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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Métamatériaux pour l’infrarouge et applications / Metamaterials for the infrared and applications

Ghasemi, Rasta 12 November 2012 (has links)
Les métamatériaux sont des composites artificiels présentant des propriétés électromagnétiques qu’on ne trouve pas dans la nature. Malgré des développements spectaculaires durant la dernière décennie, le potentiel de ces structures aux longueurs d’ondes optique n’est pas encore clairement défini en raison de problèmes technologiques et de contraintes physiques telles que les pertes dans les métaux entrant dans la composition des métamatériaux. Dans notre thèse, nous montrons que les métamatériaux ont des propriétés très favorables dans le contexte de l’optique intégrée dans le proche infrarouge. Nous avons développé une stratégie pour incorporer des métamatériaux dans des circuits photoniques qui n’absorbent que très peu d’énergie. Pour cela, nous ne faisons pas directement agir l’ensemble du mode guidé avec les métamatériaux, mais seulement une composante évanescente à l’extérieur du guide. Pour réaliser un tel adaptateur ou d’autres fonctionnalités, il importe de déterminer quelle géométrie de métamatériaux est la plus favorable aux applications infrarouges. Nous proposons d’utiliser des structures à base de fils d’or empilés couche sur couche. A l’aide de simulations numériques et d’expériences en espace libre, nous montrons qu’il est possible d’obtenir toute une gamme de réponses optiques en contrôlant le couplage entre les différents niveaux de fils, c'est-à-dire en ajustant la distance entre les fils ainsi que leur alignement. En particulier, nous avons réussi à contrôler séparément la réponse électrique et magnétique de nos structures, ce qui offre une flexibilité de conception qui ne se rencontre pas dans les métamatériaux proposés jusqu’à présent. / Metamaterials are artificial composites with electromagnetic properties not found in nature. Although the development of metamaterials has experienced a tremendous growth over the past few years, their potential at optical wavelengths is not clearly established due to technological and physical constraints such as high material losses in this spectral range. Here we show that metamaterials have a great potential in the context of integrated optics in the near infrared. We developed a strategy to incorporate metamaterials in photonic circuits with minimal absorption losses. Our approach relies on making the guided modes interact with the metamaterials only through the evanescent tail outside the waveguide. To achieve such an adaptor and other functionalities, it is important to know what is the best geometry for near-infrared applications. We propose to use metamaterials based on multi-layers of Au cut wires. With numerical simulations and experiments, we show that it is possible to create a wide range of optical properties by controlling the interaction between the wires, i.e. by adjusting the distance between the wires and their alignment. In particular we were able to demonstrate
192

Desenvolvimento de processo litográfico tri-dimensional para aplicação em microóptica integrada. / Development of three-dimensional lithographic process for application in integrated micro-optics.

