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A mesure que les demandes dans le domaine de l'électronique de puissance tendent vers des conditions de plus en plus extrêmes (forte densité de puissance, haute fréquence, haute température,…), l'évolution des systèmes de traitement de l'énergie électrique se heurte aux limites physiques du silicium. Une nouvelle approche basée sur l'utilisation des matériaux semi-conducteurs grand gap permettra de lever ces limites. Parmi ces matériaux, le diamant possède les propriétés les plus intéressantes pour l'électronique de puissance: champ de rupture et conductivité thermique exceptionnels, grandes mobilités des porteurs électriques, possibilité de fonctionnement à haute température… Les récents progrès dans la synthèse du diamant par des méthodes de dépôt en phase vapeur (CVD) permettent d'obtenir des substrats de caractéristiques cristallographiques compatibles avec l'exploitation de ces propriétés en électronique de puissance. Cependant, l'utilisation du diamant en tant que matériau électronique reste toutefois délicate à ce jour du fait de la grande difficulté de trouver des dopants convenables (en particulier les donneurs) dans le diamant. En outre, certaines propriétés du diamant telles que sa dureté extrême et son inertie chimique, faisant de lui un matériau unique, posent aussi des difficultés dans son utilisation technologique. L'objectif de ces travaux de thèse a été dans un premier temps d'évaluer les bénéfices que pourrait apporter le diamant en électronique de puissance ainsi que l'état de l'art de sa synthèse par dépôt en phase vapeur. Ensuite, différentes étapes technologiques nécessaires à la fabrication de composants sur diamant ont été étudiées: Gravure RIE, dépôt de contacts électriques. Enfin, ces travaux ont été illustrés par la réalisation et la caractérisation de diodes Schottky, dispositifs élémentaires de l'électronique de puissance. Les résultats obtenus permettent d'établir un bilan des verrous scientifiques et technologiques qu'il reste à relever pour une exploitation industrielle de la filière diamant. / As applications in the field of power electronics tend toward more extreme conditions (high power density, high frequency, high temperature ...), evolution of electric power treatment systems comes up against physical limits of silicon, the main semiconductor material used in electronic industry for over 50 years. A new approach based on the use of wide bandgap semiconductor materials will permit to overcome those limits. Among these materials, diamond is a very attractive material for power electronics switch devices due to its exceptional properties: high electric breakdown field, high carriers mobilities, exceptional thermal conductivity, high temperature operating possibility... However, the use of diamond as an electronic material is still very problematic due to the difficulty in the synthesis of high electronic grade CVD diamond and to find suitable dopants (in particular donors) in diamond. Besides, some of the unique properties of diamond, such as its extreme hardness and chemical inertness that make it an attractive material also cause difficulties in its application. Nevertheless, recent progress in the field of chemical vapor deposition (CVD) synthesis of diamond allow the study of the technological steps (RIE etching, ohmic and Schottky contacts, passivation,...) necessary for future diamond power devices processing. This is the aim of this thesis. In a first section, the uniqueness of diamond, the promise it bears as a potential material for specific electronic devices and the difficulties related to its application were reviewed. Then, the different technological steps required for power switching devices processing were studied: RIE etching, Ohmic and Schottky contacts. Finally, these works were illustrated by carrying out and electrical characterizations of Schottky Barrier Diodes. The achieved results allow us to make a summary of scientific and technological locks that remain for an industrial exploitation of diamond in power electronic switch devices field.

