Surface plasmon-polaritons are optical surface waves formed through the interaction of photons with free electrons at the surface of metals. They offer interesting applications in a broad range of scientific fields such as physics, chemistry, biology, and material science. However, many of such applications face limitations imposed by the high propagation losses of these waves at visible and near-infrared wavelengths, which result mainly from power dissipation in the metal. In principle, the propagation losses of surface plasmon-polaritons can be compensated through optical amplification. The objective of this thesis is to provide deeper insights on the physics of surface plasmon-polariton amplification and spontaneous emission in surface plasmon-polariton amplifiers through theoretical and experimental vehicles applied (but not necessarily restricted) to a particular plasmonic mode termed long-range surface plasmon-polariton. On the theoretical side, the objective is approached by developing a realistic theoretical model to describe the small-signal amplification of surface plasmon-polaritons in planar structures incorporating dipolar gain media such as organic dye molecules, rare-earth ions, and quantum dots. This model takes into account the inhomogeneous gain distribution formed near the metal surface due to a non-uniform excitation of dipoles and due to a position-dependent excited-state dipole lifetime that results from near-field interactions between the excited dipoles and the metal. Also, a theoretical model to describe the amplified spontaneous emission of surface plasmon-polaritons supported by planar metallic structures is developed. This model takes into account the different energy decay channels into which an exited dipole located in the vicinity of the metal can relax. The validity of this model is confirmed through experimentation. On the experimental side, the objective is approached by providing a direct experimental demonstration of complete loss compensation in a plasmonic waveguide. The experiments are conducted using the long-range surface plasmon-polariton supported by a symmetric thin gold waveguide incorporating optically pumped organic dye molecules in solution as the gain medium. Also, an experimental study of spontaneous emission in a long-range surface plasmon-polariton amplifier is presented. It is shown that this amplifier benefits from a low spontaneous emission into the amplified mode, which leads to an optical amplifier with low noise characteristics. The experimental setup and techniques are explained in detail.

Surface plasmon-polaritons are optical surface waves formed through the interaction of photons with free electrons at the surface of metals. They offer interesting applications in a broad range of scientific fields such as physics, chemistry, biology, and material science. However, many of such applications face limitations imposed by the high propagation losses of these waves at visible and near-infrared wavelengths, which result mainly from power dissipation in the metal. In principle, the propagation losses of surface plasmon-polaritons can be compensated through optical amplification. The objective of this thesis is to provide deeper insights on the physics of surface plasmon-polariton amplification and spontaneous emission in surface plasmon-polariton amplifiers through theoretical and experimental vehicles applied (but not necessarily restricted) to a particular plasmonic mode termed long-range surface plasmon-polariton. On the theoretical side, the objective is approached by developing a realistic theoretical model to describe the small-signal amplification of surface plasmon-polaritons in planar structures incorporating dipolar gain media such as organic dye molecules, rare-earth ions, and quantum dots. This model takes into account the inhomogeneous gain distribution formed near the metal surface due to a non-uniform excitation of dipoles and due to a position-dependent excited-state dipole lifetime that results from near-field interactions between the excited dipoles and the metal. Also, a theoretical model to describe the amplified spontaneous emission of surface plasmon-polaritons supported by planar metallic structures is developed. This model takes into account the different energy decay channels into which an exited dipole located in the vicinity of the metal can relax. The validity of this model is confirmed through experimentation. On the experimental side, the objective is approached by providing a direct experimental demonstration of complete loss compensation in a plasmonic waveguide. The experiments are conducted using the long-range surface plasmon-polariton supported by a symmetric thin gold waveguide incorporating optically pumped organic dye molecules in solution as the gain medium. Also, an experimental study of spontaneous emission in a long-range surface plasmon-polariton amplifier is presented. It is shown that this amplifier benefits from a low spontaneous emission into the amplified mode, which leads to an optical amplifier with low noise characteristics. The experimental setup and techniques are explained in detail.

