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Ouadjou, Abdesselam. "Effets electrooptiques non linéaires dans les liquides diélectriques. Inclusion de l'inertie". Perpignan, 1994. http://www.theses.fr/1994PERP0172.
Pełny tekst źródłaMacon, Louis. "Effets polarimétriques en régimes linéaires et non linéaire dans les fibres optiques uni modales biréfringentes". Nice, 1986. http://www.theses.fr/1986NICE4031.
Pełny tekst źródłaBonnefois, Jean-Jacques. "Modélisation d'effets non linéaires dans les cristaux photoniques, application à la limitation optique". Paris 10, 2006. http://www.theses.fr/2006PA100131.
Pełny tekst źródłaWe present here a discussion about the use of optical nonlinear material in photonic crystals (PCs) for optical limiting purpose. The link between cubic (Kerr) nonlinearities or phase transition and the complex diffraction phenomenon occurring inside a PC can allow ultra-frit and self-triggered switching from a transparent state towards an opaque one. To study this, we developed new ab-initio numeric methods evolved from the Fast Fourier Factorization (FFF) and the Matrix Scattering Method (MSM). Those methods allow the rigorous simulation of nonlinear inhomogeneous inclusion and the thermal behaviour of a CP while illuminated by a nanosecond laser pulse. In the last part of this document, the precision of the "homogeneous approximation" will be discussed and partially questioned. Finally, a CP based optical limiter solution is proposed
Burger, Sylvain. "Synthèse et étude des propriétés optiques non-linéaires d'ordre trois de nouvelles molécules push-pull à transmetteur hétérocyclique hexagonal ou pentagonal". Besançon, 2001. http://www.theses.fr/2001BESA2025.
Pełny tekst źródłaRaineri, Fabrice. "Optique non linéaire dans les cristaux photoniques en semiconducteur III-V". Paris 11, 2004. https://tel.archives-ouvertes.fr/tel-00009192.
Pełny tekst źródłaIt is believed that the future developments in optical networks will rely crucially on all-optical processing. The use of light as the information carrier instead of electrons provides higher data transmission rate across long distances, ina fast and a reliable way. Moreover, all-optical devices with their inherent potentiel to avoid detrimental thermal effects, allows a miniaturization down to the nanoscale. In the search for such all optical devices, photonic crystals are increasingly evoked. These periodic structures with their lattice dimension of the order of the light wavelength constitutes an innovative way to control the electromagnetic field propagation over one, two or the three directions of the space. It has been shown that it is possible to design integrated optical devices using these structures such as filters, routers, etc. , for all optical signal processing. By controlling the opto-geometrical parameters of these structures, it is possible to slow down the light, to localize it and to control ots phase and group velocities. This can lead to a strong enhanement of the nonlinear interactions. Conversely, nonlinear optics brings to photonic crystals new functionalities such as frequency conversion, switching, amplification, etc. In this thesis, we report on the design and the fabrication of 1D and 2D photonic crystals in AlGaAs optimized to obtain efficient second harmonic generation within short distance. We also show that the important non linearities of III-V semiconductors can be avantageously used in 2D photonic crystals to obtain laser effet, tunability, ultrafast switching and amplification
Jenneve, Philippe. "Analyse Expérimentale des Distorsions Non-Linéaires pour la Construction d’un Estimateur de Performances des Réseaux Optiques Cohérents". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLO014.
Pełny tekst źródłaNowadays, high-speed fiber-optic communication networks are the basis of information technology and the subject of intense research. Innovation enables transponders to be flexible and versatile, but fiber optical networks are still configured manually and especially almost never tuned during the life of the network. One of the blocking points toward reconfigurable and automated optical networks is the need of performance prediction for any link of the network in an accurate and fast way. However, the prediction is made even more complex by the diversity of deployed optical fiber types and propagation regimes.During my work, I addressed experimentally the signal distortions coming from nonlinear Kerr effects accumulated on hundreds of kilometers of optical fibers. Based on specific and controlled experiments, I have measured and highlighted the properties of the nonlinear distortions. These analyses allowed me to design a performance model estimator that can be applied to heterogeneous optical links with various optical fiber types and propagation regimes.The flexibility of transponders associated with a performance estimator will optimize and tune the channels dynamically depending on the load and the topology of the network, as well as compute the protection and restoration links
Lefort, Laurent. "Opérations phoniques rapides basées : sur l'intéraction de solitons spatiaux : sur des processus non-linéaires quadratiques". Limoges, 1996. http://www.theses.fr/1996LIMO0040.