Catelli, Ricardo Tardelli 21 July 2010 (has links)
O presente trabalho tem como objetivo desenvolver um processo de fabricação de elementos micro-ópticos utilizando-se litografia por feixe de elétrons, empregando o resiste SU-8, negativo e amplificado quimicamente, sobre substrato de Si. Para tanto, é realizado o estudo dos parâmetros do efeito de proximidade a, b e h para se modelar e controlar os efeitos do espalhamento dos elétrons no resiste e no substrato, e se altera o processamento convencional do SU-8 para se obter um processo com baixo contraste. A determinação dos parâmetros do efeito de proximidade para o sistema de escrita direta e amostra SU-8 / Si é feita experimentalmente e por simulação de Monte Carlo. Particularmente, verifica-se a dependência dos mesmos com a profundidade do resiste. Primeiramente utilizando o software PROXY, obtêm-se a, b e h da observação de padrões de teste revelados. Chega-se a 4m para o parâmetro () que mede o retroespalhamento dos elétrons pelo substrato e 0,7 para a relação (h) entre a intensidade destes com aquela dos elétrons diretamente espalhados pelo resiste (alcance dado por a). Ainda, com esses dados, estima-se o diâmetro do feixe do microscópio eletrônico de varredura a partir da equação de aproximação de espalhamento direto para pequenos ângulos (a = 128nm na superfície do resiste) e se determina a resolução lateral do processo (a = 800nm na interface resiste/ substrato, para um filme de 2,4m). Em seguida, usa-se o software CASINO para se calcular os parâmetros de proximidade a partir da curva de densidade de energia dissipada no resiste obtida pela simulação da trajetória de espalhamento dos elétrons. Confrontam-se, finalmente, os valores obtidos pelos dois métodos. Em relação ao processamento do resiste SU-8, são determinadas as condições experimentais para a fabricação de estruturas tridimensionais por litografia de feixe de elétrons. Especificamente, busca-se desenvolver um processo com características (espessura, contraste, sensibilidade e rugosidade) adequadas para a fabricação de micro-dispositivos ópticos. Inicia-se com o levantamento das curvas de contraste e da sensibilidade do SU-8 para determinadas temperaturas de aquecimento pós-exposição. Obtém-se contraste abaixo de 1 para aquecimento pós-exposição abaixo da temperatura de transição vítrea do resiste, mantendo-se sensibilidade elevada (2C/cm2). Em seguida, mede-se a rugosidade da superfície do filme revelado para diferentes doses de exposição. Para finalizar, submete-se a amostra a um processo de cura e escoamento térmico, para melhorar a dureza e a rugosidade do resiste a ser utilizado como dispositivo final Consegue-se um valor de rugosidade (40nm) inferior a 20 vezes o comprimento de onda de diodo laser de eletrônica de consumo. Por fim, é produzido um dispositivo com perfil discretizado em 16 níveis como prova de conceito. / This work aims at developing an electron-beam lithography process for the fabrication of microoptical elements using the negative tone chemically amplified resist SU-8 on Si substrate. A study of the proximity effect parameters a, b and h is carried out to model and control the electron scattering both in the resist and in the substrate, and the SU-8 standard processing conditions are changed to achieve a low contrast process. The determination of the SU-8 / Si proximity effect parameters and its dependence with resist depth is done employing an experimental method and through Monte Carlo simulations. First, a, b and h are obtained comparing exposed patterns calculated by the software PROXY. b, the parameter which measures the backscattering of the electrons by the substrate, is equal to 4m and the value of h, the ratio of the dose contribution of backscattered electrons to that of the forward scattered (related to a), is 0.7. The extrapolation of exposed patterns data is used to estimate the scanning electron microscope beam diameter through the equation for low angle scattering (a = 128nm at the resist surface) and the lateral resolution of the process is determined (a = 800nm at the resist/ substrate interface, for a 2.4m film). With aid of the software CASINO, Monte Carlo simulations of the scattering trajectories of electrons in substrate and resist materials are calculated, recording the energy that they dissipate through collisions along their path. The results obtained representing the profile of the energy dissipated in the resist are used to determine the proximity effect parameters. The experimental method results are compared to that obtained by simulation. Regarding the SU-8 processing, the process parameters for the fabrication of three-dimensional structures by electron-beam lithography are determined. The process is designed to have specifications (thickness, contrast, sensitivity and surface roughness) suitable for microoptical elements fabrication. It begins with the determination of the SU-8 contrast curve and its sensitivity for specific post-exposure bake temperatures. A below the unit contrast process with high sensitivity (2C/cm2) is achieved postannealing the sample below the resist glass transition temperature. The film surface roughness is measured after resist development for different exposure doses, and a controlled hardbake (cure) and reflow is carried to enhance both the mechanical properties and the surface roughness of the structures that will remain as part of the final device. A RMS roughness of 40nm, lower than 20 times the wavelength of consumer electronics laser diode, is obtained. The electron-beam process designed is applied to the fabrication of a microelement with a 16-level profile discretization.
193

Etude de la réalisation d'un isolateur optique intégré sur verre / Study of the realization of a glass-integrated optical isolator

