Dissertations / Theses on the topic 'Toute la commutation optique'
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Zhang, Boyu. "Propagation des parois de domaines combinant courant polarisé et commutation toute optique." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS096/document.
Since the first observation of ultrafast demagnetization in Ni films arising from a pulsed laser excitation, there has been a strong interest in understanding the interaction between ultrashort laser pulses and magnetization. These studies have led to the discovery of all-optical switching (AOS) of magnetization in a ferrimagnetic film alloy of GdFeCo using femtosecond laser pulses. All-optical switching enables an energy-efficient magnetization reversal of the magnetic material with no external magnetic field, where the direction of the resulting magnetization is given by the right or left circular polarization of the light. The manipulation of magnetization through laser beam has long been restricted to one material, though it turned out to be a more general phenomenon for a variety of ferromagnetic materials, including alloys, multilayers and heterostructures, as well as rare earth free synthetic ferrimagnetic heterostructures. Recently, we have observed the same phenomenon in single ferromagnetic films, thus paving the way for an integration of all-optical writing in spintronic devices. Moreover, in similar materials, like [Co/Pt] or [Co/Ni] with high spin polarization and tunable perpendicular magnetic anisotropy (PMA), efficient current-induced domain wall (DW) motion can be observed in magnetic wires, where spin-orbit torque (SOT) or spin transfer torque (STT) provides a powerful means of manipulating domain walls, which is of great interest for several spintronic applications, such as high-density racetrack memory and magnetic domain wall logic. However, the current density required for domain wall motion is still too high to realize low power devices. This is within this very innovative context that my Ph.D. research has focused on domain wall manipulation in magnetic wires made out of thin film with strong perpendicular magnetic anisotropy combining both spin-polarized current and all-optical switching. Different material structures have been explored, in order to investigate the combined effects of helicity-dependent optical effect and spin-orbit torque or spin transfer torque on domain wall motion in magnetic wires based on these structures. We show that domain wall can remain pinned under one laser circular helicity while depinned by the opposite circular helicity, and the threshold current density can be greatly reduced by using femtosecond laser pulses. Our findings provide novel insights towards the development of low power spintronic-photonic devices
Simos, Christos. "Traitement ultrarapide de signaux optiques par effets non-linéaires quadratiques : échantillonnage optique et commutation spatiale par effet soliton." Limoges, 2002. http://www.theses.fr/2002LIMO0004.
The goal of this work is the study of the possibilities offered by the quadratic nonlinear effects for the realisation of ultrafast functions for all-optical processing of signals such as optical sampling, all optical switching and routing, wavelength demultiplexing, etc
Jeannes, Franck. "Dispositifs bistables à cavité-verticales pour la commutation tout-optique aux longueurs d'onde télécom." Aix-Marseille 3, 1996. http://www.theses.fr/1996AIX30040.
METIN, DAVID. "Comportement spatio-temporel de films non lineaires. Application a la commutation tout optique." Besançon, 1995. http://www.theses.fr/1995BESA2075.
Gicquel-Guezo, Maud. "Absorbant saturable ultra-rapide à minipuits quantiques pour le traitement tout-optique du signal." Rennes, INSA, 2004. http://www.theses.fr/2004ISAR0009.
This thesis deals with the study of saturable absorbers based on Fe-doped InGaAs/InP multiple quantum wells (MQW). The non-linear optical properties of excitonic absorption are exploited for all-optical regeneration at 1. 55mm. A numerical model is developed for the calculation of the non-linear optical properties of MQW structures. The efficiency of Fe doping to shorten the absorption relaxation time is experimentally demonstrated and explained by a dynamic model of the carriers capture by Fe atoms. The insertion of Fe doped MQW into a microcavity, which resonance is matched to excitonic transition, reduces the switching energy by a 50-factor and enhances the contrast ratio (CR) to 8dB. Such a CR value increases the transmission distance of a numerical signal by more than 1000km at 10Gb/s, with a constant transmission quality. The response time can be reduced to 290fs and the CR stays at a relatively high value of 5dB
Koppa, Pàl. "Commutation de données par reconnaissance d'adresse binaire." Phd thesis, Université Paris Sud - Paris XI, 1995. http://pastel.archives-ouvertes.fr/pastel-00714180.
