Dissertations / Theses on the topic 'Mach-Zehnder modulators'
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Nguyen, Giang Thach, and thach nguyen@rmit edu au. "Efficient Resonantly Enhanced Mach-Zehnder Optical Modulator on Lithium Niobate." RMIT University. Electrical and Computer Engineering, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20070118.162330.
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Photonic links have been proposed to transport radio frequency (RF) signals over optical fiber. External optical modulation is commonly used in high performance RF-photonic links. The practical use of optical fiber to transport RF signals is still limited due to high RF signal loss. In order to reduce the RF signal loss, highly efficient modulators are needed. For many applications, modulators with broad bandwidths are required. However, there are applications that require only a narrow bandwidth. For these narrow-band applications, the modulation efficiency can be improved through the resonant enhancement technique at the expense of reduced bandwidth. The aim of this thesis is to investigate highly efficient Mach-Zehnder optical modulators (MZMs) on Lithium Niobate (LiNbO3) with resonant enhancement techniques for narrow-band RF-photonic applications. This work focuses in particular on analyzing the factors that affect the modulation efficiency through resonant enhancement so that the modulator electrode structure can be optimized for maximum modulation efficiency. A parameter study of the effects of the electrode characteristics on the modulation efficiency of resonantly enhanced modulators (RE-MZM) is provided. From this study, optimum design objectives are identified. Numerical optimization is employed to explore the design trade-offs so that optimal configurations can be found. A sensitivity analysis is carried out to assess the performance of optimal RE-MZMs with respect to the variations of fabrication conditions. The results of these investigations indicate that the RE-MZM with a large electrode gap is the optimal design since it provides high modulation efficiency although the inherent switching voltage is high, and is the most tolerant to the fabrication fluctuations. A highly efficient RE-MZM on X-cut LiNbO3 is practically demonstrated with the resonant enhancement factor of 5 dB when comparing to the unenhanced modulator with the same electrode structure and effective switching voltage of 2 V at 1.8 GHz. The performance of the RF-photonic link using the fabr icated RE-MZM is evaluated. Optimization of RE-MZMs for operating at millimeter-wave frequencies is also reported. Factors that limit the modulation efficiency of an RE-MZM at millimeter-wave frequencies are identified. Novel resonant structures that can overcome these limitations are proposed. Preliminary designs indicate that greatly improved modulation efficiency could be expected.
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Peng, Geng 1968. "The waveguide design for wide band Ti : LiNbO3 Mach-Zehnder intensity modulators /." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=20798.
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In this thesis, the waveguide design characterization for wide-band Ti : LiNbO3 Mach-Zehnder electro-optical interferometric intensity modulators (Z-cut substrate) has been performed using a combination of the effective index method and the 2D finite-difference vectorial beam propation method (FD-VBPM). For the passive aspect of the device, to minimize the propagation loss, the coherent coupling effect of radiation modes has been studied as well as the effectiveness of a cosine-generated Y-branch and a notched Y-branch in comparison with the conventional sharp-bend Y-branch. By making use of the coherent coupling effect on a notched Y-branch structure, a propagation loss figure of 0.145 dB/cm has been achieved. For the active aspect including the electro-optical effect, the minimum seperation of the two waveguide arms in order to achieve an extinction ratio above 20 dB has been decided and the corresponding modulation curve obtained. The best achieved extinction ratio is 21.8 dB with a 15 mum seperation between the inner edges of two branching arms for a 80 GHz electrode design. Two different electrode structures have been design-tested and compared. Tolerance of the alignment between the optical waveguides and the electrodes has also been determined.
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Peng, Geng. "The waveguide design for wide band Ti:LiNbO¦3 Mach-Zehnder intensity modulators." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0004/MQ44101.pdf.
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Ferguson, Anna. "The design and characterisation of GaAs/AlGaAs waveguides and Mach-Zehnder modulators." Thesis, University of Leeds, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410758.
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Jones, Warren Richard. "Investigation of Mach-Zehnder modulators in the context of fibre supported mm-wave communications." Thesis, Bangor University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261414.
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Abel, Stefan. "Dispositifs électro-optiques à base de titanate de baryum épitaxié sur silicium pour la photonique intégrée." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENT004/document.
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En premier lieu, des couches minces épitaxiales ont été obtenues sur des substrats de silicium grâce à l’utilisation de l’épitaxie par jets moléculaire et de couches tampons de titanate de strontium SrTiO3. Une technique de croissance par co-déposition a été développée de manière à obtenir un rapport Ba:Ti proche de la stoechiométrie, et ce afin d’éviter la formation de défauts cristallins dans la couche de BaTiO3. Le matériau déposé cristallise dans une structure de symétrie quadratique, ce qui est unpré-requis pour l’obtention de propriétés électro-optiques. De plus, selon les conditions de croissance, l’axe c de la maille élémentaire quadratique a pu être ajusté de manière à être aligné parallèlement ou perpendiculairement à la surface du substrat. L’utilisation d’une mince couche tampon de nucléation a également permis de croitre des films mincesBaTiO3 épitaxiées par pulvérisation, technique largement répandue en milieu industriel.Un coefficient de Pockels élevé a par la suite été obtenu sur de tellescouches épitaxiées. La valeur mesurée de 148pmV est clairement supérieure aux valeurs admises dans la littérature pour d’autres matériaux nonlinéairestels que le niobate de lithium, pour lequel un coefficient de31pmV est rapporté. La méthode de caractérisation électro-optique développée à cette occasion révèle également le caractère ferroélectrique des couches de BaTiO3, observé pour la première fois dans de tels matériaux épitaxiés sur silicium.Finalement, ces couches minces électro-optiquement actives ont été