Pełny tekst źródłaDherbecourt, Jean-Baptiste. "Processus non linéaires pour la génération d'impulsions picosecondes accordables dans l'infrarouge moyen". Phd thesis, Palaiseau, Ecole polytechnique, 2011. http://pastel.archives-ouvertes.fr/docs/00/59/92/11/PDF/JBthese.pdf.
Pełny tekst źródłaMany applications, like time-resolved spectroscopy, require the development of new coherent light sources emitting tunable short pulses in the mid-infrared. In this field, nonlinear optics offer particularly attractive solutions. First of all, the parametric generation process allows extension of the spectral coverage of conventionnal laser sources. Secondly, nonlinear processes display specific properties, which can be controlled in order to create original fast optical functions. In this work, we use these properties to realize picosecond pulses generation devices. We begin with the realization of a synchronously pumped OPO based on a ZGP crystal, emitting tunable picosecond pulses in the 3,8 µm- 5,6 µm spectral range. The performances of the different conversion stages are discussed from experimental and numerical considerations. Then we adress optical sources including a laser medium and a nonlinear crystal. We build a nonlinear mirror using a PPLN crystal and insert it in a Cr2+:ZnSe laser to produce tunable picosecond pulses by passive modelocking in the 2,45 µm - 2,55 µm range. The nonlinear mirror is designed and characterized in an extracavity experiment, then we detail the mode-locking experiment. Finally, we generalize the nonlinear mirror concept, by proposing means of getting passive mode-locking by combination of amplitude and phase modulation in the laser cavity
Coda, Virginie. "Solitons optiques spatiaux kerr et photoréfractifs : propriétés fondamentales et application à l'adressage optique". Besançon, 2006. http://www.theses.fr/2006BESA2065.
Pełny tekst źródłaDuchesne, Claire. "Etude des propriétés optiques non linéaires dans les verres : cas du système Na₂O-TiO₂-P₂O₅". Bordeaux 1, 1993. http://www.theses.fr/1993BOR10614.
Pełny tekst źródłaShalaby, Badr Mohamed Ibrahim. "Expériences d'interaction entre faisceaux autoguides "solitons" : nouvelles opérations de photonique picoseconde". Limoges, 1993. http://www.theses.fr/1993LIMO0204.
Pełny tekst źródłaOlmedo, Herrero Elena. "Étude des effets non linéaires dans les lasers et amplificateurs de puissance à fibre double gaine dopée Er3+/Yb3+". Phd thesis, Télécom ParisTech, 2003. http://pastel.archives-ouvertes.fr/pastel-00000743.
Pełny tekst źródłaBoucher, Vincent. "Solitons spaciaux : contribution à l'étude de propagation non linéaire". Angers, 2001. http://www.theses.fr/2001ANGE0018.
Pełny tekst źródłaMessaad, Khalida. "Contribution à la conception de guides optiques à fortes susceptibilités non-linéaires d'ordre 3". Phd thesis, Université Rennes 1, 2009. http://tel.archives-ouvertes.fr/tel-00456183.
Pełny tekst źródłaDoutte, Anne. "Étude expérimentale et théorique de la dynamique des lasers Raman à fibre optique". Lille 1, 2005. http://www.theses.fr/2005LIL10158.
Pełny tekst źródłaCornet, Marion. "Développement de sources térahertz intenses et applications en optique non-linéaire". Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0194/document.
Pełny tekst źródłaThis thesis project aims to study different non-linear processes in zinc-blende crystals,which take place in the terahertz (THz) range.First of all, two different light sources have been built in the laboratory, allowing us togenerate intense THz radiations with different temporal and spectral characteristics. Thefirst source is based on the optical rectification of a femtosecond laser pulse in a lithiumniobate crystal using the tilted pulse front technique, while the second one is based on aplasma, created through the focalization of a two-color femtosecond laser field. These twoTHz sources reach very high amplitudes, which allows us to study non-linear phenomenain the THz range.Among these, we have measured the non-linear behavior of zinc-blende crystals underintense THz radiation. We were particularly interested in the Pockels effect happeningduring the interaction of an intense THz field and a weak optical probe beam. This droveus to the experimental and numerical demonstration of a new method to characterize thespectral phase of the optical probe field. This method is equivalent to the X-FROG technique.We also identified a new non-linear phenomenon, consisting of the cascade of twosecond-order processes, namely the Pockels effect and the Second Harmonic Generation.Finally, we experimentally observed some THz Kerr effect in a gallium phosphide crystal,which allowed us to calculate an average value of its third-order non-linear susceptibility,thanks to theoretical considerations and simulations
Boughdad, Omar. "Fluides de lumière dans un milieu non-linéaire photoréfractif". Thesis, Université Côte d'Azur, 2020. http://www.theses.fr/2020COAZ4014.