Los solitones ópticos son paquetes de luz (haces y/o pulsos) que no se dispersan gracias al balance entre difracción/dispersión y no linealidad. Al propagarse e interactuar los unos con los otros muestran propiedades que normalmente se asocian a partículas. Las propiedades de los solitones ópticos en fibras ópticas y cristales han sido investigadas en profundidad durante las últimas dos décadas. Sin embargo, los solitones en mallas, o redes, ópticas, que podrían ser usados para procesado y direccionamiento totalmente óptico de señales, se han convertido en una nueva área de investigación. El principal objetivo de esta tesis es el estudio de nuevas técnicas para controlar solitotes en medios no lineales en mallas ópticas.El capítulo 2 se centra en ciertas propiedades de los solitones ópticos en medios no lineales cuadráticos. La primera sección presenta en detalle la existencia y estabilidad de tres familias representativas de solitones espacio temporales en dos dimensiones en series de frentes de onda cuadráticos no lineales. Se asume, además de la dispersión temporal del pulso, la combinación de difracción discreta que surge debido al acoplamiento débil entre frentes de onda vecinos. La otra sección da cuenta de la existencia y estabilidad de vórtices de solitones multicolores en retículo, consistentes en cuatro jorobas principales dispuestas en una configuración cuadrada. También se investiga la posibilidad de generarlos dinámicamente a partir de haces de entrada Gaussianos con vórtices anidados. La técnica de inducción de mallas ópticas ofrece un sinfín de posibilidades para la creación de configuraciones de guía de ondas con varios haces de luz no difractantes. El capítulo 3 presenta el concepto de estructuras reconfigurables ópticamente inducidas por haces no difractantes de Bessel mutuamente incoherentes en medios no lineales de tipo Kerr. Los acopladores de dos nucleos son introducidos y se muestra cómo calibrar las propiedades de conmutación de estas estructuras variando la intensidad de los haces de Bessel. El capítulo también discute varios escenarios de conmutación para solitones lanzados al interior de acopladores direccionales multinucleares ópticamente inducidos por apropiadas series de haces de Bessel. Es más, la propagación de solitones es investigada en redes reconfigurables bidimensionales inducidas ópticamente por series de haces de Bessel no difractantes. Se muestra que los haces anchos de solitones pueden moverse a través de redes con diferentes topologías casi sin pérdidas por radiación. Finalmente, se estudian las propiedades de las uniones X, que se crean a partir de dos haces de Bessel intersectantes. La respuesta no local de los medios no lineales puede jugar un papel importante en las propiedades de los solitones. El capítulo 4 trata el impacto de la no localidad en las características físicas exhibidas por los solitones que permiten los medios no lineales de tipo Kerr con una retícula óptica integrada. El capítulo investiga propiedades de diferentes familias de solitones en mallas en medios no lineales no locales. Se muestra que la no localidad de la respuesta no lineal puede afectar profundamente la movilidad de los solitones. Las propiedades de los solitones de gap también se discuten en el caso de cristales fotorefractivos con una respuesta de difusión no local asimétrica y en presencia de una malla inducida.El capítulo 5 trata del impacto de la no localidad en la estabilidad de complejos de solitones en medios no lineales de tipo Kerr uniformes. En primer lugar, se muestra que la diferente respuesta no local de los materiales tiene distinta influencia en la estabilidad de los complejos de solitones en el caso escalar. En segundo lugar, se da cuenta de una serie de resultados experimentales sobre solitones multipolares escalares en medios no lineales fuertemente no locales en 2D, incluyendo solitones dipolares, tripolares y de tipo pajarita, organizados en series de puntos brillantes fuera de fase. Finalmente, el capítulo estudia la interacción entre la no linealidad no local y el acoplamiento vectorial, enfatizando especialmente la estabilización de efectos vectoriales en complejos de solitones en medios no lineales no locales.Por último, el capítulo 6 resume los principales resultados obtenidos en la tesis y discute algunas cuestiones abiertas. / Optical solitons are light packets (beams and/or pulses) that do not broaden because of the proper balance between diffraction/dispersion and nonlinearity. They propagate and interact with one another while displaying properties that are normally associated with real particles. The properties of optical solitons in optical fibers and crystals have been investigated comprehensively during the last two decades. However, solitons in optical lattices, which might be used for all-optical signal processing and routing have recently emerged a new area of research. The main objective of this thesis is the investigation of new techniques for soliton control in nonlinear media with/without an imprinted optical lattice. Chapter 2 focuses on properties of optical solitons in quadratic nonlinear media. The first section presents in detail the existence and stability of three representative families of two-dimensional spatiotemporal solitons in quadratic nonlinear waveguide arrays. It is assumed in addition to the temporal dispersion of the pulse, the combination of discrete diffraction that arises because of the weak coupling between neighboring waveguides. The other section reports on the existence and stability of multicolor lattice vortex solitons, which comprise four main humps arranged in a square configuration. It is also