Peng, Yi. "Single laser pulse switching in RE-based multilayers without Gd." Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0297.
The emerging field of ultrafast spin electronics integrates the ideas and concepts of magneto-optics and opto-magnetism with spin transport phenomena, supplemented with the possibilities offered by photonics for ultrafast low-dissipative manipulation and transport of information. The discovery of all-optical ultra-fast deterministic magnetization switching has opened up new possibilities for manipulating magnetization in devices using femtosecond laser pulses. HI-AOS is predominantly observed in Gadolinium-based Rare Earth (RE) / Transition Metals (TM) ferrimagnetic alloys or multilayers. Notably, it has recently been witnessed in materials without Gadolinium, such as the ferrimagnet Mn2RuxGa and the ferrimagnetic multilayer [Tb/Co]N. In this work, we tried to find new materials that can show single-shot helicity-independent all-optical switching (HI-AOS) and to understand the switching behavior, fundamental mechanism, and switching process in different materials and structures. Therefore, three main parts of work have been done in this thesis:• Study the CoLu alloy, where Lu has the same properties as Gd with small spin-orbit coupling (L=0). Perpendicular magnetic anisotropy can be obtained in 3 nm of Co100-xLux alloy with x varies between 22% and 42%. Besides, single-shot switching measurements in full film and 3 μm dots array show that nodeterministic switching of the magnetization can be observed. The results can be attributed to the low magnetization and, consequently, too-small angular momentum carried by the Lu element by atomistic simulations. • Single-shot switching in [RE/TM]N multilayers, where the RE layer could be rare-earth metal with larger spin-orbit coupling such as Tb and Dy, and their alloy with transition metals. Starting with [Tb/Co]5 and [Tb/Fe]4 multilayers, the single-shot switching has been extended to various multilayers, bilayers, and trilayers, making it a general phenomenon in Tb- and Dy-based multilayers, which have sperimagnetic properties coupled with transient metals. Interestingly, a complex structure of rings of opposite magnetization directions has been observed at high fluence. According to the pump-probe measurements,We tried to explain the switching mechanism and ring structures, which could be an in-plane reorientation precession mechanism. • Single-shot switching in [Co/Ho]N multilayers, which is a novel material system with the expectation of higher spin-orbit coupling compared to Tb and Dy. Surprisingly, even though the spin-orbit coupling in Ho ( as it is in Tb and Dy) is larger than that of in Gd, which should increase the dissipation of angular momentum to the lattice, the pulse duration/fluence state diagram is close to the Gd-based systems. Studying this new system could help bridge the single pulse reversal processes observed, on the one hand, in Gd-based, on the other hand, in the Tb or Dy-based heterostructures
Gicquel-Guézo, Maud. "Absorbant saturable ultra-rapide à multipuits quantiques pour le traitement tout-optique du signal." Phd thesis, INSA de Rennes, 2004. http://tel.archives-ouvertes.fr/tel-00010801.
Peinke, Emanuel Thomas. "Commutation tout optique ultra-rapide de micropiliers semi-conducteurs : propriétés fondamentales et applications dans le domaine de l'optique quantique." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAY030/document.
The resonance wavelengths of semiconductor optical microcavities can be changed within few picoseconds through the optical injection of free charge carriers. In this PhD thesis, we study in detail such “cavity switching” events for GaAs/AlAs planar and micropillar cavities, using the spontaneous emission of embedded QDs as an internal light source to probe the time-dependent frequencies of the cavity modes. Switching amplitudes as large as 34 mode linewidths are observed for optimized pumping conditions. Differential switching of micropillar modes is achieved by performing a localized injection of charge carriers, and modeled by taking into account their injection profile, diffusion and recombination processes. We investigate two important potential applications of cavity switching in the field of quantum optics. On one hand, we model the frequency conversion of light trapped in a cavity mode, which is induced by a switching event, and show that adiabatic and highly efficient frequency conversion can be achieved in properly designed planar cavities. On the other hand, cavity switching appears as a powerful resource to control in real-time the spontaneous emission of embedded emitters and more generally CQED effects. As a first example, we demonstrate the generation of few picosecond short pulses of incoherent light, using the spontaneous emission of switched QD-micropillars. We also show theoretically that cavity switching can be used to shape the time-envelope of single photon pulses emitted by a single QD, which is highly desirable for quantum-optical links and photonic quantum information processing
Teimoori, Hassan. "Commutation de paquets dans les réseaux optiques transparents à partir de fonctions logiques tout optiques." Phd thesis, Télécom ParisTech, 2007. http://pastel.archives-ouvertes.fr/pastel-00003084.