Garayt, Jean-Philippe 31 October 2017 (has links)
L’essor des télécommunications par fibre optique nécessite l’insertion en sortie des lasers d’un isolateur optique intégré protégeant celui-ci des réflexions qui le déstabilisent. Ce composant existe à l’heure actuelle sous forme massive, mais son intégration sur la même plaquette que le laser pose problème du fait de la difficulté à intégrer les bons matériaux magnétooptiques sur les substrats usuels de l’optique guidée. Dans cette perspective, l’intégration de nanoparticules magnétiques dans un sol-gel déposé sur les guides optiques est une voie prometteuse, développée par le laboratoire Hubert Curien. Cette thèse a eu pour but d’étudier de manière plus systématique le composant non-réciproque qui entre dans la fabrication des isolateurs à conversion de mode, à savoir le rotateur non-réciproque. Deux études poussées, l’une théorique, l’autre expérimentale, recoupées entre elles par des modèles numériques, ont été mises en oeuvre au cours des années de cette thèse. L’étude théorique a permis de tenir compte tous les paramètres ayant une influence sur l’état de polarisation de la lumière dans un guide magnétooptique, y compris les dichroïsmes souvent négligés. L’étude pratique, à partir d’échantillons sur verre réalisés en collaboration avec l’IMEP-LAHC et le laboratoire PHENIX, a abouti à une caractérisation quasi complète des effets magnétooptiques — longitudinaux et transverses — dans les guides et de l’influence des paramètres de fabrication sur ceux-ci. Au final, ces résultats nous ont donné une compréhension plus complète du fonctionnement des guides magnétooptiques, et nous ont permis de prédire les paramètres optimaux qu’il faudra mettre afin de fabriquer, dans un futur proche, l’isolateur complet sur une seule plaque de verre / The development of optical-fiber telecommunications requires the insertion of optical isolator between lasers and fibers, in order to protect them against perturbating reflexions. This component is currently inserted in a bulk form, but the goal is to integrate it on the same wafer than the laser; nevertheless, this is problematic due to the difficulty to integrate good magnetooptical materials on usual substrates as glass or silicon. One of the promising way to achieve this, developped by the Laboratoire Hubert Curien, is the embedding of magnetic nanoparticles into a sol-gel matrix deposited above the optical guides. This thesis aimed at studying more deeply the main non-reciprocal component of integrated mode conversion optical isolators: the non-reciprocal rotator. A theorical and a practical study have both been performed, with numerical simulations to confront them. The theorical study aimed at describing the evolution of propagation in magnetooptical waveguides with respect to all effects, even absorption and dichroïsm. Then a practical study was performed on glass samples engineered in collaboration with IMEP-LAHC and the PHENIX laboratory, and lead to a full measurement of longitudinal and transverse magnetooptical effects, and their evolution related to the fabrication parameters of the samples. Finally, these results gave us a comprehensive view of how magnetooptical waveguides behave, and we were able to predict the good parameters to choose in order to construct, in a close future, a glass-integrated optical isolator
194

Lasers inp sur circuits silicium pour applications en telecommunications / Hybrid III-V on silicon lasers for telecommunication applications

Lamponi, Marco 15 March 2012 (has links)
La photonique du silicium a connu un développent massif pendant les dix derniers années. Presque toutes les briques technologiques de base ont été réalisées et ont démontrées des performances remarquables. Cependant, le manque d’une source laser intégrée en silicium a conduit les chercheurs à développer de composants basés sur l’intégration entre le silicium et les matériaux III-V.Dans cette thèse je décris la conception, la fabrication et la caractérisation des lasers hybrides III-V sur silicium basés sur cette intégration. Je propose un coupleur adiabatique qui permet de transférer intégralement le mode optique du guide silicium au guide III-V. Le guide actif III-V au centre du composant fourni le gain optique et les coupleurs, des deux cotés, assurent le transfert de la lumière dans les guides silicium.Les lasers mono longueur d’onde sont des éléments fondamentaux des communications optiques. Je décris les différentes solutions permettant d’obtenir un laser mono-longueur d’onde hybride III-V sur silicium. Des lasers mono longueur d’onde ont été fabriqués et caractérisés. Ils démontrent un seuil de 21 mA, une puissance de sortie qui dépasse 10 mW et une accordabilité de 45 nm. Ces composants représentent la première démonstration d’un laser accordable hybride III-V sur silicium. / Silicon photonics knew an impressive development in the last ten years. Almost all the fundamental building blocks have been demonstrated and reveal competitive performances. However, the lack of an efficient silicon integrated laser source has led the researchers to develop heterogeneous integration of III-V materials on silicon.In this thesis I describe the design, the fabrication and the performances of these hybrid III-V on silicon lasers. I propose the use of an adiabatic coupler that totally transfers the optical mode between the III-V and the silicon waveguides. The active waveguide on III-V materials at the center of the device provides the optical gain, while, on both side, adiabatic couplers allow a loss-less transfer of the optical mode to the silicon waveguide. Single wavelength emitting lasers are fundamental elements for high bandwidth optical links. I review all the effective solutions enabling single waveguide hybrid III-V on SOI lasers. DBR, microring based, DFB and AWG laser solutions were analysed. Single wavelength operating lasers have been fabricated and characterized. A laser threshold of only 21 mA, an output power of more than 10 mW and tunability over 45 nm with a SMSR of 45 dB have been measured. These devices represent the first demonstration of a monolithically integrated hybrid III-V/Si tunable laser made by wafer bonding technique.
195