Surface plasmon-polaritons are optical surface waves formed through the interaction of photons with free electrons at the surface of metals. They offer interesting applications in a broad range of scientific fields such as physics, chemistry, biology, and material science. However, many of such applications face limitations imposed by the high propagation losses of these waves at visible and near-infrared wavelengths, which result mainly from power dissipation in the metal. In principle, the propagation losses of surface plasmon-polaritons can be compensated through optical amplification. The objective of this thesis is to provide deeper insights on the physics of surface plasmon-polariton amplification and spontaneous emission in surface plasmon-polariton amplifiers through theoretical and experimental vehicles applied (but not necessarily restricted) to a particular plasmonic mode termed long-range surface plasmon-polariton. On the theoretical side, the objective is approached by developing a realistic theoretical model to describe the small-signal amplification of surface plasmon-polaritons in planar structures incorporating dipolar gain media such as organic dye molecules, rare-earth ions, and quantum dots. This model takes into account the inhomogeneous gain distribution formed near the metal surface due to a non-uniform excitation of dipoles and due to a position-dependent excited-state dipole lifetime that results from near-field interactions between the excited dipoles and the metal. Also, a theoretical model to describe the amplified spontaneous emission of surface plasmon-polaritons supported by planar metallic structures is developed. This model takes into account the different energy decay channels into which an exited dipole located in the vicinity of the metal can relax. The validity of this model is confirmed through experimentation. On the experimental side, the objective is approached by providing a direct experimental demonstration of complete loss compensation in a plasmonic waveguide. The experiments are conducted using the long-range surface plasmon-polariton supported by a symmetric thin gold waveguide incorporating optically pumped organic dye molecules in solution as the gain medium. Also, an experimental study of spontaneous emission in a long-range surface plasmon-polariton amplifier is presented. It is shown that this amplifier benefits from a low spontaneous emission into the amplified mode, which leads to an optical amplifier with low noise characteristics. The experimental setup and techniques are explained in detail.

Surface plasmon-polaritons are optical surface waves formed through the interaction of photons with free electrons at the surface of metals. They offer interesting applications in a broad range of scientific fields such as physics, chemistry, biology, and material science. However, many of such applications face limitations imposed by the high propagation losses of these waves at visible and near-infrared wavelengths, which result mainly from power dissipation in the metal. In principle, the propagation losses of surface plasmon-polaritons can be compensated through optical amplification. The objective of this thesis is to provide deeper insights on the physics of surface plasmon-polariton amplification and spontaneous emission in surface plasmon-polariton amplifiers through theoretical and experimental vehicles applied (but not necessarily restricted) to a particular plasmonic mode termed long-range surface plasmon-polariton. On the theoretical side, the objective is approached by developing a realistic theoretical model to describe the small-signal amplification of surface plasmon-polaritons in planar structures incorporating dipolar gain media such as organic dye molecules, rare-earth ions, and quantum dots. This model takes into account the inhomogeneous gain distribution formed near the metal surface due to a non-uniform excitation of dipoles and due to a position-dependent excited-state dipole lifetime that results from near-field interactions between the excited dipoles and the metal. Also, a theoretical model to describe the amplified spontaneous emission of surface plasmon-polaritons supported by planar metallic structures is developed. This model takes into account the different energy decay channels into which an exited dipole located in the vicinity of the metal can relax. The validity of this model is confirmed through experimentation. On the experimental side, the objective is approached by providing a direct experimental demonstration of complete loss compensation in a plasmonic waveguide. The experiments are conducted using the long-range surface plasmon-polariton supported by a symmetric thin gold waveguide incorporating optically pumped organic dye molecules in solution as the gain medium. Also, an experimental study of spontaneous emission in a long-range surface plasmon-polariton amplifier is presented. It is shown that this amplifier benefits from a low spontaneous emission into the amplified mode, which leads to an optical amplifier with low noise characteristics. The experimental setup and techniques are explained in detail.