Pełny tekst źródłaThis thesis presents an experimental study of hydrodynamical phenomena of a laser propagating nonlinearly. For a medium presenting an intensity-dependent refractive index, and in the frame of the paraxial approximation, The intensity of the laser beam is equivalent to a density of a fluid, the propagation direction is seen as a time evolution of the fluid as well as the phase gradient of the laser beam defines a flow velocity and the nonlinear refractive index change allows defining a sound velocity of the fluid. Under this analogy, we call the propagating laser beam a fluid of light. In this thesis, we provide a study of the superfluidity concept of a fluid of light in a selfdefocusing regime of the nonlinearity. It is defined as the absence of diffraction when the fluid of light encounters an obstacle. The parameters which control the superfluid transition are: the flow velocity as well as the sound velocity. They are controlled respectively through the wave vector and the intensity of the laser beam. In the frame of this analogy, we also present in this thesis a study of vortex shedding regime as a result of the interaction between the fluid of light and the obstacle. Here, the obstacle is considered to be strong. When twice the flow velocity at the poles of the obstacle is larger than the sound velocity, pairs of vortex/anti-vortex are emitted demonstrating a hydrodynamical behaviour of the fluid of light. In order to underline the nonlinear refractive index change, we also report in this thesis a study of the photorefractive effect using the self-phase modulation effect
Cortès, Pierre-Yves. "Compensation de la dispersion chromatique et des effets non-linéaires par conjugaison de phase optique pour les systèmes de télécommunications par fibre à haut débit". Limoges, 1996. http://www.theses.fr/1996LIMO0036.
Pełny tekst źródłaBergmann, Emeric. "Optique non linéaire quadratique et cubique des nanoparticules d'or uniques". Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10291/document.
Pełny tekst źródłaThe manuscript reports a study about the quadratic and cubic nonlinear optical response from gold metallic nanostructures which are deposited onto substrates. The field of this work is more commonly known as nonlinear plasmonics and it consists in trying to understand the interaction between nanostructures and light, in a regime of high incident intensities when the response is no longer linear. The local electromagnetic field enhancement in these structures due to the surface plasmon resonance, the latters being collectives excitations of the conduction band electrons, increase drastically the cross-section for these processes. In the context of a quadratic response, the study has been focused on the Second Harmonic Generation (SHG) process whereby two incident photons at the fundamental wavelength are converted into one photon at twice the harmonic frequency. This process is highly dependent to the metallic nanostructures morphology. For the cubic response, the study has been focused on the optical Kerr effect which describes the optical index variation of nanostructure with the intensity of the incident wave.Specifics considerations have been taken into account about the geometrical illumination conditions which are performed with a large numerical aperture. The electromagnetic incident field cannot be anymore considered within the paraxial approximation
Lefkir, Miloud. "Mesure des susceptibilités non linéaires d'ordre trois par auto-modification de l'état de polarisation d'une onde lumineuse : rôle des gradients transversés du champ". Angers, 1996. http://www.theses.fr/1996ANGE0025.
Pełny tekst źródłaRigneault, Hervé. "Perturbations photo-induites dans les couches minces diélectriques soumises à un flux laser de puissance". Aix-Marseille 3, 1993. http://www.theses.fr/1993AIX30074.
Pełny tekst źródłaLabidi, Tarek. "Amplification sensible à la phase de signaux analogiques sur porteuse optique". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS340/document.