Teimoori, Hassan. "Commutation de paquets dans les réseaux optiques transparents à partir de fonctions logiques tout-optiques /." Paris : École nationale supérieure des télécommunications, 2008. http://catalogue.bnf.fr/ark:/12148/cb412463033.
Guo, Zongxia. "Electrical and optical manipulation of exchange bias." Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0204.
The rapid growth in scale and complexity of neural network architectures in today's machine learning and artificial intelligence applications is creating a significant demand for advanced hardware solutions. The semiconductor industry is actively seeking next-generation storage technologies that can offer improved speed, density, power consumption, and scalability. One such technology that shows great promise for high-performance data storage and processing is magnetoresistive random access memory (MRAM), which stores information in the magnetic state of materials. However, with the continuous requirement of high-density and ultrafast scenarios, antiferromagnet as the basic unit of MRAM shows obvious advantages. Antiferromagnetic materials have negligible macroscopic magnetism, making them highly robust to external magnetic fields. This property also allows for the absence of dipole interactions between adjacent bits, enabling higher-density integration. Additionally, antiferromagnetic materials exhibit high-frequency dynamics up to the terahertz range, theoretically enabling faster write speeds than ferromagnetic devices. However, such fully compensated magnetic moments make the magnetization state of the antiferromagnetic material difficult to manipulate and detect by traditional electrical methods. In this thesis, we demonstrate the antiferromagnetic exchange bias switching in three-terminal magnetic tunnel junctions and achieve electrical detection of antiferromagnetism by the tunnelling magnetoresistance with a ratio over 80%, which is two orders larger than previous methods. This is achieved by imprinting the state of antiferromagnet IrMn on the CoFeB free layer. We further realize current polarity-dependent switching, rather than current orientation-dependent switching of IrMn down to 0.8 ns. We identify two switching mechanisms, the heating mode and the spin-orbit torque driven mode, depending on the current pulse width. The latter case is supported by numerical simulations, which suggest that spin-orbit torque generated by Pt induces the precession of IrMn and exchange coupling at the IrMn/CoFeB interface determines the switching polarity of IrMn. Furthermore, to break the ferromagnetic and electrical write speed limit and further explore the antiferromagnetic switching speed, we experimentally realize exchange bias switching by a single femtosecond laser pulse. In the IrMn/CoGd structure, the perpendicular exchange bias is investigated for different IrMn thicknesses and CoGd concentrations. Using the optimized structure, the exchange bias was switched under a single femtosecond laser, and the dependence of the exchange bias variations with different laser fluence and pulse numbers was detailed investigated. The pump-probe time-resolved measurement is used to demonstrate the exchange bias switching time scale of less than 100 ps. The grain structure of polycrystalline IrMn films and the amorphous state of CoGd alloy layers are accurately described using atomistic simulations. The IrMn exhibits a faster demagnetization than ferromagnetic materials and each IrMn grain remagnetizing to a single-domain state in only 2 ps. In addition, the different grains of IrMn exhibit independent and stochastic probabilistic switching in the ultrafast time scale. The electrical and all-optical manipulation of exchange bias system allows ultrafast, field-free and energy-efficient control of antiferromagnet with high ordering temperature and thermal stability, making it highly suited to applications
Bin, Ngah Lufti Arif. "Synchronisation toute optique d’un réseau de communication quantique." Thesis, Nice, 2015. http://www.theses.fr/2015NICE4141/document.