Multiplexed Optofluidics for Single-Molecule Analysis

Stott, Matthew Alan 01 April 2018 (has links)
The rapid development of optofluidics, the combination of microfluidics and integrated optics, since its formal conception in the early 2000's has aided in the advance of single-molecule analysis. The optofluidic platform discussed in this dissertation is called the liquid core anti-resonant reflecting optical waveguide (LC-ARROW). This platform uses ARROW waveguides to orthogonally intersect a liquid core waveguide with solid core rib waveguides for the excitation of specifically labeled molecules and collection of fluorescence signal. Since conception, the LC-ARROW platform has demonstrated its effectiveness as a lab-on-a-chip fluorescence biosensor. However, until the addition of optical multiplexing excitation waveguides, the platform lacked a critical functionality for use in rapid disease diagnostics, namely the ability to simultaneously detect different types of molecules and particles. In disease diagnostics, the ability to multiplex, detect and identify multiple biomarkers simultaneously is paramount for a sensor to be used as a rapid diagnostic system. This work brings optofluidic multiplexing to the sensor through the implementation of three specific designs: (1) the Y-splitter was the first multi-spot excitation design implemented on the platform, although it did not have the ability to multiplex it served as a critical stepping stone and showed that multi-spot excitation could improve the signal-to-noise ratio of the platform by ~50,000 times; (2) a multimode interference (MMI) waveguide which took the multi-spot idea and then demonstrated spectral multiplexing capable of correctly identifying multiple diverse biomarkers simultaneously; and, (3) a Triple-Core design which incorporates excitation and collection along multiple liquid cores, enabling spatial multiplexing which increases the number of individual molecules to be identified concurrently with the MMI waveguide excitation. In addition to describing the development of optical multiplexing, this dissertation includes an investigation of another LC-ARROW based design that enables 2D bioparticle trapping, the Anti-Brownian Electrokinetic (ABEL) trap. This design demonstrates two-dimensional compensation of a particle's Brownian motion in solution. The capability to maintain a molecule suspended in solution over time enables the ability to gain a deeper understanding of cellular function and therapies based on molecular functions.
196

Fabrication and characterization of thermo-plasmonic routers for telecom applications

Hassan, Karim 12 July 2013 (has links) (PDF)
The Dielectric Loaded Surface Plasmon Polariton Waveguides (DLSPPWs) have recently emerged as a possible solution to carry both optical and electrical signals on- chip. However, in the particular context of optical interconnects, advanced functionalities such as filtering, switching, and routing are required in order to replace in the future the equivalent electronic components which are too much power consumer and also to reduce their footprints. After presenting the interest and limitation of the leakage radiation microscopy method used all along this work, we show several active devices using thermo-sensitive polymers as the dielectric load driven electrically by Joule heating. Then we demonstrate the feasibility of all-optical systems by either doping the dielectric with metallic nanoparticles or by plasmo-thermal eect of a second plasmonic mode providing a localized heating of controlled shape. The dynamic activation of our thermo- optical devices is performed using a homemade fiber-to-fiber setup which allows us to investigate the response time of a plasmo-thermal heating as well as true datacom transmission. Some improvements of the original DLSPPWs performances are proposed by adding a metallic wall on one side of the polymer ridge. This system can act as a compact and athermal polarization converter
197