intégrées dans des dispositifs photoniques sur silicium. Dans cette optique,une structure de guide d’onde à fente a été utilisée en insérant 50nm deBaTiO3 entre deux couches de silicium. Dans ce type de structure, le confine mentoptique est 5 fois supérieur à celui obtenu pour des guides d’onde en silicium avec une gaine à base de BaTiO3. Des guides d’ondes rectilignesont tout d’abord été fabriqués, pour lesquels des pertes optiques del’ordre de 50−100 dB/cm ont été mesurées. Par la suite, des composants passifs fonctionnels ont été fabriqués, tels que des interféromètres typeMach-Zehnder, des résonateurs circulaires et des coupleurs. Finalement,la fonctionnalité de composants actifs a été démontrée pour la première fois, en se basant notamment sur des résonateurs ayant un facteur de qualité Q d’environ 5000, et pour lequel la résonance varie en fonction du champ électrique transverse. L’origine physique de cette variation n’a cependant pas pu être expliquée sur la seule base de l’effet Pockels. Cette thèse démontre que l’utilisation de nouveaux matériaux électro optiquement actifs au coeur de dispositifs photoniques sur silicium créede nouvelles opportunités pour la conception et l’ingénierie de circuitsphotoniques. L’intégration d’oxydes tels que barium titanate permet d’envisager de nouveaux concepts de dispositifs pour ajuster, moduler ou commuter la lumière au sein de circuits photoniques denses. De nouveaux défis et perspectives s’ouvrent également aux scientifiques pour modifier artificiellement les propriétés électro-optiques de ces matériaux, que ce soit par contrainte, dopage ou par l’ingénierie de multicouches. De telles avancées pourront sans aucun doute fortement améliorer les performances des dispositifsA novel concept of utilizing electro-optical active oxides in silicon photonic devices is developed and realized in the frame of this thesis. The integration of such oxides extends the silicon photonics platform by non-linear materials, which can be used for ultra-fast switching or low-power tuning applications. Barium titanate is used as active material as it shows one of the strongest Pockels coefficients among all oxides. Three major goals are achieved throughout this work: First, thin films of BaTiO3 are epitaxially grown on silicon substrates via molecular beam epitaxy (MBE) using thin SrTiO3 buffer layers. A shuttered co-deposition growth technique is developed in order to minimize the formation of defects in the BaTiO3 films by achieving a 1:1 stoichiometry between barium and titanium. The layers show a tetragonal symmetry and are therefore well-suited for electro-optical applications. The orientation of the long c -axis of the BaTiO3 crystal can be tuned to point perpendicular or parallel to the film surface, depending on the growth conditions. In addition, thin MBE-grown seed layers are combined with rf-sputter deposition. With this hybrid growth approach, rather thick ( > 100 nm), epitaxial BaTiO3 layers on silicon substrates are obtained with a commercially available, wide spread deposition technique. As a second goal, a strong Pockels coefficient of reff = 148 pm/V is determined in the epitaxial BaTiO3 films. This first experimental result on the electro-optical activity of BaTiO3 layers on silicon shows a clear enhancement compared to alternative non-linear materials such as lithium niobate with reff = 31 pm/V. By means of the electro-optical characterization method, also the presence of ferroelectricity in the films is demonstrated. Third, the electro-optical active BaTiO3 layers are embedded into silicon photonic devices. For this purpose, a horizontal slot-waveguide structure with a ~50 nm-thick BaTiO3 film sandwiched between two silicon layers is designed. With this design, the optical confinement in the active BaTiO3 layer is enhanced by a factor of 5 compared to Si-waveguide structures with a standard cross section and BaTiO3 as cladding. Straight BaTiO3 slot-waveguides with propagation losses of 50 − 100 dB/cm as well as functional passive devices such as Mach-Zehnder-interferometers, couplers, and ring resonators are experimentally realized. Additionally, first active ring resonators with Q-factors of Q~5000 are fabricated. The physical origin of the observed resonance shift as a function of the applied bias voltage, however, can not be conclusively clarified in the present work. The combination of high-quality, functional BaTiO3 layers with silicon photonic devices as demonstrated in this thesis offers new opportunities by extending the design palette for engineering photonic circuits with the class of electro-opticalactive materials. The integration of oxides such as BaTiO3 enables novel device concepts for tuning, switching, and modulating light in extremely dense photonic circuits. The integration also opens exciting challenges for material scientists to tailor the electro-optical properties of those oxides by strain engineering or fabrication of superlattice structures, which could ultimately lead to another boost of their electro-optical properties
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Giuglea, Alexandru, Guido Belfiore, Mahdi Khafaji, Ronny Henker, Despoina Petousi, Georg Winzer, Lars Zimmermann, and Frank Ellinger. "Comparison of Segmented and Traveling-Wave Electro-Optical Transmitters Based on Silicon Photonics Mach-Zehnder Modulators." Institute of Electrical and Electronics Engineers (IEEE), 2018. https://tud.qucosa.de/id/qucosa%3A35393.
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This paper presents a brief study of the two most commonly used topologies - segmented and traveling-wave - for realizing monolithically integrated electro-optical transmitters consisting of Si-photonics Mach-Zehnder modulators and their electrical drivers. To this end, two new transmitters employing high swing breakdown voltage doubler drivers were designed in the aforementioned topologies and compared with regard to their extinction ratio and DC power consumption at the data rate of 30 Gb/s. It is shown that for the targeted data rate and extinction ratio, a considerably lower power consumption can be achieved with the traveling-wave topology than with its segmented counterpart. The transmitters were realized in a 250 nm SiGe BiCMOS electronic-photonic integrated technology.
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Aimone, Alessandro [Verfasser], Martin [Akademischer Betreuer] Schell, Martin [Gutachter] Schell, and Antonella [Gutachter] Bogoni. "InP segmented Mach-Zehnder modulators with advanced EO functionalities / Alessandro Aimone ; Gutachter: Martin Schell, Antonella Bogoni ; Betreuer: Martin Schell." Berlin : Technische Universität Berlin, 2016. http://d-nb.info/1156016681/34.
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Ferrotti, Thomas. "Design, fabrication and characterization of a hybrid III-V on silicon transmitter for high-speed communications." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEC054/document.