This manuscript reports the development of fundamental resources for long distance quantum communication based on fibre telecom technology and non-linear optical waveguides. After a general introduction on quantum communication, the thesis is structured along three parts. The first part illustrates the development of two photonic polarization entanglement sources suitable for quantum networking. Both sources generate paired photons at telecom wavelength via spontaneous parametric down conversion (SPDC) in periodically poled lithium niobate waveguides (PPLN/W). They rely on type-II and type 0 phase matching, respectively. In the second part, two high quality heralded single photon sources are highlighted. The first one relies on on-chip generation and spatial multiplexing of heralded single photons towards achieving higher bit rates. The second one takes advantage of passive temporal multiplexing of a single SPDC process. Finally, an all-optical approach towards efficient and accurate synchronization of remote entangled photon pair sources within quantum relay architecture over long distances is presented. This particular synchronization technique highlights the use of ultra-fast picosecond pulsed telecom fiber laser, operating at 2.5 GHz repetition rate, acting as a master optical clock, enabling to accurately synchronize the emission of photon pairs in the telecom C-band of wavelengths at two remote locations. This innovative approach is applied for synchronizing two remote PLLN/W based sources operated at 2.5 GHz, and preliminary results on two-photon interference obtained with single photons coming from each source are shown and discussed
Blary, Karine. "Matrices de commutation optique sur InP." Lille 1, 2003. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2003/50376-2003-341-342.pdf.
Blary, Karine Decoster Didier Chazelas Jean. "Matrices de commutation optique sur InP." [S.l.] : [s.n.], 2003. http://www.univ-lille1.fr/bustl-grisemine/pdf/extheses/50376-2003-341-342.pdf.
Pellat, Dominique. "Bistabilité optique dans les microrésonateurs et applications aux systèmes de commutation optique." Aix-Marseille 3, 1995. http://www.theses.fr/1995AIX30054.
Grudzien, Thomas. "Commutation optique par bistables optiques et diodes laser." Paris 7, 1999. http://www.theses.fr/1999PA077265.
Cherfi, Djamila. "Structures intégrées sur InP pour la commutation optique." Thesis, Lille 1, 2013. http://www.theses.fr/2013LIL10188.
The aim of this work is the study of different ways of integration based on InP optical waveguides to obtain 2x2 optical switching matrixes. For this purpose, we started with the monolithic integration of InP waveguides and highly confinement dielectrics waveguides. The active part is composed of InP waveguides and the passive part is constituted of dielectric waveguides which are tapered and very compact. In spite of strong theoretical and technological efforts developed to reach our target up to now monolithic integration doesn’t lead to low insertion losses fitting with industrial needs. Nevertheless, we designed and fabricated a new InP waveguide which allows a good coupling with glass waveguides of Teem Photonics company. Finally, we designed and fabricated a Digital Optical Switch with the new InP waveguide. Its characterizations proved the advantage of this waveguide for the optical switching
Ouahbi, Thami Amine. "Fabrication de nouveaux matériaux pour l'optique non linéaire par orientation toute optique." Mémoire, Université de Sherbrooke, 2005. http://hdl.handle.net/11143/5738.
Liu, Yan. "Homogénéisation à toute fréquence et optique transformationnelle dans des milieux bi-anisotropes." Ecole centrale de Marseille, 2013. http://www.theses.fr/2013ECDM0011.
Sattler, Tobias. "Commutation ultrarapide de microcavités semiconductrices pour des applications à l'optique quantique." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY082/document.
The all-optical injection of free charge carriers into a semiconductor material can change the resonance frequency of an optical microcavity within few picoseconds and allows an ultrafast modification of light-matter interaction. In this PhD thesis, we study the switching of different types of cavities based on GaAs/AlAs materials and explore possible applications.When the resonance wavelength of a cavity is shifted on a timescale shorter than its storage time, the frequency of the stored light is up-converted. In this work, we study this effect experimentally for high Q planar microcavities, able to store light during several tens of picoseconds. Upon ultrafast switching, we observe a large frequency shift (around 17 mode linewidths) of stored light.In agreement with numerical simulations, we evidence an adiabatic behavior and an efficiency close to 100% for this conversion process.When embedded in a cavity, quantum dots can serve as an internal light source for probing cavity modes and their switching dynamics. We use this approach to study two different kinds of microcavities.On one hand, we inject an inhomogeneous distribution of free charge carriers into micropillars, whose interest for quantum optics experiments is well recognized. We observe drastically different switching behaviors for their cavity modes, due to the different overlaps between free carriers and field intensity distributions. This behavior is understood in a quantitative way on the basis of simulations taking into account the diffusion and recombination of electron-hole pairs.On the other hand, we explore the properties of a novel type of microcavity, ovoid ring resonators. We present a characterization of their optical properties, as well as switching experiments. These objects offer appealing perspectives for the fabrication of microlasers, and for quantum optics experiments such as controlling the Purcell effect in real time
PAYE, JEROME. "Fabry-perot non lineaire et effet stark optique : un dispositif de commutation optique ultra-rapide." Palaiseau, Ecole polytechnique, 1992. http://www.theses.fr/1992EPXX0008.