Pełny tekst źródłaMicrowave photonic links are expected to play an important role in future RF systems. Based on low loss optical fibers, analog photonic links (APLs) have become the heart of the emerging field of microwave photonics, in which various functionalities are explored such as the generation and distribution of radar signals and local oscillators, phase shifting, reconfigurable true time delays, or even more complex functions such as spectrum analysis or correlation of RF signals. Unavoidably, microwave photonics systems undergo losses due either to microwave-to-optical conversion or to propagation. Classical amplifiers based on erbium doped fibers, semiconductor amplification, or Raman scattering in fibers, do not allow to compensate for these losses without degrading the signal-to-noise ratio. The aim of this thesis is to address this issue and to theoretically study and experimentally an optical phase-sensitive amplifier based on highly nonlinear fiber (HNLF) in order to amplify an analog signals without adding noise. We experimentally investigate the linearity of a phase sensitive amplifier based on nonlinear optical fiber in the context of microwave photonics. The linearity of the PSA amplifier is assessed by performing third order intermodulation distortion products (IMD3) measurements using two RF tones. The results show that the PSA is, in the explored domain, perfectly linear for the RF modulation, leading to amplification without any increase of distortion, thus proving the compatibility with future microwave photonics applications. In addition, we study the performance of our PSA in terms of noise by taking measurements of the noise figure (NF). Indeed, we measure a noise factor of -2.07 dB in the case where when we detect only the signal, while a 0.2 dB noise factor is obtained when both "signal and idler" are detected
Tang, Xuefeng. "Optical phase conjugation and its application in the compensation of fiber Kerr nonlinearities". Lorient, 2005. http://www.theses.fr/2005LORIS052.
Pełny tekst źródłaWith the increase of the bit rate and channel number in optical fiber communications, the fiber nonlinearity, especially the Kerr nonlinearity, has been reconsidered as one of the most important limitations on the transmission performance. As an important nonlinear optical technique, optical phase conjugation (OPC), has been paid increasing attention due to its ability to compensate for the dispersion and the nonlinear effects in fiber transmissions. In this dissertation, we investigate the compensation process of nonlinear effects, including self-phase modulation (SPM), cross-phase modulation (XPM), intrachannel nonlinear interaction and nonlinear noise amplification in OPC systems, using theoretical analysis and numerical simulations. It is shown that OPC has a very promising ability to compensate for the fiber nonlinearities, while its performance is affected by some factors such as the signal evolution symmetry, the dispersion regime and the fiber-link configuration. With the optimization of the dispersion map design (fiber-link configuration), the compensation performance of OPC can be improved considerably, which shows a very attractive implementation in either time division multiplexing (TDM) or wavelength division multiplexing (WDM) schemes. In addition, we have made a contribution to the study of the temperature tuning effect on the quasi-phase-matching (QPM) difference-frequency-generation (DFG), and a multi-segment temperature tuning method is proposed to optimize the QPM-DFG performance
Coda, V. "Solitons optiques spatiaux Kerr et photoreactifs : propriétés fondamentales et application à l'adressage optique". Phd thesis, Université de Franche-Comté, 2006. http://tel.archives-ouvertes.fr/tel-00373624.
Pełny tekst źródłaCoda, Virginie. "Solitons optiques spatiaux Kerr et photoréfractifs : propriétés fondamentales et application à l'adessage optique". Phd thesis, Université de Franche-Comté, 2006. http://tel.archives-ouvertes.fr/tel-00137257.
Pełny tekst źródłaLa première partie présente des résultats sur les solitons Kerr, aux longueurs d'onde des télécommunications, formés dans des guides plans basés sur le semiconducteur AlGaAs. Nous avons montré que les absorptions non linéaires, bien que faibles, influencent de manière déterminante l'autofocalisation des faisceaux. Par ailleurs, nous avons déterminé expérimentalement les durées d'impulsions compatibles avec la génération de
solitons. Une propagation solitonique a été obtenue sur une distance de 17 longueurs de diffraction.
Dans une seconde partie, nous avons étudié un nouveau type de soliton brillant bidimensionnel, le soliton photoréfractif-photovoltaïque avec champ appliqué dans le LiNbO3. Ce soliton est caractérisé par l'application d'un champ électrique qui s'oppose à l'effet photovoltaïque intrinsèque au matériau afin de produire un effet non linéaire focalisant. En accord avec le modèle semi-analytique et les simulations numériques développés, les expériences réalisées montrent que ces solitons constituent une technique simple pour générer des guides à symétrie circulaire, droits ou courbes, utilisables aux longueurs d'onde du visible mais également dans l'infrarouge.
Enfin, nous avons testé les potentialités des solitons
pour l'adressage optique à travers deux applications. La première a permis de vérifier les capacités des solitons Kerr dans AlGaAs pour des interconnexions rapidement reconfigurables. Dans une seconde configuration, un composant d'optique intégrée 3-D remplissant la fonction de routage 1 vers 4 a été réalisé dans le LiNbO3 à l'aide de solitons photoréfractifs.