Les nanocristaux de Silicium (SiNCs) de taille inférieure à 5 nm sont des matériaux qui présentent une intense photoluminescence (PL) et capables d’amplification optique. Cette dernière propriété est un pré-requis à l’obtention d’émission stimulée sous pompage optique. Atteindre l’émission stimulé (et l’effet laser) à partir de nanostructures basées sur Si est d’un intérêt particulier dans le domaine de la photonique à base de silicium. Le but de ce travail était (i) d’étudier les propriétés optiques fondamentales de SiNCs, (ii) de concevoir et de réaliser un cristal photonique présentant une efficacité d’extraction augmentée et (iii) d’explorer la possibilité d’améliorer l’amplification optique des émetteurs de lumière à base de SiNCs en les combinant avec un cristal photonique à deux dimensions. / Silicon nanocrystals (SiNCs) of sizes below approximately 5 nm are a material with an efficient room-temperature photoluminescence (PL) and optical gain. Optical gain is a prerequisite for obtaining stimulated emission from a pumped material, and the achievement of stimulated emission (and lasing) from Si-based nanostructures is of particular interest in the field of silicon photonics. The aim of this work was (i) to investigate fundamental optical properties of SiNCs, (ii) to design and prepare a photonic crystal with enhanced light extraction efficiency and (iii) to explore a possibility of enhancing optical gain of light-emitting SiNCs by combining them with a two-dimensional photonic crystal.

O surgimento de novos serviços que requerem uma largura de banda cada vez maior, bem como o crescente número de usuários de tais serviços, têm introduzido desafios às empresas operadoras de telecomunicações em sua capacidade de atender a estas demandas sem perda apreciável da qualidade de serviço e mantendo, ainda assim, os custos num nível aceitável pelos usuários. Neste contexto, redes ópticas passivas (PONs) vêm atraindo grande interesse em anos recentes. Na sua variante de longo-alcance, as redes PON permitem uma consolidação do uso dos equipamentos e centrais de serviço requeridos, reduzindo custos operacionais e de instalação. Uma das formas de atingir este maior alcance dá-se por meio da inserção de amplificadores ópticos nas redes de acesso. Neste trabalho, portanto, estudaram-se alguns tipos de amplificadores ópticos e suas possíveis aplicações em redes de acesso, levando a topologias de longo alcance e alta capacidade. Foram realizadas avaliações experimentais de um extensor, baseado em amplificadores ópticos semicondutores (SOAs), na rede GPON do CPqD, sob a Meta 3 do Projeto GIGA, possibilitando a obtenção de uma topologia do tipo Fiber-to-the-Building (FTTB) com 80 km de extensão e 128 usuários atendidos por uma única central de serviço. Além dessas validações experimentais, foram simulados computacionalmente SOAs com características otimizadas bem como sistemas que utilizam fibras dopadas com érbio bombeadas remotamente, sendo que nestes últimos, atingiram-se distâncias superiores a 100 km. / The emergence of new services which require an increasing bandwidth, as well as the growing number of users of such services, have introduced challenges to the network operators in regard to their capacity of supporting these demands with no penalty on the required quality of service, while keeping the costs at an acceptable level for the users. In this context, passive optical networks (PONs) have attracted a great deal of interest in recent years. In the long-reach configuration, PON networks allow for a consolidation of equipament usage, reducing operational and installation costs. One way to achieve this longer reach is by the insertion of optical amplifiers in the access network. Therefore, in our work, we have investigated several optical amplifier configurations, as well as their application in access networks, leading to longreach and high capacity network topologies. Experimental evaluations of an extender, based on semiconductor optical amplifiers, were carried out in the CPqD GPON network, under Goal 3 of GIGA Project, allowing the achievement of a Fiber-to-the-Building (FTTB) topology with 80km of extension and 128 users served by a single central office. Besides these experimental validations, were simulated computationally SOAs with optimized characteristics as well as systems using remotely pumped erbium-doped fibers, whereas in the latter were reached distances exceeding 100 km.