investigated the possibility of their dynamical generation from Gaussian-type input beams with nested vortices. The technique of optical lattice induction opens a wealth of opportunities for creation of waveguiding configurations with various nondiffracting light beams. Chapter 3 puts forward the concept of reconfigurable structures optically induced by mutually incoherent nondiffracting Bessel beams in Kerr-type nonlinear media. Two-core couplers are introduced and it is shown how to tune the switching properties of such structures by varying the intensity of the Bessel beams. The chapter also discusses various switching scenarios for solitons launched into the multi core directional couplers optically-induced by suitable arrays of Bessel beams. Furthermore, propagation of solitons is investigated in reconfigurable two-dimensional networks induced optically by arrays of nondiffracting Bessel beams. It is shown that broad soliton beams can move across networks with different topologies almost without radiation losses. Finally, properties of X-junctions are studied, which are created with two intersecting Bessel beams.Nonlocal response of nonlinear media can play an important role in properties of solitons. Chapter 4 treats the impact of nonlocality in the physical features exhibited by solitons supported by Kerr-type nonlinear media with an imprinted optical lattice. The chapter investigates properties of different families of lattice solitons in nonlocal nonlinear media. It is shown that the nonlocality of the nonlinear response can profoundly affect the soliton mobility. The properties of gap solitons are also discussed for photorefractive crystals with an asymmetric nonlocal diffusion response and in the presence of an imprinted optical lattice.Chapter 5 is devoted to the impact of nonlocality on the stability of soliton complexes in uniform nonlocal Kerr-type nonlinear media. First, it is shown that the different nonlocal response of materials has different influence on the stability of soliton complexes in scalar case. Second, experimental work is reported on scalar multi-pole solitons in 2D highly nonlocal nonlinear media, including dipole, tripole, and necklace-type solitons, organized as arrays of out-of-phase bright spots. Finally, the chapter addresses the interplay between nonlocal nonlinearity and vectoral coupling, specially emphasizing the stabilization of vector effects on soliton complexes in nonlocal nonlinear media.Finally, Chapter 6 summarizes the main results obtained in the thesis and discusses some open prospects.

A vacuum interrupter is a switching device used in vacuum circuit breakers, which are widely employed in medium voltage circuits for interrupting the short-circuit fault currents. The vacuum interrupter is the chamber in which the arc extinction and hence the current interruption takes place. On the occurrence of a fault, the breaker mechanism separates the contacts of the vacuum interrupter. As the contacts separate, an arc is established between the contacts. The arc evolves in the contact space and extinguishes at or near the current zero, thus interrupting the current. The processes of arc ignition, evolution and extinction are very complex. These processes are fundamental to the design and the performance of the vacuum interrupter and hence the circuit breaker. The evolution of the arc predominantly depends on the short-circuit current, the design and metallurgy of the contacts. The evolution of the vacuum arc has been the focal point of considerable research activity. Significant effort has been concentrated to understand the various modes of the arc, the transition between the modes, the arc movement and the dependency on the contact design and finally the effect of the arc evolution on the current interruption performance of the vacuum interrupter. The voltage across the contacts during the arcing, termed as the arc voltage, has been a focal point of several research projects. Research has shown that the arc voltage depends strongly on the mode and the evolution process of the arc. The dependency is observed with respect to the magnitude and the nature of the arc voltage. This dependency has been established through the comparison of the arc voltage trace and the actual arc photographs. The arc voltage is thus an important parameter in understanding the arcing process in the interrupter. Arc voltage could also be utilised to compare the arcing behaviour in vacuum interrupters with different contact geometries and metallurgies. Having understood how the arc voltage depends on the arc modes and how it can be used to analyse the arcing performance of the interrupter, this work aims to establish experimentally the dependency of the arc voltage on fundamental parameters of the short-circuit current and the contact design. The variation of the arc voltage is studied with respect to the magnitude of the short-circuit current. It is seen that the magnitude of the arc voltage is higher, for a higher short-circuit current. This dependency is also reflected in the nature of the arc voltage waveform. The effect of cumulative short- circuit operations has been understood through the study of arc voltage variation with respect to the accumulated arcing time. It has been found that the arc voltage consistently decreases as the accumulated arcing time increases. The effect of the contact diameter on the arc evolution has been studied by comparing the arc voltage variations for contacts of different diameters for the same short-circuit current. It is observed that the variation of arc voltage with respect to the contact diameter depends on the type of contact. In the