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Depuis plusieurs années, le volume de données échangé à travers le monde augmente sans cesse. Pour gérer cette large quantité d’information, des débits élevés de transmission de données sur de longues distances sont essentiels. Puisque les interconnections à base de cuivre ne peuvent pas suivre cette tendance, des systèmes de transmission optique rapides sont requis dans les centre de données. Dans ce contexte, la photonique sur silicium est considérée comme une solution pour obtenir des circuits photoniques intégrés à un coût réduit. Bien que cette technologie ait connu une croissance significative au cours de la dernière décennie, les transmetteurs actuels à haut débit de transmission sont principalement basés sur des sources laser externes. Par conséquent, l’objectif de ce travail de thèse était de concevoir et produire un transmetteur à haut débit de transmission de données pour la photonique sur silicium, doté d’une source laser intégrée.Ce transmetteur se compose d’un modulateur silicium de type Mach-Zehnder, co-intégré sur la même plaque avec un laser hybride III-V sur silicium à réseaux de Bragg distribués, dont la longueur d’onde d’émission peut être contrôlée électriquement autour de 1.3μm. La conception des différents éléments constituant à la fois le laser (coupleurs adiabatique entre le III-V et le silicium, miroirs de Bragg) et le modulateur (jonctions p-n, électrodes à ondes progressives) est détaillée, de même que leur fabrication. Pendant la caractérisation des transmetteurs, des taux de transmission de données jusqu’à 25Gb/s, pour des distances allant jusqu’à 10km ont été démontrés avec succès, avec la possibilité de contrôler la longueur d’onde jusqu’à 8.5nm. Par ailleurs, afin d’améliorer l’intégration de la source laser avec le circuit photonique sur silicium, une solution basée sur le dépôt à basse température (en-dessous de 400°C) d’une couche de silicium amorphe pendant la fabrication est aussi évaluée. Des tests sur une cavité laser à contre-réaction distribuée ont montré des performances au niveau de l’état de l’art (avec des puissances de sortie supérieures à 30mW), prouvant ainsi la viabilité de cette approcheFor several years, the volume of digital data exchanged across the world has increased relentlessly. To manage this large amount of information, high data transmission rates over long distances are essential. Since copper-based interconnections cannot follow this tendency, high-speed optical transmission systems are required in the data centers. In this context, silicon photonics is seen as a way to obtain fully integrated photonic circuits at an expected low cost. While this technology has experienced significant growth in the last decade, the high-speed transmitters demonstrated up to now are mostly based on external laser sources. Thus, the aim of this PhD thesis was to design and produce a high-speed silicon photonic transmitter with an integrated laser source.This transmitter is composed of a high-speed silicon Mach-Zehnder, co-integrated on the same wafer with a hybrid III-V on silicon distributed Bragg reflector laser, which emission wavelength can be electrically tuned in the 1.3μm wavelength region. The design of the various elements constituting both the laser (III-V to silicon adiabatic couplers, Bragg reflectors) and the modulator (p-n junctions, travelling-wave electrodes) is thoroughly detailed, as well as their fabrication. During the characterization of the transmitters, high-speed data transmission rates up to 25Gb/s, for distances up to 10km are successfully demonstrated, with the possibility to tune the operating wavelength up to 8.5nm. Additionally, in order to further improve the integration of the laser source with the silicon photonic circuit, a solution based on the low-temperature (below 400°C) deposition of an amorphous silicon layer during the fabrication process is also evaluated. Tests on a distributed feed-back laser structure have shown performances at the state-of-the-art level (with output powers above 30mW), thus establishing the viability of this approach
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Bhatambrekar, Nishant. "Realizing a fractional volt half-wave voltage in Mach-Zehnder modulators using a DC biased push-pull method and synthesis and characterization of indole based NLO chromophores for improving electro-optic activity /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/11606.
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Lange, Sophie Gloria [Verfasser], Klaus [Akademischer Betreuer] Petermann, Klaus [Gutachter] Petermann, Martin [Gutachter] Schell, and Markus-Christian [Gutachter] Amann. "Optical feedback effects within 1.55 μm InP-based DFB laser integrated Mach-Zehnder modulators for up to 100 GBd data transmission / Sophie Gloria Lange ; Gutachter: Klaus Petermann, Martin Schell, Markus-Christian Amann ; Betreuer: Klaus Petermann." Berlin : Technische Universität Berlin, 2019. http://d-nb.info/1185571809/34.
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Dye, S. P. "Compensation techniques for Mach Zehnder intensity modulator nonlinearities." Thesis, University of Kent, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308829.
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Prades, Jérémie. "Conception d’un modulateur électro-optique Mach Zehnder 100 Gbits/s NRZ sur silicium." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0205/document.
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Le développement permanent des applications informatiques telles que le stockage de masse, le calcul intensif et les communications large bande, encourage l’émergence de nouvelles technologies de communication. D’une part, les communications à travers des interconnexions métalliques approchent de leurs limites intrinsèques en termes d’énergie, surface et coût par bit. D’autre part, la photonique hybride conventionnelle, basée sur des assemblages 2D/3D de composants photoniques en technologies III-V, ne peut pas être complètement intégrée. Le développement de nouvelle architecture photonique sur silicium est une bonne alternative afin de proposer des systèmes intégrés de communication haut débit. La conception d’un modulateur électro-optique à très haut débit sur silicium fait l’objet de cette thèse. Dans un premier temps, un état de l’art des différents systèmes optiques est dressé, afin d’identifier les principaux verrous technologiques limitant leurs performances. Suite à l’analyse des différents types de modulateur optique implémentés sur silicium, une proposition d’architecture a été faite pour un modulateur Mach Zehnder 100 Gbits/s. Ce premier circuit a été développé avec la technologie PIC25G du fondeur STMicroelectronics. Le driver de ce modulateur a, quant à lui, été conçu avec la technologie 55 nm SiGe BiCMOS de ce même fondeur. Le démonstrateur proposé dans ces travaux offre un débit de 100 Gbits/s avec une modulation NRZ sur une unique voie optique. Pour cette configuration, ce prototype offre un débit binaire au-delà de l’état de l’art (pour une unique voie de transmission optique) avec une énergie par bit de 80 pJ/bitThe sustained development of software applications including mass storage, intensive computing and broadband communication, motivates the emergence of novel communication technologies. On one hand, communications through metallic interconnections approach their inherent limitations in term of energy, area and cost per bit. On the other hand, conventional hybrid photonics, based on discrete 2D/3D photonic assemblies of III-V photonic devices, cannot be integrated. The rising silicon photonic technology, thanks to its high level of integration, overcomes the shortcomings of the two previous approaches and promises a low cost solution allowing close proximity integration of photonics with electronics.The design of a very high data rate electro-optic modulator on silicon is reported in this thesis manuscript. In a first section, the state of the art of optic systems is presented with a focus on the main technological challenges limiting performances. Then, a silicon based topology is introduced to achieve a 100 Gbs Mach Zehnder modulator. It was implemented with the STMicroelectronics PIC25G technology. The driver of this modulator was designed with the 55 nm SiGe BiCMOS technology of the same founder. The demonstrator introduced in this work offer a 100 Gbs data rate with an NRZ modulation on a single optical channel. For this configuration, this prototype provides a data rate beyond the state of the art (for a single optical transmission path) with an energy per bit of 80 pJ/bit
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Radouani, Rachid Fontana Marc Abdi Farid. "Dérive dans les modulateurs électro-optiques Mach-Zehnder analyse physique et résolution /." [S.l.] : [s.n.], 2006. ftp://ftp.scd.univ-metz.fr/pub/Theses/2006/Radouani.Rachid.SMZ0622.pdf.