Nguyen, Duc Minh. "Investigations et caractérisations de fibres et guides optiques très fortement non-linéaires". Phd thesis, Université Rennes 1, 2011. http://tel.archives-ouvertes.fr/tel-00663282.
Pełny tekst źródłaGodard, Pierre. "Optique électromagnétique non-linéaire polyharmonique : théorie et modélisation numérique". Phd thesis, Université de Provence - Aix-Marseille I, 2009. http://tel.archives-ouvertes.fr/tel-00439833.
Pełny tekst źródłaFahmi, Abdelilah. "Contrôle des effets non linéaires dans des liquides en mélange d'ondesApplication à la mesure de la susceptibilité non linéaire et à la conjugaison de phase". Angers, 1995. http://www.theses.fr/1995ANGE0022.
Pełny tekst źródłaNguyen, Duc Minh. "Investigations et caractérisations de fibres et guides optiques très fortement non-linéaires". Rennes 1, 2011. http://www.theses.fr/2011REN1E006.
Pełny tekst źródłaMalvache, Arnaud. "Optique non-linéaire à haute intensité : Compression d'impulsions laser Interaction laser-plasma". Phd thesis, Palaiseau, Ecole polytechnique, 2011. https://theses.hal.science/index.php?halsid=uofsba7dj5fa0catc3i9mh00v0&view_this_doc=pastel-00677295&version=1.
Pełny tekst źródłaThis mainly theoretical PhD thesis has been done in the framework of high-order harmonics generation on solid targets using 1mJ ultrashort laser pulses (2 optical cycles) at high repetition rate (1kHz), CEP-stabilized. On the one hand, in order to fully use the laser source, I developed a simulation code of hollow-core fiber propagation. The results of this code, associated with an experimental study, allowed to push the energy limitation of this compression technique. On the other hand, I used PIC simulation and I developed a simulation model of CWE in order to quantify its dependence to the laser and plasma parameters. This work first helped to explain the CWE spectrum changes with pulse CEP. Second, by comparing theoretical results with an experimental parametric study, it provided information about the plasma conditions such as density gradient and electronic temperature
Cassagne, Christophe. "Développement des procédés de mesure de déphasage optique : applications aux non linéarités induites par effet Kerr dans certaines molécules organiques". Thesis, Angers, 2018. http://www.theses.fr/2018ANGE0010/document.
Pełny tekst źródłaOur study concerns the measurement of the nonlinear (NL) optical phase shift of order three. Two categories of methods will be addressed: i) the phaseshift interferometric technique that allows phase characterization with good spatial resolution, which is crucial for a focused beam in the non-linear medium. This technique uses the least squares criterion associated with several interferograms. Implemented using a spatial light modulator, it provides a practical calibration for each phase shift considered. The reliability of the proposed method is verified by direct comparison with the Fourier transformation method; ii) innovative Z-scan methods combined with an imager assembly. They will be applied here to measurements of the NL coefficients of order three and higher. We will show that the flexibility of using a CCD camera allows for better pointing and real-time tracking of the beam. Finally, we will focus on the Dark-field Z-scan setup, which benefits from the advantages of high contrast dark field microscopy. These improvements potentially open up a new field of microscopic exploration for the investigation and mapping of non-linear effects
Bourassa, Jérôme. "Non-linéarité et couplages lumière-matière en électrodynamique quantique en circuit". Thèse, Université de Sherbrooke, 2012. http://hdl.handle.net/11143/6677.
Pełny tekst źródłaHache, François. "Effet Kerr optique dans les petites sphères et les colloïdes métalliques : étude théorique et expérimentale dans le cas de l'or". Paris 11, 1988. http://www.theses.fr/1988PA112169.
Pełny tekst źródłaBesse, Valentin. "Dynamique spatiale de la lumière et saturation de l’effet Kerr". Thesis, Angers, 2014. http://www.theses.fr/2014ANGE0030/document.