Bourgeois, Martin. "Commutation optique dans un cristal photonique à base de silicium." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ62578.pdf.
Présent, Dominique. "Architecture d'interconnexion de cartes de commutation ATM par bus optique." Versailles-St Quentin en Yvelines, 1996. http://www.theses.fr/1996VERS0006.
Hernandez, Yves. "Etudes technologiques, expérimentales et par simulation pour la commutation optique sur InP." Lille 1, 2001. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2001/50376-2001-307.pdf.
Ces études ont révélé une influence importante de la couche d'InGaAs sur le comportement optique des composants. Les composants en question sont du type commutateur cascade multibloc. Ils sont basés sur le couplage passif entre guides parallèles distincts. La commutation est effective par injection de porteurs de charge électrique qui modifie l'indice dans la zone concerné, pouvant ainsi empêcher ce couplage. La couche d'InGaAs est uniquement dédiée aux aspects électriques en permettant une bonne injection de porteurs de charge dans la zone active du composant. L'influence de cette couche sur le fonctionnement passif du composant a été mis en évidence par la méthode des faisceaux propagés en trois dimensions. Suite à ce constat nous avons redéfini des structures de composants cascade monobloc et DOS à partir d'une structure épitaxiale pensée pour diminuer l'influence optique de cette couche d'InGaAs. La structure monobloc a une topologie plus facilement réalisable que la structure multibloc. Les résultats de caractérisation ont confirmé notre hypothèse. La réalisation de commutateurs cascade multiblocs, avec et sans InGaAs ont démontré des comportements radicalement différents dans les deux cas de figure [. . . ]
DORGEUILLE, FRANCOIS. "Matrice de commutation optique 2x2 a portes amplificatrices integree sur inp." Paris 6, 1996. http://www.theses.fr/1996PA066739.
Fischer, Alexis. "Commutation en longueur d'onde de diodes lasers accordables par multistabilite optique." Besançon, 1998. http://www.theses.fr/1998BESA2014.
Chelli, Hatem. "Étude et réalisation d'un système bistable optique intrinsèque ultra-rapide." Paris 11, 1986. http://www.theses.fr/1986PA112334.
In this thesis, the realization and the characterization of an intrinsic optical device allowing ultrafast optical switching are presented. This work is based on the nonlinear effects which can be observed when optical waves propagate in a multilayer structure with thin film sandwiched between two semi-infinite media. Experimental studies are reported (in linear and nonlinear operation in which when the nonlinear part of the guiding structure is the film instead of the external media as considered in most of the studies performed up to date. The device structure consists of a silicon epitaxial layer grown on a sapphire substrate. A diffraction grating is etched on the silicon surface to allow light coupling in the silicon film. The grating is covered with a thin silver layer to get a better field enhancement in the waveguide. Taking into account the experimental constraints, numerical optimization of the waveguide structure has been realized to obtain guided modes excitation in optimal conditions. Experiments of excitation and characterization of the TE and TH device modes at low power have been performed. The nonlinear operation of the device has been studied using a Q-switched Nd-Yag laser. Switchings on the reflected beam and on the guided mode intensity have been observed with characteristic switching times lower than 700 ps. The switching time depends on the incident power and on the operating point. A theoretical model has been developed taking into account the competition between two effects: the electronic and thermal refractive index variation in silicon. The numerical analysis gives quite good description of the experimental results. It shows that nonlinear effects, and particularly the switching time, depend on three parameters: the temporal dependence of the excitation, the device geometry which determines thermal exchanges with the outside and the free carrier life time in the sample. When varying the duration of the excitation pulse and/or the free carrier life time, the theoretical model predicts bistable operation
Kali, Amal. "Etude des performances et des fonctionnalités des matrices de commutation pour le brassage optique." Rennes 1, 2004. http://www.theses.fr/2004REN10029.