Ge/SiGe quantum well devices for light modulation, detection, and emission

Chaisakul, Papichaya 23 October 2012 (has links) (PDF)
This PhD thesis is devoted to study electro-optic properties of Gemanium/Silicon-Germanium (Ge/SiGe) multiple quantum wells (MQWs) for light modulation, detection, and emission on Si platform. It reports the first development of high speed, low energy Ge/SiGe electro-absorption modulator in a waveguide configuration based on the quantum-confined Stark effect (QCSE), demonstrates the first Ge/SiGe photodiode with high speed performance compatible with 40 Gb/s data transmission, and realizes the first Ge/SiGe light emitting diode based on Ge direct gap transition at room temperature. Extensive DC and RF measurements were performed on each tested prototype, which was realized using the same epitaxial growth and fabrication process. Simple theoretical models were employed to describe experimental properties of the Ge/SiGe MQWs. The studies show that Ge/SiGe MQWs could potentially be employed as a new photonics platform for the development of a high speed optical link fully compatible with silicon technology.
198

Calibrages et études applicatives de la technologie SWIFTS / Calibrations and application studies of the SWIFTS technology

Thomas, Fabrice 30 November 2015 (has links)
SWIFTS (Stationary Wave Integrated Fourier Transform Spectrometer) est une nouvelle technologie innovante de spectrométrie qui permet une réduction radicale de la taille des spectromètres à Transformée de Fourier, tout en conservant, et même en améliorant leurs performances. Grâce aux avancées de l'optique intégrée et des nanotechnologies, SWIFTS repose sur une méthode de détection optique originale, sans aucune partie mobile, où des nanoplots métalliques échantillonnent directement le champ évanescent d'une onde stationnaire dans un guide d'onde.Dans cette thèse, nous proposons de présenter le cheminement complet qui a mené, en partant du concept original, au développement puis à la mise en pratique de la technologie SWIFTS. Le document illustre notamment les caractérisations optiques, les choix technologiques et les optimisations entrepris pour la réalisation de spectromètres fonctionnels dans le domaine visible et proche-infrarouge. Des procédures de calibrages novatrices et complémentaires, basées sur du multiplexage fréquentiel et sur de l'interférométrie à faible cohérence temporelle, ont été développées pour déterminer avec précision les différentes irrégularités de fabrication et de comportement de l'appareil complètement intégré. Les spectromètres calibrés permettent à présent d'aborder des applications diverses en industrie et en recherche, de la caractérisation hautes performances de lasers, à l'interrogation de capteurs fibrés à réseaux de Bragg, aux techniques de spectrométries Raman et LIBS, et de tomographie optique OCT, jusqu'aux sciences de l'Univers (géophysique, astrophysique).SWIFTS est une innovation de rupture qui, de part sa miniaturisation obtenue sans compromis avec de hautes performances d'analyse spectrale, a la capacité de faire passer la spectrométrie du stade de la mesure complexe en laboratoire à celle d'un simple composant intégré pour des applications exigeantes. / SWIFTS (Stationary Wave Integrated Fourier Transform Spectrometer) is a new innovative technology of spectrometry that allows a drastic reduction of the size of Fourier transform spectrometers, while maintaining, and even improving their performance. With advances in integrated optics and nanotechnology, SWIFTS is based on an original method of optical detection, without any moving part, where metallic nanodots directly sample the evanescent field of a standing wave in a waveguide.In this thesis, we propose to present the complete process that led, starting from the original concept, to the development and the applications of the technology. The document illustrates the optical characterizations, the technological choices and the optimizations made for the realization of functional spectrometers in the visible and near-infrared range. Innovative and complementary procedures of calibrations, based on frequency multiplexing and low coherence interferometry, have been developed to accurately determine the various irregularities of the manufacturing and of the behavior of the integrated device. The calibrated spectrometers allow to address various applications in industry and research, such as high performance characterization of lasers, interrogation of fiber Bragg gratings sensors, Raman and LIBS spectrometry, optical coherence tomography OCT, and sciences of the Universe (geophysics, astrophysics).SWIFTS is a breakthrough innovation in spectrometry, without trade-off between miniaturization and high performance, that opens the way for product development based on the most demanding applications currently performed in research laboratories.
199

Desenvolvimento de processo litográfico tri-dimensional para aplicação em microóptica integrada. / Development of three-dimensional lithographic process for application in integrated micro-optics.

