental results show that the field is finally entering the quantum era. In this context, we have worked to develop new and competitive optomechanical devices. We have also worked towards the generation and observation of ponderomotive squeezing and we have identified, and experimentally demonstrated, an optomechanical effect that can ease the achievement of this goal. Finally, we have developed a stabilization technique that have been instrumental for the success of two experiments: the implementation of the Wiener-Kolmogorov data analysis and the squeezing of a mechanical thermal oscillator.

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Hinzer, Karin. "Optical properties of gallium arsenide-based self-assembled quantum dots and quantum dot lasers". Thesis, University of Ottawa (Canada), 2002. http://hdl.handle.net/10393/6055.

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Three-dimensional confinement of carriers eliminates the problem of thermal spreading of carriers observed in higher-dimensional systems. Uniform self-assembled quantum dots (QDs) are obtained using the spontaneous islanding of highly strained III-V semiconductors grown with standard epitaxy. Visible stimulated emission has been obtained with red-emitting AlInAs QDs in AlGaAs barriers. Continuous (CW) threshold current densities below 100A/cm2 have been measured at low temperatures and QD material gain larger than 1.7 x 104 cm-1 demonstrate good material quality. Room temperature lasing has also been observed for higher threshold current densities. For longer wavelengths where the thermionic emission problem is less important, InAs/GaAs lasers can operate at room temperature for current densities below ∼100A/cm2 for wavelengths around 950 nm. The zero-dimensional transitions between confined electrons and holes in artificial atoms allow the observation of state-filling at relatively low level of material excitation. Lasing is observed in the upper QD shells for small gain media, and progress towards the QD ground states for longer cavity lengths. Gain may also be increased by including multiple layers of QDs in the active region. To understand the shell structure of AlInAs/AlGaAs QDs, we present results of interband spectroscopy of single Al0.36In0.64As/Al 0.33Ga0.67As self-assembled QDs. The single dot spectroscopy has been carried out at low temperature as a function of the excitation power and magnetic field up to 8 T. The emission spectra as a function of excitation power show two distinct groups of transitions which we associate with the recombination from ground and excited QD levels with a spacing of ∼70 meV. The application of magnetic field allows to identify the exciton emission as well as the emission from the bi-exciton, and charged exciton complexes with binding energies of ∼5 meV. The binding energies compare favorably with results of calculations. Artificial molecules are studied using coupled QD ensembles and single QD spectroscopy. The coupling between the zero-dimensional states is varied by changing the distance between two layers of stacked InAs/GaAs QDs. Energy level splitting larger than 30 meV of the symmetric and anti-symmetric states of the lowest confined shell are measured and are compared to theory.

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Kelly, Stephen C. "EXPLORATION OF QUBIT ASSISTED CAVITY OPTOMECHANICS". Miami University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=miami1408097717.

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Cui, Guoqiang. "An external optical micro-cavity strongly coupled to optical centers for efficient single-photon sources". Thesis, Connect to title online (ProQuest), 2008. http://proquest.umi.com/pqdweb?did=1525705811&sid=1&Fmt=2&clientId=11238&RQT=309&VName=PQD.

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Thesis (Ph. D.)--University of Oregon, 2008.
Typescript. Includes vita and abstract. Includes bibliographical references (leaves 147-163). Also available online in ProQuest, free to University of Oregon users.

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Smith, Roger. "The Double-Heralded Generation and Frequency Translation of Two-Photon States of Light in Optical Fibers". Thesis, University of Oregon, 2016. http://hdl.handle.net/1794/20696.

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The creation of optical states of light that are quantum mechanical in nature in optical fibers is discussed and demonstrated experimentally. Specifically, two- photon states created by spontaneous four-wave-mixing in commercially available single-mode, birefringent fibers are studied. When creating photon states of light, it is important to verify the created states are of the proper photon number distribution and free of noise. We detail a method for combining thresholding, non-number resolving detectors to characterize the photon number distribution created via SFWM and a procedure to quantify the noise sources present in the process. Frequency translation in optical fibers with two-photon states is discussed and experimental considerations are presented.

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Bochinski, Jason Russell. "Experimental studies of optical amplification and absorption by two-level atoms under strong, bichromatic field excitation /". view abstract or download file of text, 2000. http://wwwlib.umi.com/cr/uoregon/fullcit?p9998026.

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Thesis (Ph. D.)--University of Oregon, 2000.
Typescript. Includes vita and abstract. Includes bibliographical references (leaves 184-201). Also available for download via the World Wide Web; free to University of Oregon users. Address: http://wwwlib.umi.com/cr/uoregon/fullcit?p9998026.