case of radial magnetic field contacts, it has been observed that the arc voltage is lower for a contact with lower diameter. Whereas in the case of axial magnetic field contacts there is an inverse relation between the contact diameter and the arc voltage. Finally, the effect of the type and distribution of the magnetic field on the arc voltage variation as well as the contact erosion has been studied. In general, the observations show that the arc voltage magnitude for the radial magnetic field geometry is higher than the axial magnetic field geometry. Also, there is a significant difference in the appearance of the arc voltage waveforms for the arcs under the two types of magnetic fields. Finite element simulations and short-circuit evaluations have shown that the axial magnetic field contact system with 90 deg coil orientations yield a more uniform distribution of the flux density and hence lower erosion of the contacts. These results show a clear dependence of the arc voltage on the various above mentioned parameters. Thus the arc voltage could be utilised as a diagnostic parameter during the evaluation of the vacuum interrupter. In the present scenario, significant research is being done to increase the breaking capacity of the interrupters. This calls for optimization of design of the existing contacts and the design of novel contact geometries. The arc voltage would be used as an important diagnostic tool in this process. Also, the utilization of vacuum interrupter in high voltage and extra high voltage circuits is being explored. This application requires increase in the contact gap or series connection of gaps. The arc behaviour in longer gaps and gaps connected in series would be an important research area. Again the arc voltage could be used to study the arc evolution in these specialised conditions. The experiments in this research work have been performed on commercial vacuum interrupters. For a dedicated research on vacuum arcs and vacuum interrupter contacts, development of a vacuum arc research facility has also been attempted as a part of this research work.

This thesis deals with study of durability of low voltage switching devices components. It describes components of circuit breaker and low voltage contactor and contains function models of these devices in various states. Based on model analysis, components that can get worn, damaged or destroyed were selected. Further practical experiments on two samples of circuit breakers from different manufacturers were executed to verify their technical parameters and parts durability. Failure of some components can cause switching device to malfunction.

Power Quality (PQ) has gained a lot of importance in the last decade. Several solutions to power quality problems have been proposed and developed. With the advent of solid state technology and power electronics in the power system protection devices, faster switching is achievable. In order to control and minimize the power quality problems which occur in extremely short times of less than 100ms, the need arises for a selection of devices that can switch faster than today. Also, the economic losses that occur in the network due to the power quality problems increase the incentive to transform the existing devices into faster and e fficient devices. This transformation can be seen as valuable from both a technical and economical point of view to the distribution networks today where a large number of customers are connected. However, in order to interpret the value these fast switching devices render to the distribution network a prior study is required. This thesis presents a picture of the devices that can be suitable for fast switching in today’s distribution network, and how to determine their value to the distribution network. Further it summarizes the research work related to this field. The description of the devices and technical aspects is presented first. A literature review of proposed devices is given. The technical aspects of power quality and its problems is described. An approach to estimate the value of the fast switching devices is detailed from different literature. The study shows that fast switching devices can be worthy to invest in when seen from a distribution network’s perspective provided that different technical aspects are taken into account.

Thesis (M. Tech. - Engineering: Electrical, Department Electronic Engineering, Faculty of Engineering and Technology)--Vaal University of Technology. / Curing of materials in order to obtain different properties has been a practice for many years. New developments in composite materials increase the need to control certain variables during the curing process. One very significant variable is temperature. Temperature control by itself is an old practice, however when the need for repeatedly controlling the process accurately over long periods of time arises, a system is required that outperforms normal manual control. One of the aspects within such a system that needs to be considered is the ability to replicate the temperatures within an oven which were originally used for a specific material’s curing profile. This means that a curing profile would need to be defined, saved for later and finally be interpreted correctly by the controlling system. Different control methods were simulated to enable the system to control the temperature which has been defined by literature. This dissertation introduces a variation on the standard control methods and shows improved results. Switching the oven on and off in order to increase or decrease internal oven temperature seems simple, but can cause switching devices to decrease their operational life span, if not designed carefully. A combination switch was introduced which harnesses the advantages of two very common switching devices to form an improved combination switch. Software for the personal computer environment, as well as software for the embedded environment were developed and formed a control system that produced acceptable results for temperature control. Accuracies of 98% and more were achieved and found to be acceptable according to standard engineering control practices. An accurate temperature profile controller was designed, simulated and built in order to control the temperature inside a specific curing oven which, in turn, determined the curing properties of specific materials. The overall results were satisfactory which lead to achieving the objectives outlined in this dissertation.