O surgimento de novos serviços que requerem uma largura de banda cada vez maior, bem como o crescente número de usuários de tais serviços, têm introduzido desafios às empresas operadoras de telecomunicações em sua capacidade de atender a estas demandas sem perda apreciável da qualidade de serviço e mantendo, ainda assim, os custos num nível aceitável pelos usuários. Neste contexto, redes ópticas passivas (PONs) vêm atraindo grande interesse em anos recentes. Na sua variante de longo-alcance, as redes PON permitem uma consolidação do uso dos equipamentos e centrais de serviço requeridos, reduzindo custos operacionais e de instalação. Uma das formas de atingir este maior alcance dá-se por meio da inserção de amplificadores ópticos nas redes de acesso. Neste trabalho, portanto, estudaram-se alguns tipos de amplificadores ópticos e suas possíveis aplicações em redes de acesso, levando a topologias de longo alcance e alta capacidade. Foram realizadas avaliações experimentais de um extensor, baseado em amplificadores ópticos semicondutores (SOAs), na rede GPON do CPqD, sob a Meta 3 do Projeto GIGA, possibilitando a obtenção de uma topologia do tipo Fiber-to-the-Building (FTTB) com 80 km de extensão e 128 usuários atendidos por uma única central de serviço. Além dessas validações experimentais, foram simulados computacionalmente SOAs com características otimizadas bem como sistemas que utilizam fibras dopadas com érbio bombeadas remotamente, sendo que nestes últimos, atingiram-se distâncias superiores a 100 km. / The emergence of new services which require an increasing bandwidth, as well as the growing number of users of such services, have introduced challenges to the network operators in regard to their capacity of supporting these demands with no penalty on the required quality of service, while keeping the costs at an acceptable level for the users. In this context, passive optical networks (PONs) have attracted a great deal of interest in recent years. In the long-reach configuration, PON networks allow for a consolidation of equipament usage, reducing operational and installation costs. One way to achieve this longer reach is by the insertion of optical amplifiers in the access network. Therefore, in our work, we have investigated several optical amplifier configurations, as well as their application in access networks, leading to longreach and high capacity network topologies. Experimental evaluations of an extender, based on semiconductor optical amplifiers, were carried out in the CPqD GPON network, under Goal 3 of GIGA Project, allowing the achievement of a Fiber-to-the-Building (FTTB) topology with 80km of extension and 128 users served by a single central office. Besides these experimental validations, were simulated computationally SOAs with optimized characteristics as well as systems using remotely pumped erbium-doped fibers, whereas in the latter were reached distances exceeding 100 km.

Au cours des dernières décennies, le monde a subi une révolution majeure qui a profondément affecté comment on utilise les réseaux de communication. De nouveaux services et applications ont été apparus, tels que les réseaux sociaux, les jeux en ligne ou le streaming en direct, qui exigent une augmentation constante de la capacité des systèmes optiques. La motivation de ce travail est donc d'étudier la mise en œuvre d'un nouvel amplificateur SOA à très large bande avec une bande passante de plus de 100 nm afin d’étendre la capacité du système. L'utilisation de l'amplification SOA change complètement le paradigme dans la conception d'un système optique puisque toutes les dégradations ajoutées par la SOA doivent être considérées. Ainsi, la recherche d'un modèle analytique ou numérique capable de caractériser la nature non linéaire de ce dispositif est d'abord étudiée. Ensuite, on montre comment un SOA bien conçu peut non seulement amplifier un signal à large bande, mais également surmonter certains des principaux inconvénients du SOA devant EDFA. Finalement, on évalue la capacité de ce nouveau UWB SOA pour les applications d'interconnexion de centres de données avec deux expériences en transmettant jusqu'à 115 Tbps de données dans une liaison à bande passante continue de 100 nm sur 100 km de fibre et en testant la stabilité du système avec cartes de ligne en temps réelle entre deux points de présence (POP) de Facebook déployés dans la région parisienne / Over the last few decades the world has undergone a major revolution that has deeply affected the way we use communication networks. New services and applications have appeared demanding a constant increase of the channel capacity. In this