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Radouani, Rachid. "Dérive dans les modulateurs électro-optiques Mach-Zehnder : analyse physique et résolution." Metz, 2006. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2006/Radouani.Rachid.SMZ0622.pdf.
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Les modulateurs développés actuellement pour les télécommunications optiques à haut débit souffrent généralement, dans leur partie DC, d’un phénomène de dérive, dont les causes ne sont pas totalement élucidées. Afin de trouver des origines de cette dérive nous avons commencé par caractériser un modulateur Mach-Zehnder commercial. Ceci nous a permis d’identifier l’existence de trois phénomènes : un premier phénomène à temps de réponse rapide lié à la couche de silice, un deuxième lié à l’anisotropie du substrat et un troisième phénomène corrélé aux hétérogénéités de surface induites lors de la fabrication du composant. Cette analyse nous a conduit à envisager une solution aux problèmes des dérives liées à la relaxation des charges dans la structure du composant. Cette solution consiste à compenser les dérives liées à l’anisotropie du substrat de LiNbO3 par celles dues aux hétérogénéités électriques de surface. Afin de mettre en oeuvre cette solution nous avons développé un modèle physique basé sur les équations de Maxwell qui permet de calculer la carte de conductivité idéale permettant de supprimer la dérive à long terme. Ce calcul nécessite la connaissance des temps de réponse caractéristiques du substrat de LiNbO3. C’est pourquoi nous avons mis en place deux bancs de mesures, un montage de Sénarmont et un interféromètre de Mach-Zehnder. Ces montages nous ont permis de mesurer l’évolution temporelle du champ électrique induit dans le substrat lors de l’application d’un échelon de tension et d’en déduire ces temps de réponsesThe modulators currently developed for high speed optical telecommunications generally suffer, in their DC part, from a drift phenomenon, whose causes are not completely understood. In order to find the origins of this drift we started by characterizing a commercial Mach-Zehnder modulator. This enabled us to identify the existence of three phenomena : a first phenomenon with a fast response time related to the silica layer, a second one related to the anisotropy of the substrate and a third phenomenon linked to the heterogeneities of surface induced during the fabrication of the device. This analysis led us to consider a solution to the problems of the drifts related to charges relaxation in the structure of the device. This solution consists in the compensation of the drifts related to the anisotropy of the substrate of LiNbO3 by those due to the electric heterogeneities of the surface. In order to implement this solution we have developed a physical model based on the Maxwell’s equations which allows to calculate the map of the ideal electrical conductivity allowing to remove the long-term drift. This calculation requires the knowledge of the response times of the LiNbO3 substrate. This is why we have developed two experimental setups, one based on the Senarmont’s method and the other on a Mach-Zehnder interferometer. These setups enabled us to measure the temporal evolution of the electric field induced in the substrate during the application of a voltage step and to deduce these response times from them
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KHALFALLAH, Sabry. "Modulateurs de cohérence en optique intégrée sur semiconducteurs III.V : guide biréfringent et interféromètre de Mach-Zehnder." Phd thesis, Université Paul Sabatier - Toulouse III, 1997. http://tel.archives-ouvertes.fr/tel-00010242.
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Cette étude porte sur la conception, la réalisation et la caractérisation de modulateurs de cohérence intégrés sur substrats semiconducteurs III-V. Nous expliquons tout d'abord le principe de la modulation de cohérence, technique particulière de codage optique appliquée à la transmission et au multiplexage de signaux, qui repose sur l'introduction dans un interféromètre à deux ondes d'un retard optique supérieur à la longueur de cohérence de la source optique. Nous avons réalisé un premier modulateur de cohérence, interféromètre à polarisation à base de guide d'onde optique ruban fortement biréfrigent. Les semiconducteurs III-V n'étant pas biréfringents nous avons développé une structure originale permettant le guidage des seuls modes fondamentaux TE0 et TM0 avec une forte biréfringence de forme résultant de l'empilement de nombreuses couches de GaAlAs de faible épaisseur. Les deux modes présentent en sortie du guide une différence de chemin optique de 230 mm, modulable par effet électro-optique et supérieure à la longueur de cohérence d'une diode superluminescente à 1.3 mm. Nous avons ensuite réalisé un second modulateur sous la forme d'un interféromètre de Mach-Zehnder fortement déséquilibré. Cet interféromètre à deux ondes entièrement intégré en GaAlAs/GaAs introduit un retard optique de 100 mm, par différence de longueur de ses bras. Afin de minimiser les pertes dans cette structure de géométrie complexe nous avons gravé des tranchées situées à l'extérieur des zones courbées. Cette solution a été choisie aprés simulation du dispositif par la méthode des faisceaux propagés (BPM). Les performances du composant sont comparables à celles du précédent. Nous avons donc réalisé les premiers modulateurs de cohérence intégrés en semiconducteurs III-V qui ouvrent la voie à de nouvelles applications en filtrage, contrôle de polarisation... dans les réseaux de télécommunications optiques.
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KHALFALLAH, SABRY. "Modulateurs de coherence en optique integree sur semiconducteurs iii-v : guide birefringent et interferometre de mach-zehnder." Toulouse 3, 1997. http://www.theses.fr/1997TOU30235.
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Cette etude porte sur la conception, la realisation et la caracterisation de modulateurs de coherence integres sur substrats semiconducteurs iii-v. Nous expliquons tout d'abord le principe de la modulation de coherence, technique particuliere de codage optique appliquee a la transmission et au multiplexage de signaux, qui repose sur l'introduction dans un interferometre a deux ondes d'un retard optique superieur a la longueur de coherence de la source optique. Nous avons realise un premier modulateur de coherence, interferometre a polarisation a base de guide d'onde optique ruban fortement birefrigent. Les semiconducteurs iii-v n'etant pas birefringents nous avons developpe une structure originale permettant le guidage des seuls modes fondamentaux te#0 et tm#0 avec une forte birefringence de forme resultant de l'empilement de nombreuses couches de gaalas de faible epaisseur. Les deux modes presentent en sortie du guide une difference de chemin optique de 230 m, modulable par effet electro-optique et superieure a la longueur de coherence d'une diode superluminescente a 1. 3 m. Nous avons ensuite realise un second modulateur sous la forme d'un interferometre de mach-zehnder fortement desequilibre. Cet interferometre a deux ondes entierement integre en gaalas/gaas introduit un retard optique de 100 m, par difference de longueur de ses bras. Afin de minimiser les pertes dans cette structure de geometrie complexe nous avons grave des tranchees situees a l'exterieur des zones courbees. Cette solution a ete choisie apres simulation du dispositif par la methode des faisceaux propages (bpm). Les performances du composant sont comparables a celles du precedent. Nous avons donc realise les premiers modulateurs de coherence integres en semiconducteurs iii-v qui ouvrent la voie a de nouvelles applications en filtrage, controle de polarisation. . . Dans les reseaux de telecommunications optiques.