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / One of the main goals of the electric utilities is to provide energy to its customers in a reliable and low cost way. Traditionally, the electricity sector regulatory commissions impose continuity targets, which must be carried out, to avoid great penalties. For many years, the electric utilities have adopted the practice of allowing the increment of temporary interruptions, aiming the reduction of permanent interruptions in energy supply, through coordinated protection schemes. However, due to the increase growing in electronic loads, and the existence of complex power-driven industrial processes, there is a less tolerance in short duration interruptions events. Therefore, the reliability must be characterized as widely way, considering the occurrence of such disturbances. The definition of protection devices types, and its arrangement in the feeder, enables the restriction of faults propagation, reducing the number of consumers subject to interruptions in energy supply. Similarly, the allocation of switching devices in an optimized way, provides a reduction of the interruptions duration, allowing the isolation of portions of the network subject to failure, the reconfiguration of the feeder and restoration of the supply to the consumer, in permanent interruptions cases. Targeting these factors, in this work are proposed two methods to optimize the reliability of electrical distribution systems. The optimization with a single objective is based on optimized allocation of protective and switching devices in the feeder, aiming the minimization of the reliability indices that considers the occurrence of permanent interruptions in energy supply. It is possible the choice of different indices, considering parameters such as load, number of consumers, and energy costs related to the occurrence of interruptions. The protection scheme, in this case is pre-defined (coordinated or selective), and applied to all reclosers allocated in the process of optimization, as well as the breaker of the substation. The second methodology - called double objective - is based on simultaneous minimization of reliability index that take into account the occurrence of permanent interruptions, and the indicator MAIFIE (Momentary Average Interruption Event Frequency Index), which considers the incidence of events that cause temporary interruptions in energy supply. Thus, besides the allocation of protection and switching devices, the optimization consists in definition of the protection scheme to be employed in reclosers and circuit breaker at the substation. Both formulations result in models of nonlinear programming with discontinuous and non-differentiable objective functions, subject to non-linear restrictions. These restrictions reflect in economic and technical limitations, such as coordination and selectivity between the protective devices, topology of the feeder, maximum number of devices available for allocation, and others. In order to find the best solution of the problem with single objective, a Simple Genetic Algorithm is proposed. A conjunct of best solutions of the dual objective problem was accomplished by using Multiobjective Genetic Algorithm. Among these, the most appropriate solution is selected through the use of Fuzzy Inference System. The performance of the algorithms and the quality of the solutions were verified by submitting a real 421 bus distribution system in the process of optimization. The results are commented and compared with the commonly practices used by electric companies. / Uma das principais metas das empresas concessionárias é fornecer energia a seus clientes de forma confiável e com baixo custo. Tradicionalmente, órgãos reguladores do setor elétrico estabelecem metas de continuidade, que devem ser satisfeitas sob pena da aplicação de vultosas multas. Durante muitos anos, as concessionárias têm adotado a prática de permitir o incremento das interrupções temporárias, visando à diminuição na ocorrência das interrupções permanentes no fornecimento de energia, pelo emprego do esquema de proteção coordenado. Entretanto, com o crescente aumento das cargas eletrônicas, e a existência de processos industriais automatizados cada vez mais complexos, existe uma menor tolerância à ocorrência de interrupções de curta duração. Logo, a confiabilidade deve ser caracterizada de forma mais ampla, considerando a ocorrência deste tipo de distúrbio. A definição dos tipos de dispositivos de proteção, e a disposição dos mesmos em locais específicos do alimentador, possibilitam restringir a propagação de faltas, reduzindo o número de consumidores submetidos a interrupções no fornecimento de energia. De forma semelhante, a alocação de chaves de manobras de maneira otimizada provê meios de reduzir a duração das