Pełny tekst źródłaWe present a study of light dynamics and measurements of the nonlinear optical characteristics of carbon disulphide. In the first part, we calculate using the classical model, the nonlinear susceptibilities up to the fifth order taking into account local field corrections. We express different assumptions that we confirm or refute by measuring the nonlinear absorption coefficient and the nonlinear refractive index. The measurements are performed by means of two nonlinear characterization methods combined with an imaging 4f system. We analyse the experimental data using a newly developed method which numerically inverts the analytical solutions of the differential equations which describe the evolution of the beam, using Newton’s method. In the second part, we observe light filamentation at wavelength 532 nm, in the picoseconds regime. Then we measure the effective third order nonlinear refractive index n2,eff versus the incident intensity. By fitting the curve of the Kerr effect saturation, we develop a new model. Numerically solving this model, allows us to reproducethe experimentally observed filamentation. The last part is dedicated to the study of dissipative solitons dynamics. The complex Ginzburg-Landau equation with cubic-quintic nonlineraties is numerically solved in various configurations : soliton fundamental dipole, quadrupole, vortex and square rhombic
Diallo, Souleymane. "Utilisation des non-linéarités Kerr et Brillouin dans les résonateurs à mode de galerie cristallins pour la synthèse de micro-ondes". Thesis, Besançon, 2016. http://www.theses.fr/2016BESA2028/document.
Pełny tekst źródłaWhispering galery mode resonators are dielectric cavities that support modes with ultra-high quality factor and small volume that remain confined in their inner periphery for time duratioons that can be as long as few microseconds. The strong confinement of these modes for such long durations strongly enhances nonlinear effect suchs as Kerr effect or Brillouin effect. These resonators can therefore be used for several applications such as spectroscopy, telecommunications or microwave generation. The objective of this thesis is to use Kerr and Brillouin nonlinearities in these resonators at the laser wavelength of 1550 nm, in order to generate high spectral purity microwave signals with frequencies rangong fros 5 to 30 GHz. The first chapter oh the thesis intriduces the theory, fabrication, coupling and characterisation of whispering gallery mode resonators. The second chapter is about the generation of Kerr optical frequency combs in these resonators and their application to the generation of microwave signals. We present our experimental resuktsdn the numerical modelling of Kerr combs, the analysis of oscillatory instabilities (due to thermal effect) observed during our experiments, and conclue. The third chapter concerns photon-phonon interactions via stimulated Brillouin scattering in these resonators and their application to the generation of microwave signals. We present our experimental results and the temporal model that we developed to track the dynamics of the forward and backscattered fields. The last chapter conclude the thesis. The research presented in this thesis has benne funded by the European Research Council through the project Nextphase
Malvache, Arnaud. "Optique non-linéaire à haute intensité : Compression d'impulsions laser Interaction laser-plasma". Phd thesis, Ecole Polytechnique X, 2011. http://pastel.archives-ouvertes.fr/pastel-00677295.
Pełny tekst źródłaCaumes, Jean Pascal. "Caractérisation de l'indice nonlinéaire induit en présence de génération de second harmonique ou de redressement optique : application à la compensation de l'intégrale de rupture". Bordeaux 1, 2002. http://www.theses.fr/2002BOR12606.
Pełny tekst źródłaLiu, Jingtian. "Shaping Strategies to Embrace Nonlinear Effects in Optical Fiber Communications". Electronic Thesis or Diss., Institut polytechnique de Paris, 2024. http://www.theses.fr/2024IPPAT007.
Pełny tekst źródłaThe main impediment in long-distance communications is nonlinear interference (NLI), stemming from nonlinear effects in optical fibers. While Digital signal processing algorithms offer partial mitigation, the inherent nonlinear nature of the fiber, coupled with predominant dispersion effects, continues to challenge the increase of transmission throughputs. Addressing nonlinearity at the information source through signal modulation technology is at the heart of our research. Traditional modulation schemes, as spectral efficiency climbs, such as QAM, become increasingly susceptible to NLI while their Mean Squared Euclidean Distance (MSED) diminishes. While multi-dimensional (MD) modulation yields improved linear and partial nonlinear gains, it has not yet demonstrated tangible benefits. On the other hand, the emergence of probabilistic constellation shaping (PCS), preferred for its enhanced linear gain and compatibility with conventional modulation hardware and software, introduces additional NLI. Consequently, the design of nonlinear-tolerant PCS is emerging as a pivotal research direction. Our thesis begins with a novel MD modulation for uniformly distributed signals. Then, we propose a novel approach combining MD with PCS to examine performance variations. Delving into PCS, we investigate the enumerative sphere shaping distribution matcher (DM), initially from an MD stance, and design a DM optimized for nonlinear tolerance over shorter distances. Subsequently, we introduce a new NLI measurement technique, accounting for dispersion effects. Integrating this with the sequence selection framework of PCS, we achieve successful long-distance transmission with notable nonlinear gains
Astic, Magali. "Exaltation des Non Linéarités du Troisième Ordre dans les Structures à Cristal Photonique". Phd thesis, Université Paris Sud - Paris XI, 2008. http://tel.archives-ouvertes.fr/tel-00579136.