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Pawela, Yvan. "Etude de la correction du point de fonctionnement de modulateurs éléctro-optiques intégrés sur niobate de lithium par laser femtoseconde." Besançon, 2012. http://www.theses.fr/2012BESA2037.
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Ces recherches visent a développer une technique d'usinage du niobate de lithium par laser femtoseconde pour des applications en optique intégrés. Cette approche originale permet de corriger, post fabrication et en direct, le point de fonctionnement statistique des modulateurs d'intensité basés sur une architecture d'interféromètre de Mach-Zehnder. En théorie, les modulateurs d'intensité sont dans l'état passant quand ils sont au repos. C'est à dire que la point de fonctionnement se trouve au maximum de la fonction de transfert modulateur. En réalité, les techniques de fabrication par photolithographie de permettent pas d'obtenir ce résultat. Par ailleurs, suivant les applications, le point de fonctionnement des modulateurs est souvent réglé dans la zone linéaire, au maximum ou encore au minimum de la fonction de transfert. Actuellement le moyen utilisé pour régler ce point de fonctionnement est l'application d'un champ électrique statique, qui modifie la réponse du modulateur par effet électro-optique linéaire. Cependant l'application de cette tension peut créer un transfert de charges dans le niobate qui induit une dérive de la fonction de transfert du modulateur au cours du temps. Cela nécessite l'ajout d'une solution d'asservissement de cette tension en fonction de la dérive de la fonction de transfert du modulateur. Le micro usinage par laser femtoseconde de la surface du guide optique composant le modulateur, permet d'introduire un déphasage permanent. Ce déphasage est dû à la variation locale de l'indice de réfraction du guide introduite par l'impact laser. En contrôlant parfaitement le déphasage introduit, nous pouvons régler le point de fonctionnent statique des modulateurs d'intensité. Il est donc possible de s'affranchir de la tension continue initialement utilisée pour régler le point de fonctionnement. Des simulations numériques ont permis de démontrer la faisabilité du procédé. La démonstration expérimentale a été réalisée mais des limitations liées à la technologie utilisée ont été mises en évidence dans le cadre d'une utilisation industrielleThe goal of this work is t he development of femtosecond laser micromachining for integrated optics applications. This original method allows us to adjust, in real time and post fabrication, the bias point or intensity modulators baser on the Mach-Zehner interferometer. In theory , intensity modulators are in the 'on ' state when no external voltage is applied. That is to say, the bias point is in the maximum of the modulator transfer function. Actually, we can't obtain this state due to the subtleties if the photo lithography process used in fabrication. Besides, depending on each application, the bias point is often required to be set on the linear region of the modulator transfer function. Currently, DC electric fields are used to adjust the bias point via linear electro-optic effect. However, this DC field can introduce a drift in the modulator function transfer over time. This method thus requires a modulator bias controller to adjust automatically the bias point. Femtosecond micromachining of the optical wave guide surface of intensity modulator introduce a permanent phase difference between the two arms of the two arms of the Mach-Zehner interferometer. This phase offset is due to local variations of the refractive index introduced by the femtosecond laser micromachining. The static bias point can then be adjusted bu controlling the phase difference between both arms of the interferometer. Experimental proof-of-principle demonstrations have been performed but technological limitations appear in an industrial context
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Fehrman, Cory Emily Marie. "Fabrication of a Deoxyribonucleic Acid Polymer Ridge Waveguide Electro-Optic Modulator by Nanoimprint Lithography." University of Dayton / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1398419640.
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Cavaco, Telmo Filipe Pedrosa. "Compensation of MZ-IQ-modulator nonlinearity based on FPGA algorithms." Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/12677.
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Mestrado em Engenharia Electrónica e TelecomunicaçõesNos últimos anos, a crescente necessidade de largura de banda e a evolução das técnicas de processamento digital de sinal renovaram o interesse pelos sistemas de comunicação ópticos coerentes. O modulador IQ assume-se como um componente chave nestes transmissores, sendo responsável pela conversão de informação do domínio eléctrico para o domínio óptico. Os moduladores Mach-Zehnder que constituem este dispositivo recebem sinais de drive com uma excursão controlada, garantindo a utilização de uma região aproximadamente linear das suas funções transferência e a geração de constelações sem distorções de fase. No entanto, existem vantagens em explorar a extensão completa da característica dos moduladores. Neste contexto, torna-se relevante efectuar um estudo acerca das técnicas de pré-distorção electrónica que permitem corrigir os efeitos das não-linearidades associadas a este método de transmissão. Esta dissertação foca-se no estudo da compensação dos impactos que a característica não-linear do modulador Mach-Zehnder tem nos sistemas de transmissão ópticos coerentes. Após a identificação e desenvolvimento de soluções matemáticas para o problema, realizaram-se vários testes utilizando um simulador integrado em ambiente MATLAB. Um sistema de transmissão coerente utilizando formatos de modulação QAM e os respectivos algoritmos de compensação foram posteriormente implementados em FPGA. Desenvolveram-se também co-simulações que permitiram garantir que o hardware concebido produzia os resultados desejados. Para além disso, realizaram-se vários testes utilizando um modulador IQ disponível no “Laboratório de Óptica” do Instituto de Telecomunicações de Aveiro. O objectivo consistiu em operar o sistema em condições laboratoriais e analisar o desempenho dos algoritmos de compensação em ambiente real.