Gavrel, Gildas. "Synthèse et étude de nouveaux di(hétéroaryl)éthènes pour la commutation optique." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00805808.
Lesecq, Marie. "Fonctionnalités actives en optique intégrée à base de fils optiques en filière InP : application à la commutation optique." Lille 1, 2007. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2007/50376-2007-127.pdf.
Rodriguez, Christophe. "Commutation optique sur InP : apports pour la fabrication de commutateurs de très hautes performances." Thesis, Lille 1, 2010. http://www.theses.fr/2010LIL10197/document.
New applications of optical switching require very high performance devices, i.e. a low switching times combined with very low crosstalk between two arms and a switching current of the order of a few tens of milliamps. This combination is extremely delicate to obtain, but the problem becomes more complicated with the addition of fiber to fiber losses used for integration, which is of the order of one decibel.The work described in this thesis concerns the above mentioned problem. It follows the different work in IEMN in this area. Here we first developed a multiple quantum well waveguide structure to increase mechanisms of index variation. Then, we optimized switches with very low crosstalk and also Mach-Zehnder interferometers. Then these devices were manufactured in a clean room and characterized. The results of this study were not as per our expectations due to excessive losses in optical waveguides.In parallel, we have designed, fabricated and characterized other types of diluted waveguides with a very thin core. We finally obtained coupling losses of 1.6 dB/face without anti-reflective coating, which would give 0.1 dB with such a coating. This very interesting result should be related to the fact that the refractive index variation obtained on these guides is very important, showing an effect of free carriers much higher than in conventional semiconductor guides. All these aspects make our waveguide an excellent candidate for high performance optical switches
Mével, Yves. "Étude d'une cellule acousto-optique à multi-transducteurs : Application à un dispositif de commutation de paquets optiques." Brest, 2003. http://www.theses.fr/2003BRES2025.
@This work deals with the theoretical study and experimental characterisations of an optical packet switch for telecommunication networks at a 1. 55 æm wavelength. This switch is based on acousto-optic interaction. This manuscript is decomposed in four parts: the presentation of different technologies of optical packet switching ; the remind of the physic of acousto-optic deflexion and all critical parameters of our component ; the study of two different architectures, and the conception of a component in which two deflectors are created and superimposed applying simultaneously two RF signals on a phased array transducers. An acousto-optic switch have been built with Paratellurite TeO2. The static performances of this component were evaluated on an experimental set-up ; the measurements make appear an important signal to noise ratio (SNR) and a low dependence according to the optical polarisation
Thery, Laurence. "La modulation de phase pour la commutation optique dans le système InP/GaInAsP." Grenoble INPG, 1992. http://www.theses.fr/1992INPG0170.
Aboujeib, Joumane. "Systèmes de commutation optique à base d'une cellule acousto-optique multi-transducteurs pour les réseaux de télécommunications : optimisation et caractérisation." Brest, 2008. http://www.theses.fr/2008BRES2015.
“All optical networks”, with optical routing and switching components, seems to be the way for telecommunication networks development. This work deals with the characterizations of free space optical packet switches based on acousto-optic technology. The adopted solution is the use of a Bragg cell in which two diffraction gratings can be superimpose simultaneously. The switch is made with a TeO2 crystal provided with piezoelectric planas phased array transducers, and a specific electronic command. In the first part of this work, we present the optical switching function in optical networks, and various technologies used to realize this function. Then, we recall the physical acousto-optic interaction in the Bragg regime, the operating principle of the rnulti-transducers acousto-optic cell, and the consequences of the superposition of two diffraction gratings in a single crystal. In a second section part, we present the design of the 2x2 switch. We study experimentally the spurious effects at the cell output and we deduce the switch crosstalk. After the optimization of the switch, the system is characterized. The measurements show that die switch presents low crosstalk, low switching time, low sensitivity to the polarization, and transparency with the transmission rate. We show in the last part, that using a Bragg cell with planar phased array transducers driven by an appropriate electronic command (based on the direct synthesis of frequency) allows to improve the bandwidth of the deflector compared to other solutions proposed in the literature
Naciri, Youssef. "Synchronisation de paquets optiques dans les réseaux de télécommunications : réalisation d'un module exploitant l'interaction acousto-optique." Brest, 2000. http://www.theses.fr/2000BRES2050.