Pełny tekst źródłaKasparian, Jérôme. "Propagation non-linéaire d'impulsions laser ultrabrèves dans l'atmosphère et applicationsDes filaments blancs pour sonder l'atmosphère". Habilitation à diriger des recherches, Université Claude Bernard - Lyon I, 2005. http://tel.archives-ouvertes.fr/tel-00011448.
Pełny tekst źródłaUne première catégorie d'applications, comme le Lidar à lumière blanche, repose sur l'exploitation du continuum de lumière blanche, par exemple pour réaliser une télédétection multi-composants dans l'air. Une seconde famille repose sur la capacité des filaments de délivrer à grande distance des intensités suffisantes pour induire in situ des effets non-linéaires à distance. Nous avons utilisé cette propriété pour identifier à distance des simulants d'aérosols biologiques ou des cibles solides. Enfin, l'ionisation de l'air dans le filament nous a permis de contrôler des décharges électriques de haute tension, ouvrant la voie vers un paratonnerre laser.
Mouketou, Missono Alain Stephen. "La technique de Z-scan : développement et application à l'étude de la réponse optique non-linéaire de matériaux nanocomposites". Paris 6, 2006. http://www.theses.fr/2006PA066069.
Pełny tekst źródłaEr-Rhaimini, Salih. "Reconstruction d'image par rétrodiffusion stimulée Raman et amélioration du rendement de conversion". Angers, 1995. http://www.theses.fr/1995ANGE0007.
Pełny tekst źródłaMauger, Sarah. "Couplage entre auto-focalisation et diffusion Brillouin stimulée pour une impulsion laser nanoseconde dans la silice". Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00638962.
Pełny tekst źródłaCambournac, Cyril. "Instabilités spatiales en milieu de Kerr : réseaux de solitons spatiaux et brisure de symétrie des solitons multimodes dans un guide plan". Phd thesis, Université de Franche-Comté, 2003. http://tel.archives-ouvertes.fr/tel-00008017.
Pełny tekst źródłaThomazeau, Isabelle. "Résolution temporelle, à l'échelle subpicoseconde, de non-linéarités optiques du 3ème ordre dans des milieux isotropes transparents". Paris 11, 1986. http://www.theses.fr/1986PA112148.
Pełny tekst źródłaOptical Kerr effect technique has been used to time resolve the third order nonlinearities of silicate glasses. Among them SF59 Schott glass may be a good optical shutter well suited for subpicosecond pump pulses. Its efficiency is of the same order of magnitude as that of liquid CS2 and takes advantage of temporal resolution limited by the pulses widths. Wave mixing experiments have been performed on liquid CS2, in the 620 nm – 650 nm frequency range. The associated electronic nonlinearities have been measured and the Kleinmann symmetry rule verified. The temporal behaviour of transient phase gratings has been analysed for a liquid (CS2) and glass (SF59). Two geometries have been built up: Raman-Nath and Bragg. The results obtained confirm the electronic and molecular theories which describe the relations encountered by the elements of the third order susceptibility tensor
Charlet, Gabriel. "Etude des formats de modulation et des méthodes de détection pour les transmissions multiplexées en longueurs d’ondes sur fibre optique au débit de 40Gb/s et 100Gb/s". Thesis, Paris 11, 2011. http://www.theses.fr/2011PA112008/document.