In recent years, the ever-increasing bandwidth demand and the evolution of digital signal processing techniques renewed the interest for the optical coherent systems. The IQ-Modulator is a key component in optical coherent transmitters, being responsible for the conversion of information from electrical to optical domain. The Mach-Zehnder modulators that compose this device receive driving signals with a controlled excursion, in order to use an approximately linear region of their transfer function and produce constellations without phase distortions. However, there are advantages in exploit the full range of the modulators’ characteristic. In this context, a study about the electronic predistortion techniques required to overcome the nonlinear effects associated to this transmission method becomes relevant. The subject of this dissertation is the compensation of impairments related to the nonlinear characteristic of the Mach-Zehnder Modulator in coherent optical transmission systems. After the identification and development of mathematical solutions for the problem, several tests were made using a simulator that runs in a MATLAB environment. A QAM coherent transmitter system and the compensation algorithm were then implemented in a FPGA platform. Co-simulations were performed in order to prove that the designed hardware was generating correct results. Furthermore, some tests were conducted using an IQ-Modulator available in the “Optics Laboratory” at Telecommunications Institute of Aveiro. The goal was to operate the system under laboratorial conditions and analyze the performance of the compensation algorithm in a real case scenario.
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Barč, Andrej. "Přenos radiofrekvenčního signálu optickým vláknem." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442409.
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This work deals with the transmission of optical radiation modulated by a radio frequency signal through an optical fiber. Furthermore, it describes the principles of communication and area coverage. It points out the practical use of components located in the communication chain of this system. Explains the functionality of the properties and the division of individual components. It introduces the benefits and limitations of this system. It further describes the creation of a topology suitable for laboratory measurement of RoF technology. Provides experimental measurement of C-band parameters. Indicates the possible use of RoF technology using a wireless optical link. A part of the work is also a sample laboratory protocol.
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Chen, Chii-Chang. "Etude des variations de phase de modulateurs optiques intégrés à base de LiNbO3 induites par ablation laser." Besançon, 1998. http://www.theses.fr/1998BESA2034.
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Cette thèse se situe dans le cadre des télécommunications optiques appliquées aux réseaux locaux. Elle s'applique plus particulièrement aux transmissions bidirectionnelles impliquant une source lumineuse installée au niveau du central. Le but de cette étude est de réaliser le miroir électro-optique de type Mach-Zehnder replié installé chez abonné caractérisé par son indépendance à l'état de polarisation de la lumière incidente lors de la propagation dans la fibre optique monomode de transmission. Les dispositifs sont réalisés à partir de cristaux de niobate de lithium dont l axe de propagation est orienté selon l'axe optique Z. L'indépendance par rapport à l'état de polarisation est possible si les longueurs des bras du modulateur sont strictement identiques. Cependant la fabrication des deux bras de longueur identiqùe est très difficile à contrôler expérimentalement, générant ainsi une différence de phase entre les modes TE ef TM. Cette thèse propose l'étude des variations de phase induite par ablation Laser excimère de la surface du guide d'onde optique. Il s'agit de modifier l'indice effectif du mode se propageant dans un des bras sur une longueur suffisante pour compenser l'écart de phase produit par la différence de longueur statique entre les bras. On applique ensuite les résultats issus de cette méthode sur un coupleur directionnel pour modifier ou corriger le taux de couplage d'un tel dispositifThis thesis deals with optical fiber telecommunication systems applied to local area networks. The system allows a bidirectional transmission using only one optical source installed in the distribution canter. The aim of this thesis is to realize a polarization-independent Mach-Zehnder interferometer working as a reflecting modulator at the subscriber and receiver-emitter. The modulators are integrated in a Z-propagation LiNbO3 crystal. The polarization-independent behavior can be obtained if the lengths of the bath arms of the modulator are strictly equal. However, identical lengths of the arms are difficult to obtain with the fabrication process, and small errors can induce an additional phase term in the electro-optic responses of the TE- and TM-modes. The solution proposed in this thesis uses excimer laser ablation applied on the surface of one waveguide arm of the modulator in order to achieve an accurate phase bias trimming. This method modifies the effective index on a section of waveguide resulting in the matching of the phase difference between the TE- and TM-modes produced by the fabrication process. We have also applied the results obtained by the laser ablation method to a directional coupler in order to modify or correct the mode coupling length of the coupler
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El, Mansouri Ibrahim. "Sources impulsionnelles picosecondes tout optique à très haut débit : applications aux télécommunications optiques." Thesis, Dijon, 2013. http://www.theses.fr/2013DIJOS064/document.
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Ce mémoire de thèse présente les travaux effectués pour la réalisation de sources optiques fibrées d’impulsions picosecondes cadencées à 40 GHz dans la bande C des télécommunications. Dans une première partie, nous présentons des études numériques et expérimentales mises en place pour la génération d’un train d’impulsions cadencé à 40 GHz par la compression non-linéaire d’un battement sinusoïdal via un processus de mélanges à quatre ondes multiples. Afin d’obtenir des impulsions stables, le battement sinusoïdal initial est obtenu par la modulation en intensité d’un signal continu grâce à un modulateur Mach-Zehnder piloté au point nul de transmission. Nous démontrons également l’amélioration de la qualité des impulsions générées par la suppression de la diffusion Brillouin stimulée grâce à la mise en place d’isolateurs optiques dans la ligne fibrée de la source. Nous présentons ensuite la génération d’impulsions ultra-courtes grâce à un compresseur non-linéaire composé de quatre étages fibrés. Le train d’impulsions obtenu est alors codé puis multiplexé jusqu’à un débit optique de 160 Gbit/s. Dans la dernière partie, nous présentons les démarches mises en place en vue d’un transfert technologique, telles que la réalisation d’un prototype de la source, la recherche d’antériorité et l’étude de marchéThis thesis presents the work carried out on the realization of fibered 40-GHz picosecond optical pulse sources in the telecommunications C-band. In the first part, we present a numerical and experimental study of the generation of 40-GHz pulse trains thanks to the nonlinear compression of an initial beat-signal by multiple Four-Wave Mixing process. Enhanced temporal stability is achieved by generating the sinusoidal beating thanks to a Mach-Zehnder modulator driven at its zero-transmission working point. In order to improve the quality of the generated pulses, we also demonstrate the suppression of stimulated Brillouin back-scattering by inserting several optical isolators into the compression line. In the next part, we present the generation of low duty-cycle pulse trains by using a nonlinear compressor line based on 4 segments of fiber. The generated pulse trains have been encoded and then multiplexed to achieve a high bit rate signal (160 Gb/s). In the last part, we present the technology transfer steps of this optical source, such as creating a prototype of the source, prior art search and market research
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Tsou, Benny Pen-Cheng. "Electrooptic mach-zehnder modulators in gallium arsenide." Thesis, 1993. http://hdl.handle.net/2429/1511.