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Gouraud, Baptiste. "Optical nanofibers interfacing cold toms. A tool for quantum optics". Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066026/document.

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Cette thèse a consisté à mettre en place une nouvelle expérience utilisant des atomes froids en interaction avec la lumière guidée par une nanofibre optique. Nous avons tout d'abord développé un banc de fabrication de nanofibres. En chauffant et étirant une fibre optique commerciale, on obtient un cylindre de silice de 400 nm de diamètre. La lumière guidée dans ces nanofibres est fortement focalisée sur toute la longueur de la fibre et exhibe de forts champs évanescents, ce qui permet d'obtenir une grande profondeur optique avec un faible nombre d'atomes. Après avoir inséré une nanofibre au milieu d'un nuage d'atomes, nous avons observé le phénomène de lumière lente dans les conditions de transparence électromagnétiquement induite. Nous avons aussi stoppé la lumière guidée et mémorisé l'information qu'elle contenait. Nous avons montré que ce protocole de mémoire optique fonctionne pour des impulsions lumineuses contenant moins d'un photon en moyenne. Ce système pourra donc être utilisé comme une mémoire quantique, un outil essentiel pour les futurs réseaux de communication quantique. Enfin, nous avons piégé les atomes dans un réseau optique au voisinage de la nanofibre grâce à de la lumière guidée par celle-ci. Par rapport à notre première série d'expériences, le nuage ainsi obtenu a un temps de vie plus long (25 ms) et interagit plus fortement avec la lumière guidée (OD ~ 100). Ce nouveau système devrait permettre d'implémenter efficacement d'autres protocoles d'optique quantique, comme la génération de photons uniques et l'intrication de deux ensembles atomiques distants
We built a new experiment using cold atoms interacting with the light guided by an optical nanofiber. We first developed a nanofiber manufacturing bench. By heating and stretching a commercial optical fiber, a silica cylinder of 400 nm diameter is obtained. The light guided in these nanofibers is strongly focused over the whole length and exhibits strong evanescent fields. We then prepared a vacuum chamber and the laser system necessary for the manipulation of cold atoms. After inserting a nanofiber amid a cloud of cold atoms, we observed the phenomenon of slow light under the conditions of electromagnetically induced transparency: the light guided by the fiber is slowed down to a speed 3000 times smaller than its usual speed. We also stored the light guided by an optical fiber. After several microseconds, the information stored as a collective atomic excitation could be retrieved in the fiber. We have shown that this optical memory works for light pulses containing less than one photon on average. This system may therefore be used as a quantum memory, an essential tool for future quantum communication networks. Finally, we trapped atoms in an array in the vicinity of the nanofiber thanks to the light guided by the latter. Compared to our first set of experiments, the resulting cloud has a longer lifetime (25 ms) and interacts more strongly with the guided light (OD ~ 100). This new system should allow to efficiently implement other quantum optics protocols, such as the generation of single photons, or the entanglement of two remote atomic ensembles

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45

McAlister, Daniel Frank. "Measuring the classical and quantum states and ultrafast correlations of optical fields /". view abstract or download file of text, 1999. http://wwwlib.umi.com/cr/uoregon/fullcit?p9948024.

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Thesis (Ph. D.)--University of Oregon, 1999.
Typescript. Includes vita and abstract. Includes bibliographical references (leaves 197-201). Also available for download via the World Wide Web; free to University of Oregon users. Address: http://wwwlib.umi.com/cr/uoregon/fullcit?p9948024.

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46

McGuinness, Hayden James 1980. "The creation and frequency translation of single-photon states of light in optical fiber". Thesis, University of Oregon, 2011. http://hdl.handle.net/1794/11259.