Ricardo Tardelli Catelli 21 July 2010 (has links)
O presente trabalho tem como objetivo desenvolver um processo de fabricação de elementos micro-ópticos utilizando-se litografia por feixe de elétrons, empregando o resiste SU-8, negativo e amplificado quimicamente, sobre substrato de Si. Para tanto, é realizado o estudo dos parâmetros do efeito de proximidade a, b e h para se modelar e controlar os efeitos do espalhamento dos elétrons no resiste e no substrato, e se altera o processamento convencional do SU-8 para se obter um processo com baixo contraste. A determinação dos parâmetros do efeito de proximidade para o sistema de escrita direta e amostra SU-8 / Si é feita experimentalmente e por simulação de Monte Carlo. Particularmente, verifica-se a dependência dos mesmos com a profundidade do resiste. Primeiramente utilizando o software PROXY, obtêm-se a, b e h da observação de padrões de teste revelados. Chega-se a 4m para o parâmetro () que mede o retroespalhamento dos elétrons pelo substrato e 0,7 para a relação (h) entre a intensidade destes com aquela dos elétrons diretamente espalhados pelo resiste (alcance dado por a). Ainda, com esses dados, estima-se o diâmetro do feixe do microscópio eletrônico de varredura a partir da equação de aproximação de espalhamento direto para pequenos ângulos (a = 128nm na superfície do resiste) e se determina a resolução lateral do processo (a = 800nm na interface resiste/ substrato, para um filme de 2,4m). Em seguida, usa-se o software CASINO para se calcular os parâmetros de proximidade a partir da curva de densidade de energia dissipada no resiste obtida pela simulação da trajetória de espalhamento dos elétrons. Confrontam-se, finalmente, os valores obtidos pelos dois métodos. Em relação ao processamento do resiste SU-8, são determinadas as condições experimentais para a fabricação de estruturas tridimensionais por litografia de feixe de elétrons. Especificamente, busca-se desenvolver um processo com características (espessura, contraste, sensibilidade e rugosidade) adequadas para a fabricação de micro-dispositivos ópticos. Inicia-se com o levantamento das curvas de contraste e da sensibilidade do SU-8 para determinadas temperaturas de aquecimento pós-exposição. Obtém-se contraste abaixo de 1 para aquecimento pós-exposição abaixo da temperatura de transição vítrea do resiste, mantendo-se sensibilidade elevada (2C/cm2). Em seguida, mede-se a rugosidade da superfície do filme revelado para diferentes doses de exposição. Para finalizar, submete-se a amostra a um processo de cura e escoamento térmico, para melhorar a dureza e a rugosidade do resiste a ser utilizado como dispositivo final Consegue-se um valor de rugosidade (40nm) inferior a 20 vezes o comprimento de onda de diodo laser de eletrônica de consumo. Por fim, é produzido um dispositivo com perfil discretizado em 16 níveis como prova de conceito. / This work aims at developing an electron-beam lithography process for the fabrication of microoptical elements using the negative tone chemically amplified resist SU-8 on Si substrate. A study of the proximity effect parameters a, b and h is carried out to model and control the electron scattering both in the resist and in the substrate, and the SU-8 standard processing conditions are changed to achieve a low contrast process. The determination of the SU-8 / Si proximity effect parameters and its dependence with resist depth is done employing an experimental method and through Monte Carlo simulations. First, a, b and h are obtained comparing exposed patterns calculated by the software PROXY. b, the parameter which measures the backscattering of the electrons by the substrate, is equal to 4m and the value of h, the ratio of the dose contribution of backscattered electrons to that of the forward scattered (related to a), is 0.7. The extrapolation of exposed patterns data is used to estimate the scanning electron microscope beam diameter through the equation for low angle scattering (a = 128nm at the resist surface) and the lateral resolution of the process is determined (a = 800nm at the resist/ substrate interface, for a 2.4m film). With aid of the software CASINO, Monte Carlo simulations of the scattering trajectories of electrons in substrate and resist materials are calculated, recording the energy that they dissipate through collisions along their path. The results obtained representing the profile of the energy dissipated in the resist are used to determine the proximity effect parameters. The experimental method results are compared to that obtained by simulation. Regarding the SU-8 processing, the process parameters for the fabrication of three-dimensional structures by electron-beam lithography are determined. The process is designed to have specifications (thickness, contrast, sensitivity and surface roughness) suitable for microoptical elements fabrication. It begins with the determination of the SU-8 contrast curve and its sensitivity for specific post-exposure bake temperatures. A below the unit contrast process with high sensitivity (2C/cm2) is achieved postannealing the sample below the resist glass transition temperature. The film surface roughness is measured after resist development for different exposure doses, and a controlled hardbake (cure) and reflow is carried to enhance both the mechanical properties and the surface roughness of the structures that will remain as part of the final device. A RMS roughness of 40nm, lower than 20 times the wavelength of consumer electronics laser diode, is obtained. The electron-beam process designed is applied to the fabrication of a microelement with a 16-level profile discretization.
200