Chauvin, Jérôme. "Molécules et matériaux polymères photochromes pour l'optique non linéaire du deuxième ordre: orientation, stabilité et photo-commutation." Cachan, Ecole normale supérieure, 1998. http://www.theses.fr/1998DENS0041.
The second order non linear optical properties (NLO) of polymers are due to an anisotropic distribution of suitable chromophores inside the polymer matrix. The pre-requisite of a non centrosymmetrical ordering of theses chromophores is still a topical question, because the poled-order decay is an irreversible process which tends to annihilate the nonlinear optical response of the material. One part of this work deals with the use of high Tg side-chain DR 1-polyimide to improve the orientational stability. Relaxation of polar orientation has been related to relaxation processes measured by second harmonic generation. The stability is very good after 10 hours at 120°C and the lifetime at room temperature is estimated to more than one year. This polar relaxation could be due to a sub-Tg transition located around 120°C by dielectric measurements. In a second part, we focus on the coupling of the NLO and photochromism effects. We used the photo-assisted poling method to orient the DR1 inside the polyimide matrix. This method has the advantage to induce no thermal degradation of the NLO active chromophores. Indeed, as thermal poling must be made at temperature near Tg, it usually leads to a substantial chemical degradation of organic chromophore in general and of azobenzene derivatives such as DR1 in particular, specially in polyimides which have Tg near 250°C. To realise a photoswitching of the NLO properties, we have synthesized a diarylethene with electron donnor and acceptor substituents. The studies of its properties has been made in solution and in polymer thin film. It shows the possible photoinduced of the NLO signal of a poly methyl methacrylate film doped with the diarylethene
Pradelles, Jonathan. "Association de structures diffractances 1D et de microsystèmes opto-électro-mécanique." Ecully, Ecole centrale de Lyon, 2006. http://bibli.ec-lyon.fr/exl-doc/jpradelles.pdf.
Starting upon established skills on realization of tunable f Perot-Fabry MOEMS filters, fabricated by micro-machining process on InP related materials, we designed a novel class of devices : Grating Enhanced MOENS (GEMOEMS) to bring solutions to optical cross-connect matter. These novel devices take advantage of the coupling between a diffraction grating and a conventional vertical MOENS structure to enhance particular diffraction orders and specific wavelengths. By this way, we propose several prospective designs (optimized using RCWA and FDTD numerical simulation methods) for specific optical functions such as a 1×2 optical switch and tunable add-drop. We design a demonstrator similar to an 1x2 switch. For the realization, varied technologies have been investigated to realized the grating and standard MOEMS process have been suit ot GEMOEMS. Experimental characterizations, in static and dynamics, show a beam transfer from the 1R order to the 0R order, depending on the applied voltage
Zegaoui, Malek. "Commutateurs électro-optiques à haute diaphotie sur InP." Lille 1, 2005. https://ori-nuxeo.univ-lille1.fr/nuxeo/site/esupversions/c6f05795-2fb1-4870-b629-d2872ae2204f.
Han, Bing. "Réseaux de transport optique flexibles : apport de la combinaison des domaines temporel et spectral pour adapter la granularité des ressources optiques aux besoins de l'opérateur." Electronic Thesis or Diss., Paris, ENST, 2018. http://www.theses.fr/2018ENST0018.
The ever increasing traffic demand is a big challenge for the operators to increase the network capacity while lowering CAPEX and OPEX. To address these challenges, it is expected to increase flexibility of the network resources allocation while realizing directly the IP traffic routing in the optical layer. In this background, the “TIme and Spectral optical Aggregation (TISA)” approach has thus been proposed to allow a purely optical aggregation with the finest possible granularity thanks to the combination of temporal and spectral domains. The main objective of this thesis was to realize a proof of concept of the TISA concept to demonstrate experimentally the feasibility of the TISA solution. To accomplish this objective, we have designed and realized a multi-band OFDM optical burst transmitter with a narrow linewidth fast tunable laser. This laser has been implemented by combining external cavity lasers with semiconductor optical amplifier based optical gates. The transmitter is able to generate OFDM bursts in both DP-QPSK and DP-16QAM modulation formats while introducing a small penalty compared to the continuous flows configuration. We have performed the transmission of these bursts through the TISA network and have measured the bit error rates, which show less than 1 dB penalty for both modulation formats. Our results clearly show the feasibility of the TISA solution and demonstrate the ability to perform a purely optical aggregation/disaggregation and transparent routing while offering a sub-wavelength granularity in both time and spectral domains at the optical layer level
SAUER, HERVE. "Etude theorique du fonctionnement dynamique de dispositifs a guide d'onde non lineaire pour la commutation optique." Paris 11, 1990. http://www.theses.fr/1990PA112023.