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xiii, 164 p. : ill. (some col.)
We explore the frequency translation of single-photon states of light and the creation of photon pairs by four-wave mixing in optical fiber. Frequency translation refers to changing the central frequency of a field, while photon pair creation refers to the creation of two individual photons at the same time. We demonstrate these effects in third-order nonlinear optical fiber. While both phenomena have previously been shown by three-wave mixing in second-order nonlinear media, there are compelling reasons to develop these tasks in third-order media. Most importantly, frequency translation in third-order material allows for the practical implementation of both small and large frequency shifts, while second-order material only practically allows for large shifts. Photon creation in third-order media often permits more flexible phase-matching conditions, allowing for the creation of a wider variety of quantum states than is often possible in second-order media. In our theoretical study of photon pair creation, we focus on the spectral correlations of the photon pairs. We pay particular attention to the creation of quantum states of high purity, where the photons are not spectrally correlated with one another. High purity photons are a requisite resource for several different quantum information processing applications, such as linear-optical quantum computing. We find that states with high purity can be realized with a minimal amount of spectral filtering. Experimentally, we study photon frequency translation in photonic crystal fiber. The central wavelength of the input photons was translated from 683 nm to 659 nm. We perform second-order intensity correlation measurements on both channels to demonstrate their quantum nature. This resulted in values of 0.21 ± 0.02 and 0.19 ± 0.05 for the 683-nm and 659-nm channels, respectively, demonstrating that those fields were dominated by their single-photon component. The efficiency at which the process occurred was 29 percent. Theoretically, we develop a Green function formalism to describe the translation process and develop a computational model to calculate the solution to the governing equations. Also, in a related experiment, we demonstrate classical frequency translation from 851 nm to 641 nm, a record translation in both wavelength and frequency, at an efficiency of 0.2 percent in a birefringent fiber.
Committee in charge: Dr. Daniel Steck, Chair; Dr. Michael Raymer, Advisor; Dr. Steven van Enk, Inside Member; Dr. Raghuveer Parthasarathy, Inside Member; Dr. Andrew Marcus, Outside Member

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Dorier, Vincent. "Quantum theory of light in linear media : applications to quantum optics and quantum plasmonics". Thesis, Bourgogne Franche-Comté, 2020. http://www.theses.fr/2020UBFCK006.

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Nous développons une méthode de quantification du champ électromagnétique en interaction linéaire avec les milieux passifs d'une part, et les milieux actifs (plasmoniques) d'autre part. Cette méthode repose sur la construction d'une structure Hamiltonienne compatible avec les équations de Maxwell, puis sur un principe de correspondence et la définition d'un espace de Fock des états quantiques. Nous utilisons les résultats de la théorie quantique pour étudier la propagation de photons dans des environnements diéléctriques et l'émission de plasmons uniques
We develop a method of quantization of the electromagnetic field interacting with passive media on one hand, and active (plasmonic) media on the other hand. This method relies on the construction of a Hamiltonian structure compatible with the Maxwell equations, and then on a principle of correspondence and the definition of a Fock space of quantum states. We use the results of the quantum theory to study the propagation of photons in dielectric environments and the emission of single plasmons

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McDermott, Roger. "A quantum group approach to some exotic states in quantum optics". Thesis, Open University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261140.

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Elouard, Cyril. "Thermodynamics of quantum open systems : applications in quantum optics and optomechanics". Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY046/document.

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La thermodynamique a été développée au XIXe siècle pour décrire la physique des moteurs et autres machines thermiques macroscopiques. Depuis lors, le progrès des nanotechnologies a rendu nécessaire d'étendre ces lois, initialement pensées pour des systèmes classiques, aux systèmes obéissant à la mécanique quantique. Durant cette thèse, j'ai mis en place un formalisme pour étudier la thermodynamique stochastique des systèmes quantiques, dans lequel la mesure quantique occupe une place centrale: à l'instar du bain thermique de la thermodynamique statistique classique, la mesure est ici la source première d'aléatoire dans la dynamique. Dans un premier temps, j'ai étudié la mesure projective comme une transformation thermodynamique à part entière. J'ai montré que la mesure cause un changement incontrôlé de l'énergie du système quantique étudié, que j'ai appelé chaleur quantique, ainsi qu'une production d'entropie. Comme application de ces concepts, j'ai proposé un moteur qui extrait du travail à partir des fluctuations quantiques induites par la mesure. Ensuite, j'ai étudié les mesures généralisées, ce qui a permis de décrire des systèmes quantiques ouverts. J'ai défini les notions de travail, de chaleur, et de production d'entropie pour une réalisation unique d'une transformation thermodynamique, et retrouvé que ces quantités obéissent à des théorèmes de fluctuation. Ce formalisme m'a permis d'analyser le comportement thermodynamique de la situation canonique de l'optique quantique : un atome à deux niveaux en couplé à un laser et au vide électromagnétique. Enfin, j'ai étudié une plate-forme prometteuse pour tester la thermodynamique d'un Qubit : un système hybride optomécanique.Le formalisme développé dans cette thèse peut être d'un grand intérêt pour la communauté de thermodynamique quantique car il permet de caractériser les performances des machines thermiques quantiques et de les comparer à leurs analogues classiques. En outre, en caractérisant la mesure quantique comme un processus thermodynamique, il ouvre la voie à de nouveaux types de machines thermiques, exploitant d'une manière inédite les spécificités du monde quantique
Thermodynamics was developed in the XIXth century to provide a physical description to engines and other macroscopic thermal machines. Since then, progress in nanotechnologies urged to extend these formalism, initially designed for classical systems, to the quantum world. During this thesis, I have built a formalism to study the stochastic thermodynamics of quantum systems, in which quantum measurement plays a central role : like the thermal reservoir of standard stochastic thermodynamics, it is the primary source of randomness in the system's dynamics. I first studied projective measurement as a thermodynamic process. I evidenced that measurement is responsible for an uncontroled variation of the system's energy that I called quantum heat, and also a production of entropy. As a proof of concept, I proposed an engine extracting work from the measurement-induced quantum fluctuations. Then, I extended this formalism to generalized measurements, which allowed to describe open quantum systems (i.e. in contact with reservoirs). I defined work, heat and entropy production for single realizations of thermodynamic protocols, and retrieved that these quantities obey fluctuation theorems. I applied this formalism to the canonical situation of quantum optics, i.e. a Qubit coupled to a laser and a the vacuum. Finally, I studied a promising platform to test Qubit's thermodynamics: a hybrid optomechanical system.The formalism developed in this thesis could be of interest for the quantum thermodynamics community as it enables to characterize quantum heat engines and compare their performances to their classical analogs. Furthermore, as it sets quantum measurement as a thermodynamic process, it pave the ways to a new kind of thermodynamic machines, exploiting the specificities of quantum realm in an unprecedented way