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External travelling-wave modulators, utilizing the electrooptic effect, are one class of devices currently being investigated for converting electrical signals to optical signals in applications involving high-speed data transmission. Modulators fabricated on semiconductor substrates, such as GaAs and InP, are particularly attractive in that there exists the possibility of monolithic integration of these devices with other optoelectronic components. The bandwidths of this type of modulator are limited by the velocity mismatch between the microwave and the optical wave, where, in these compound semiconductors, the microwave has the greater phase velocity. To eliminate this problem, a slow-wave electrode structure has been developed in our laboratory in which the phase velocity of the microwave is reduced to match the phase velocity of the optical wave. In this thesis, modulators, based on the integrated optics version of the Mach-Zehnder interferometer, using GaAs substrates, were modelled and fabricated for use with these slow-wave electrodes. The variational method, effective-index method, and beam propagation method were used to model the propagation of light in these devices, and, hence, obtaining the necessary design parameters for these devices. Based on these numerical simulations, modulators were designed and fabricated in AlGaAs epitaxial layers, grown on GaAs substrates by the metal organic chemical vapour deposition technique. Optical attenuation in the waveguides was measured. Parameters such as the half-wave voltage, intrinsic bias, extinction ratio, and microwave indices of the electrodes were measured. The extinction ratio, for most devices, was greater than 99%. The half-wave voltage and the microwave indices, which could be calculated theoretically, were found to be in good agreement with the measured values.
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MacKay, Alex William. "Complex Phase Biasing of Silicon Mach-Zehnder Interferometer Modulators." Thesis, 2014. http://hdl.handle.net/1807/44043.
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A new any-point biasing scheme for Mach-Zehnder interferometer modulators which considers the complex phase is proposed. The Mach-Zehnder arm loss imbalance (imaginary part of the phase bias) is found by slightly perturbing the real and imaginary parts of the phase in each arm with low frequency pilot tones and monitoring and manipulating the spectral content at the output. This technique can be used to extend the possible extinction ratio, reduce the phase error, and better quantify the system chirp but also has some performance degradations which are also quantified and discussed. Simulation results indicate that the maximum extinction ratio of a typical modulator can be extended to ≳ 40 dB and maintained in the presence of ambient complex phase drift in the arms. Practical challenges for implementing this method with a silicon Mach-Zehnder modulator are discussed, but the analysis is general to other material platforms.
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Lee, Bo-Yuan, and 李博淵. "Si and C-rich SiC Based Mach-Zehnder Modulators." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/kj277c.
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碩士國立臺灣大學
光電工程學研究所
107
In this thesis, the silicon-based Mach-Zehnder modulator and the C-rich SiCx based micro-ring assisted Mach-Zehnder modulator were analyzed to achieve high-speed data transmission whatever utilizing the electro-optic effect or all-optical nonlinear Kerr effect. The single-arm driven asymmetric Si MZM demonstrates the high-speed data transmission for short- and long-reach data center applications with the non-return-to-zero on-off keying (NRZ-OOK) and 4-level pulse amplitude modulation (PAM-4). The C-rich SiCx micro-ring assisted MZM waveguide was simulated, fabricated and analyzed for achieving all-optical wavelength conversion and chirp-dispersion compensation based on Fano resonance-enhanced nonlinear Kerr switching. In chapter 2, a 1550-nm single-arm driven asymmetric silicon Mach-Zehnder modulator (MZM) based on electro-optic effect for single-channel 100-Gbit/s 4-level pulse amplitude modulation (PAM-4) data with waveform pre-emphasis is demonstrated. The 2-mm phase shifter under carrier depletion of pn junction structure exhibits low VπL product and high extinction ratio of 0.909 V·cm and 12.7 dB, respectively. Such a low VπL product satisfying the criterion of data center standard of 1.7 V·cm leads the device to perform high-speed data transmission. In addition, the optical light through single-arm driven asymmetric Si MZM offers an average power of 0 dBm and an excellent side mode suppression ratio of 58.28 dB. With impedance matching of 50-GHz 50-Ω terminator at the end port, the modulation bandwidth of single-arm driven asymmetric Si MZM can reach as high as 33 GHz. To minimize the chromatic dispersion induce RF fading, the dispersion-shift fiber (DSF) is utilized to replace the single-mode fiber (SMF). For non-return-to-zero on-off keying (NRZ-OOK) data to meet the error-free criterion, the single-arm driven asymmetric Si MZM supports the highest modulation capacities of 53/53/50 Gbit/s over BtB, 2-km SMF and 10-km DSF transmission, respectively, and the receiving power penalties at 50 Gbit/s can achieve 0.2 and 0.25 dB after 2-km SMF and 10-km DSF propagation, respectively. To further improve the transmission performance, the PAM-4 data is employed to effectively utilize the limited modulation bandwidth. The maximal transmission capacities of BtB, 2-km SMF and 10-km DSF to meet KP4-FEC criterion are improved to 50/50/26 Gbaud (100/100/52 Gbit/s) with qualified BER of 1.52×10^-4/1.96×10^-4/1.36×10^-4, and the received 50-Gbaud PAM-4 data link provides a power penalty of 0.32 dB over 2-km SMF transmission. For a fair comparison at 26 Gbaud, the received PAM-4 data reveals power penalties of 0.26 dB and 0.64 dB after 2-km SMF and 10-km DSF transmission, which suffers from the propagation loss and core mismatch induced coupling loss. In chapter 3, the C-rich SiCx micro-ring assisted Mach-Zehnder modulator (MZM) waveguide is demonstrated for all-optical cross-wavelength 25-Gbit/s pulsed return-to-zero on-off keying (PRZ-OOK) data conversion based on enhanced nonlinear Kerr switching. By adjusting the [CH4]/([CH4]+[SiH4]) fluence ratio to 0.94, the C-rich SiCx micro-ring assisted MZM waveguide enlarges its nonlinear refractive index up to 2.5×10-12 cm2/W at 1550 nm, which can induce a red shift of 0.12 nm on the transmittance notch under the intensive pump. To improve the conversion efficiency of all-optical pump-to-probe wavelength conversion, the micro-ring assisted MZM is employed for interfering the sharp lineshapes of Fano resonance. In addition, the designed C-rich SiCx micro-ring assisted MZM waveguide exhibits flat chromatic dispersion at C- and L-band wavelengths with a positive group velocity dispersion (β2) of 2973 ps2/km at 1550 nm, which is potential for applying on wavelength division multiplexer (WDM) and compensating the signal distortion induced by negative β2 or negative chirp components. By analyzing the frequency chirp of three optical pulses with pulsewidths of 100/40/20 ps before and after passing through the C-rich SiCx micro-ring assisted MZM waveguide, the suppression of frequency chirp from -5.6/-8/-10.4 GHz to -1.7/-2.2/-2.5 GHz is observed with its corresponding pulsewidth broadening factors (To/Ti) of 0.96/0.97/0.976. Under pump-to-probe wavelength conversion, the full width at half maximum of the modulated probe is suppressed from 47.3 ps to 42.08 ps and 41.55 ps at a wavelength around 1547.98 nm and 1558.28 nm due to the chirp-dispersion compensation of the C-rich SiCx micro-ring assisted MZM waveguide. In application, the dense C-C bonds content formed by high C/Si composition ratio contribute to an enhanced nonlinear Kerr switching, which enables the all-optical PRZ-OOK data format conversion and inversion at 25 Gbit/s and qualifies the criterion of the complementary metal-oxide-semiconductor logics. These results reveal that the C-rich SiCx assisted MZM waveguide can be versatile functionalities including the chirp-dispersion compensation, wavelength conversion, and data-format conversion/inversion.