BERTRAND, FLORENT. "Etude experimentale et modelisation de structures guide d'ondes en semiconducteurs iii-v pour la commutation optique." Paris 11, 1997. http://www.theses.fr/1997PA112115.
Turki, Kaïs. "Contribution à l'étude des performances et des limites photoréfractives de InP:Fe : application à la commutation optique." Grenoble 1, 1993. http://www.theses.fr/1993GRE10185.
Lamère, Jean-François. "Commutation de la réponse ONL quadratique dans les matériaux moléculaires." Phd thesis, Université Paul Sabatier - Toulouse III, 2006. http://tel.archives-ouvertes.fr/tel-00136412.
Notre travail de thèse a consisté à trouver de nouvelles possibilités de commutation ONL à l'aide de calculs DFT et ZINDO.
Les commutations par processus chimique ont été étudiées dans le cas de la protonation de complexes de nickel, qui induit la rotation de l'hyperpolarisabilité et de l'oxydation partielle de tétrathiafulvalènes fonctionnalisés.
Les commutations par processus physique ont été envisagées dans le cas de la transition de spin de complexes de fer(III), de l'effet de la température sur l'équilibre acide-base de dérivés stilbènes et enfin d'un changement conformationnel d'un complexe de chrome et d'un composé diorganoboré.
Cayrefourcq, Ian. "Conception et fabrication de matrices de commutation optique en vue de la réalisation de modules de synthèse de retards temporels." Lille 1, 1998. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1998/50376-1998-387.pdf.
Ratovelomanana, Frédéric. "Contribution à la réalisation de circuits intégrés optoélectroniques de commutation spatiale ou de transposition de longueur d'onde." Grenoble INPG, 1997. http://www.theses.fr/1997INPG0092.
Moignard, Renaud. "Les composants à cristal liquide ferroélectrique sur circuit intégré : application à la commutation optique en espace libre." Brest, 1997. http://www.theses.fr/1997BRES2010.
Saadsaoud, Naïma. "Etude de nouvelles structures guide d'onde sur matériaux III-V pour la commutation optique et la photodétection." Valenciennes, 2010. http://ged.univ-valenciennes.fr/nuxeo/site/esupversions/5cf8d1cc-9ff9-4766-933c-ec996324ba76.
This thesis is based on technology and experiments. The gool was to check the validity of new concepts, which could not be predicted only thanks to modeling. We divided our book into 4 chapters, corresponding to the 4 types of new devices we fabricated and characterized, all based on a III-V ridge optical waveguide technology. These four devices are : Active Schottky contact InP optical waveguides for optical switching, GaAsSbN/GaAs double heterostructure optical waveguides for 1. 55µm optical telecommunication integrated optics, 1. 55µm high power, high frequency InP photodiodes based on the monolithic integration of a dilute multimode waveguide and modified PIN photodiode, GaAs PIN-waveguide photodiodes for 1. 3µm wavelength high speed photodetection. Which form the core of several projects in collaboration with NTU (Nanyung Technological University), and Thales Systèmes Aéroportés with the support of DGA, and Singapore Embassy (MERLION projetc)
Dupray, Valérie. "Etude détaillée de l'effet photoréfractif dans le phosphure d'indium dopé au fer : application a la commutation optique." Rouen, 1999. http://www.theses.fr/1999ROUES013.
Indre, Raluca Maria. "Analyse de performance des réseaux optiques à commutation en sous-longueur d'onde." Phd thesis, Télécom ParisTech, 2012. http://pastel.archives-ouvertes.fr/pastel-00838427.