interrupções, possibilitando a isolação de trechos da rede sob condição de falta, a reconfiguração do alimentador e o restabelecimento do fornecimento à parte dos consumidores, caso ocorram interrupções permanentes. Visando estes fatores, neste trabalho são propostas duas metodologias de otimização da confiabilidade de sistemas elétricos de distribuição. A otimização com objetivo único consiste na alocação de dispositivos de proteção e manobras no alimentador, visando à minimização de indicadores de confiabilidade que consideram a ocorrência de interrupções permanentes no fornecimento de energia. É possível a escolha de diferentes indicadores, considerando parâmetros como: carga, número de consumidores, energia e custos relacionados à ocorrência de interrupções. O esquema de proteção, neste caso é pré-definido (coordenado ou seletivo), sendo aplicado a todos os religadores alocados no processo de otimização, inclusive ao disjuntor da subestação. A segunda metodologia denominada duplo objetivo consiste na minimização simultânea de um indicador de confiabilidade que considera a ocorrência de interrupções permanentes, e do indicador MAIFIE (Momentary Average Interruption Event Frequency Index), que considera a ocorrência de eventos causadores de interrupções temporárias no fornecimento de energia. Desta forma, além da alocação dos dispositivos de proteção e manobras, o processo de otimização visa definir o esquema de proteção a ser empregado nos religadores, bem como no disjuntor da subestação. Ambas as formulações resultam em modelos de programação não-lineares, com funções objetivo descontínuas e não diferenciáveis, sujeitas a restrições não-lineares. Estas restrições refletem limitações técnicas e econômicas, tais como coordenação e seletividade entre os dispositivos de proteção, topologia do alimentador, número máximo de dispositivos disponíveis para alocação, entre outras. Na busca da melhor solução do problema com objetivo único é empregado o Algoritmo Genético Simples. Um conjunto de soluções ótimas do problema duplo objetivo é obtido utilizando o Algoritmo Genético Multiobjetivo. Dentre estas, a solução mais adequada é selecionada por meio de um Sistema de Inferência Nebulosa. O desempenho dos algoritmos e a qualidade das soluções foram verificados submetendo um sistema de distribuição real de 421 barras ao processo de otimização. Por fim, os resultados são comentados e comparados com as práticas mais utilizadas pelas concessionárias.

Le premier volet de cette thèse est consacré à la modélisation des phénomènes de transport dans le LN. Partant d'une analyse critique des modèles de bande usuels, nous montrons leur inadéquation dans le cas du LN et nous proposons un modèle de saut basé sur la théorie des petits polarons. Nous étudions d'abord par simulation Monte-Carlo la décroissance d'une population de polarons liés NbLi4+ relaxant vers des pièges profonds FeLi3+. Nous montrons que les pièges FeLi3+ ont des rayons effectifs particulièrement grands, rayons qui augmentent encore à température décroissante, et limitent considérablement les longueurs de diffusion des polarons. Les résultats de simulations sont ensuite confrontés aux résultats expérimentaux obtenus par différentes techniques ; Absorption photo-induite, Raman, Enregistrement holographique et Pompe-sonde. Le deuxième volet de cette thèse est consacré aux applications électro-optiques dans le LN périodiquement polarisé (PPLN). Sous l’effet d’une tension électrique, l’indice de réfraction du PPLN est périodiquement diminué et augmenté, formant ainsi un réseau d’indice activable électriquement. Un premier composant utilisant l’effet électro-optique dans du PPLN a été développé et démontré expérimentalement. Dans ce composant, la lumière est défléchie sous l’effet de la tension électrique par le réseau d’indice. Ce déflecteur de Bragg atteint une efficacité de diffraction proche de 100% avec une faible tension de commande de l’ordre de 5 V. Un deuxième composant a également été proposé, où la lumière se propage perpendiculairement aux parois de domaines du PPLN. Dans cette configuration un réflecteur de Bragg électro-optique peut être réalisé / The first part of this thesis is devoted to the modeling of transport phenomena in the LN. From a critical analysis of the usual band models, we show their inadequacy in the case of LN and we propose a hopping model based on the theory of small polarons. We first study by Monte-Carlo simulation the population decay of bound polarons NbLi4+ in deep traps FeLi3+. We show that the traps (FeLi3+) have particularly large effective radii, which increase further at decreasing temperature, and considerably limit the diffusion lengths of the polarons. The results of simulations are then compared with experimental results obtained by different techniques; Light-induced absorption, Raman, Holographic storage and Pump-Probe. The second part of this thesis is devoted to electro-optical applications in the periodically poled LN (PPLN). Under the effect of an electrical voltage, the refractive index of the PPLN is periodically decreased and increased, thus forming an electrically activatable index grating. A first component using the electro-optical effect in PPLN has been developed and demonstrated experimentally. In this component, the light is deflected under the effect of the electrical voltage by the index grating. This Bragg deflector achieves a diffraction efficiency of close to 100% with a low drive voltage of the order of 5 V. A second component has also been proposed, where light propagates perpendicularly to the domain walls of the PPLN. In this configuration an electro-optic Bragg reflector can be realized