period, optical systems have been upgraded at pair with advanced signal processing techniques which have permitted the increase of the spectral efficiency approaching the system capacity to the fundamental limit. It is because is becoming extremely challenging to keep growing the system capacity by this means. In this work, an orthogonal direction is studied to further increase the fibre capacity: extending the optical bandwidth. With this purpose, the use of semiconductor optical amplifiers (SOA) is investigated to be implemented in future ultra-wideband (UWB) systems. The use of SOA amplification changes completely the paradigm in the design of an optical system since all the impairments added by the SOA must be considered. In this work, we assess the reservoir model, a simple yet powerful model, to analyze numerically the nonlinear regime of the SOA for WDM systems. We also show for the first that the linewidth enhancement factor of an SOA can be estimated with a coherent receiver. Finally, it is also studied how the correlation between channels degrades significantly the performance of the SOA and the inclusion of a decorrelation fibre is investigated. The conception of a UWB system is then studied. We characterize a novel ultra-wideband SOA developed by the French project CALIPSO which presents high gain in a 100-nm optical bandwidth with high output saturation power and 6-8 dB of noise figure. We analyze its nonlinear regime for WDM systems and we show for QPSK and 16 QAM modulation formats that the input saturation power can be overtaken by serveral dBs without important nonlinear penalty. On the other hand, a novel technique is studied to compensate fibre nonlinearities in UWB systems: the multicarrier multiplexing, which tries to exploit the concept of symbol rate optimization. Finally, we assess the capabilities of this novel UWB SOA for data-centre interconnection applications with two experiments transmitting up to 113 Tbps data troughput in a 100-nm continuous bandwidth link over 100 km of fibre and then testings is stability with real-time line cards between two points of presence (POP)of Facebook deployed in the Paris area

Made available in DSpace on 2014-07-29T15:07:08Z (GMT). No. of bitstreams: 1 Dissertacao Alexandre Miranda de Oliveira.pdf: 4426704 bytes, checksum: 904266306eab31523948c4d6634abfe0 (MD5) Previous issue date: 2010-12-15 / This work is to study the crystallization of compounds in the form of post system alumina-yttria-silica prepared by sol-gel mixed methodology and Pechini. Powders (x / 2) Y ² ³ - (X / 2) Al ² O ³ - (1-x) SiO ² (x = 0.1 0.2, 0.3, 0.4 and 0.5 mol) were doped with erbium prepared and characterized. The physical properties of composite SiO ² ¹ YO-, 5 - AlO ¹, 5 were studied by x-ray diffraction, FTIR spectroscopy, thermogravimetry, differential thermal analysis and photoluminescence measurements. It was possible to maintain the amorphous compositions at high temperatures, no crystallization below 900 ° C and the formation of phase Y ² ² O7 Si at 1100 ° C. We obtained a reasonable life time of some compositions treated at 1000 ° C. We observed the emission of green upconversion to excite the samples with high power laser. All synthesized samples exhibit photoluminescence emission and have maximum emission at 1530 nm with a width of ~ 47nm. This broad issue is a desirable property for amplifiers used in systems division multiplexing wavelengths (WDM) and suggests that Er ³ + ions are hosted in the amorphous phase. / Neste trabalho estudo-se a cristalização de compostos na forma de pós do sistema alumina-ítria-sílica preparados pela metodologia mista sol-gel e Pechini. Pós de (x/2) Y²O³-(X/2) Al²O³-(1-x) SiO² (x=0,1 0,2, 0,3, 0,4 e 0,5 em mol) dopados com érbio foram preparados e caracterizados. As propriedades físicas dos composto de SiO²-YO¹,5- AlO¹,5 foram estudadas por difração de raios-x, espectroscopia FTIR, termogravimetria, análise térmica diferencial e medidas de fotoluminescência. Foi possível manter as composições amorfas a altas temperaturas, não houve cristalização abaixo de 900° C e a formação da fase Y²Si²O7 a 1100 °C. Obtivemos um tempo de vida razóavel de algumas composições tratadas a 1000°C. Observamos a emissão verde de upconversion ao excitar as amostras com laser de alta potência. Todas as amostras sintetizadas apresentam emissão fotoluminescente e possuem máximo de emissão em 1530 nm com largura a meia altura de ~47nm. Essa emissão larga é uma propriedade desejável para amplificadores usados em sistemas de multiplexação por divisão de comprimentos de onda (WDM) e sugere que os íons Er³+ estão hospedados na fase amorfa.