Fabrication and characterization of thermo-plasmonic routers for telecom applications / Fabrication et caractérisation de routeurs thermo-plasmoniques pour les applications telecom

Hassan, Karim 12 July 2013 (has links)
Les guides d’ondes plasmoniques à rubans dielectriques (DLSPPW) sont récemment apparus comme une des solutions possible pour le transport de signaux optiques et électriques sur puce. Néanmoins, dans le contexte particulier des interconnections optiques, des fonctionalitées avancées telles que filtrage, commutation, et routage sont nécessaires afin de remplacer dans le futur les composants electroniques équivalents trop gourmands en énergie et aussi réduire leur empreinte. Après une présentation des intérêts et limitations de la technique de micro- scopie à fuite radiative, nous montrons plusieurs composants actifs utilisant pour diélectrique des polymères thermo-sensibles controlés électriquement par eet Joule. Par la suite nous démontrons la faisabilité de systèmes tout optique que ce soit par dopage du polymère par des nanoparticules metalliques ou par eet thermo-plasmonique d’un second mode plasmon permettant un échauement localisé de forme choisie. L’activation dynamique de nos composants thermo-optiques est réalisée grâce à un montage fibre-à-fibre créé spécialement nous permettant d’investiguer le temps de réponse d’un chauage plasmonique ainsi que la transmission de signal télécom. Des améliorations de performances du concept DLSPPW original sont proposées par l’ajout d’un mur métallique sur le côté du ruban de polymère. Ce système peut alors fonctionner comme un convertisseur de polarisation compacte et athermique / The Dielectric Loaded Surface Plasmon Polariton Waveguides (DLSPPWs) have recently emerged as a possible solution to carry both optical and electrical signals on- chip. However, in the particular context of optical interconnects, advanced functionalities such as filtering, switching, and routing are required in order to replace in the future the equivalent electronic components which are too much power consumer and also to reduce their footprints. After presenting the interest and limitation of the leakage radiation microscopy method used all along this work, we show several active devices using thermo-sensitive polymers as the dielectric load driven electrically by Joule heating. Then we demonstrate the feasibility of all-optical systems by either doping the dielectric with metallic nanoparticles or by plasmo-thermal eect of a second plasmonic mode providing a localized heating of controlled shape. The dynamic activation of our thermo- optical devices is performed using a homemade fiber-to-fiber setup which allows us to investigate the response time of a plasmo-thermal heating as well as true datacom transmission. Some improvements of the original DLSPPWs performances are proposed by adding a metallic wall on one side of the polymer ridge. This system can act as a compact and athermal polarization converter

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