Pełny tekst źródłaModulation and detection methods have been studied to improve the performance of optical long distance communication systems. Polarization division multiplexed modulation and multilevel phase modulation format have been evaluated. Coherent detection associated with digital signal processing has been selected at the receiver side to optimize system performance. This receiver design allows especially to compensate linear distortions induced by fiber optics propagation very efficiently. After long distance propagation, optical signal to noise ratio is a major limitation. The other main limitation comes from non linear interactions of light and fiber optics which put a limit on the maximum power to be injected within fiber optics.The first wavelength division multiplexed transmission over long distances (>1000km) using coherent detection has been demonstrated.Various strategies have been proposed to minimize the impact of non linear effect. The impact of polarisation multiplexing has been quantified in configuration where chromatic dispersion is either regularly optically compensated within the line or digitally compensated at the receiver end.The proposition to use a polarization multiplexed format using only 2 phase levels as well as the algorithms capable to detect them has been done. The performance gain obtained compared to the convention solution using 4 phase levels has been demonstrated.At 100Gb/s bit rate, the demonstration of the first transmission over trans-oceanic distance has also been done.These research work have been used to define and then develop Alcatel-Lucent products which are now commercialized, at 40Gb/s by using a polarization multiplexed and 2 phase levels modulation format, and at 100Gb/s by using a polarization multiplexed 4 phase levels format
Berthereau, Anne. "Les matériaux vitreux pour l'optique non linéaire: - étude des verres à base d'oxyde de tellure a fort effet Kerr optique- le phénomène de génération de seconde harmonique dans un verre". Phd thesis, Bordeaux 1, 1995. http://www.theses.fr/1995BOR10660.
Pełny tekst źródłaKaassamani, Shatha. "Polarization Spectroscopy of High Order Harmonic Generation in Semiconductors Orbital angular momentum from semiconductor high-order harmonics All semiconductor enhanced highharmonic generation from a single nanostructured cone". Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASP091.
Pełny tekst źródłaSince its first observation, a decade ago, high harmonic generation (HHG) in crystals has proved to be an efficient, controllable and compact source of coherent XUV radiation. In this thesis, we investigate HHG in 2D materials, particularly graphene, and in different semiconductor crystals mainly zinc oxide, silicon, gallium arsenide and magnesium oxide. We find that the laser properties, such as its intensity, polarization and ellipticity, and the crystal properties are interrelated. Moreover, we shed the light on the role of the linear and nonlinear propagation effects mainly the Kerr effect, upon laser interaction with the crystal, which can significantly influence the high harmonic generation efficiency. Although this presents major limitations, we show that in some cases it turns out to be an advantage. Finally, we demonstrate the manipulation of the harmonic radiation at the source of the emission by patterning nanostructures to confine and enhance nanojoule laser pulses, and generate harmonic beams carrying orbital angular momentum. Lastly, we successfully image a micrometer-sized sample by the coherent diffractive imaging (CDI) technique based on solid-state harmonics
Bessin, Florent. "Experimental observation of different forms of modulation instability in passive fiber cavities". Thesis, Lille 1, 2019. http://www.theses.fr/2019LIL1R042/document.
Pełny tekst źródłaModulation instability (MI) in optics is a nonlinear process where a weak periodic perturbation exponentially grows at the expanse of a strong carrier wave as a result of the perfect balance between dispersion and non-linearity. In passive optical cavities, the coherent superposition between the driving field and the intra-cavity field adds a extra-degree of freedom to this mechanism that enriches its dynamics. In this thesis, we mostly led experimental study of MI in such devices made of optical fibers in unexplored regimes. In particular, we experimentally investigated this process in cavities that operate under weak normal dispersion. We showed that the MI dynamics in such regime is strongly modified compared to standard MI in cavities. We also studied the real-time dynamics of MI in the temporal domain highlighting that the generated temporal pattern can exhibit two distinct behaviors. A part of this work is also dedicated to the experimental study of the gain through loss mechanism. Under specific conditions this process can generate MI and tunable optical frequency combs. These studies are in pretty good agreement with theoretical models and numerical simulations. Finally, we explored analytically the process of coherent seeded MI. We reported that the dynamics of the process is phase-sensitive, which was confirmed experimentally by recording the power and phase evolution of the waves involved in the process
Delqué, Michaël. "Les solitons optiques spatiaux vectoriels et leurs interactions". Phd thesis, Université de Franche-Comté, 2006. http://tel.archives-ouvertes.fr/tel-00398835.
Pełny tekst źródłaL'objectif de cette thèse est d'étudier théoriquement et expérimentalement une nouvelle classe de solitons, les solitons vectoriels, qui consitent en la superposition d'enveloppes de polarisations distinctes mutuellement piégées. Pour comprendre l'existence de ces solitons à composantes multiples, il suffit d'imaginer un guide supportant plusieurs modes photo-induits par effet soliton. Lorsque plusieurs modes se propagent simultanément, un d'eux peut jouer le rôle de guide d'onde effectif pour d'autres modes supérieurs et former un soliton multicomposante. Dans notre travail, nous étudierons différents membres de cette famille ainsi que leur stabilité. Nous analyserons leurs dynamiques dans un guide planaire non linéaire.