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50

Kaiser, Florian. "Photonic entanglement engineering for quantum information applications and fundamental quantum optics". Nice, 2012. https://tel.archives-ouvertes.fr/tel-00777002.

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Le but de cette thèse est de développer des sources d’intrication photonique pour étudier les réseaux de communication quantique et l’optique quantique fondamentale. Trois sources très performantes sont construites uniquement autour de composants standards de l’optique intégrée et des télécommunications optiques. La première source génère de l’intrication en polarisation via une séparation déterministe des paires de photons dans deux canaux adjacents des télécommunications. Cette source est donc naturellement adaptée à la cryptographie quantique dans les réseaux à multiplexage en longueurs d’ondes. La seconde source génère, pour la première fois, de l’intrication en time-bins croisés, autorisant l'implémentation de crypto-systèmes quantiques à base d’analyseurs passifs uniquement. La troisième source génère, avec une efficacité record, de l’intrication en polarisation via un convertisseur d’observable temps/polarisation. La bande spectrale des photons peut être choisie sur plus de cinq ordres de grandeur (25 MHz - 4 THz), rendant la source compatible avec toute une variété d’applications avancées, telles que la cryptographie, les relais et les mémoires quantiques. Par ailleurs, cette source est utilisée pour revisiter la notion de Bohr sur la complémentarité des photons uniques en employant un interféromètre de Mach-Zehnder dont la lame séparatrice de sortie se trouve dans une superposition quantique d’être à la fois présente et absente. Enfin, pour adapter la longueur d’onde des paires des photons télécoms intriqués vers les longueurs d’ondes d’absorption des mémoires quantiques actuelles, un convertisseur cohérent de longueur d’onde est présenté et discuté
The aim of this thesis is to develop sources of photonic entanglement to study both quantum networking tasks and some of the foundations of quantum physics. To this end, three high-performance sources are developed, each of them taking extensively advantage of standard telecom fibre optics components. The first source generates polarization entanglement via deterministic pair separation in two adjacent telecommunication channels. This source is naturally suitable for quantum cryptography in wavelength multiplexed network structures. The second source generates for the first time a cross time-bin entangled bi-photon state which allows for quantum key distribution tasks using only passive analyzers. The third source generates, with a record efficiency, polarization entanglement using an energy-time to polarization entanglement transcriber. The photon spectral bandwidth can be chosen over more than five orders of magnitude (25 MHz - 4 THz). This permits implementing the source into existing telecom networks, but also in advanced quantum relay and quantum memory applications. Moreover, this source is used to revisit Bohr’s single-photon wave-particle complementarity notion via employing a Mach-Zehnder interferometer with an output quantum beam-splitter in a true superposition of being present and absent. Finally, to adapt the wavelength of the entangled telecom photon pairs to the absorption wavelength of current quantum memories, a coherent wavelength converter is presented and discussed

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