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Chen, Yin-Jui, and 陳盈瑞. "Design and Analysis of High Speed Silicon Mach-Zehnder Optical Modulators and Germanium Photodetectors." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/eg87t2.
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碩士國立清華大學
光電工程研究所
107
With continuous demand for data transmission during the past few years. This has resulted in an unprecedented demand in the speed and volume of data transmission. Compared with the electric transmission system, the optical transmission system has lower energy loss and has higher transmission speed. The main devices of this thesis are high-speed silicon electro-optical modulators and high-speed germanium photodetectors. We design and integrate the above two devices to construct silicon photonic integrated circuits for radio-over-fiber system with upload and download functions. In this thesis, we design the silicon optical modulators and germanium photodetectors based on their equivalent circuit model. At first, we design the passive devices (optical waveguide, grating coupler, multimode interference coupler and wavelength demultiplexer) in silicon photonic integrated circuits for radio-over-fiber system. Then, we establish the design flow according to the relationship between the characteristics and parameters of the devices. Next, we optimize the dimension of silicon(germanium) waveguide, modulation (photodetection) region, size and length of traveling-wave electrode based on the design flow. According to the simulation(measurement) results of optical modulators, the operation bandwidth is about 37(21)GHz / 23(10)GHz when the length of the electrode is 1mm / 2mm. According to the simulation result of germanium photodetectors, the operation bandwidth is about 20GHz(25GHz) when the width of the germanium waveguide is 0.5μm(0.4μm). In the measurement of silicon optical modulators, we successfully observe the eye diagram under 32Gb/s(28Gb/s) modulation when the length of the electrode is 1mm(2mm).
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Chung, Wei-Lun, and 鐘偉綸. "Design and Analysis of the Travelling Wave Electrode for High Speed Silicon Mach-Zehnder Optical Modulators." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/7syq88.
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碩士國立清華大學
光電工程研究所
106
In the past decade, a significant increase in Internet access is driven by an abundance of cloud-based storage and computing, high-definition multimedia streaming, and a lot of Internet services. This has resulted in an unprecedented demand in the speed and volume of data transmission. Compared with the electric transmission system, the optical transmission system has lower power consumption and has higher transmission speed. In order to implement a high-speed optical transmission system, designing a high-speed electro-optical modulator that is able to convert electrical signal into optical signal efficiently is an important target. In this thesis, we focus on the design and analysis of a travelling wave Si Mach-Zender modulator, where the active region is made of a L-shaped PN junction inside a waveguide for the operating wavelength near 1550 nm. Compared with different element length, different implant concentration, different MMI and the symmetric and asymmetric modulator to optimize the parameters of the MZI optical modulator. The S parameters show that the modulation bandwidths of a 1mm and a 2 mm MZI modulator are 71Gb/s and 47Gb/s respectively, with an employment of a TWE design. The 2 mm asymmetric MZI optical modulator successfully modulates the 25Gboud (50Gb/s) PAM4 signal driven by electrical PAM4. Finally, the MZI optical modulator packaged with a CMOS driver was successfully demonstrated with a modulation speed of 25Gb/s OOK optical signal.
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Klein, Holger [Verfasser]. "Integrated InP Mach-Zehnder modulators for 100 Gbit/s Ethernet applications using QPSK modulation / vorgelegt von Holger Klein." 2010. http://d-nb.info/1010051199/34.
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Palaniappan, Arun. "Modeling, Optimization and Power Efficiency Comparison of High-speed Inter-chip Electrical and Optical Interconnect Architectures in Nanometer CMOS Technologies." Thesis, 2010. http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8618.
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Inter-chip input-output (I/O) communication bandwidth demand, which rapidly scaled with integrated circuit scaling, has leveraged equalization techniques to operate reliably on band-limited channels at additional power and area complexity. High-bandwidth inter-chip optical interconnect architectures have the potential to address this increasing I/O bandwidth. Considering future tera-scale systems, power dissipation of the high-speed I/O link becomes a significant concern. This work presents a design flow for the power optimization and comparison of high-speed electrical and optical links at a given data rate and channel type in 90 nm and 45 nm CMOS technologies.
The electrical I/O design framework combines statistical link analysis techniques, which are used to determine the link margins at a given bit-error rate (BER), with circuit power estimates based on normalized transistor parameters extracted with a constant current density methodology to predict the power-optimum equalization architecture, circuit style, and transmit swing at a given data rate and process node for three different channels. The transmitter output swing is scaled to operate the link at optimal power efficiency. Under consideration for optical links are a near-term architecture consisting of discrete vertical-cavity surface-emitting lasers (VCSEL) with p-i-n photodetectors (PD) and three long-term integrated photonic architectures that use waveguide metal-semiconductor-metal (MSM) photodetectors and either electro-absorption modulator (EAM), ring resonator modulator (RRM), or Mach-Zehnder modulator (MZM) sources. The normalized transistor parameters are applied to jointly optimize the transmitter and receiver circuitry to minimize total optical link power dissipation for a specified data rate and process technology at a given BER.
Analysis results shows that low loss channel characteristics and minimal circuit complexity, together with scaling of transmitter output swing, allows electrical links to achieve excellent power efficiency at high data rates. While the high-loss channel is primarily limited by severe frequency dependent losses to 12 Gb/s, the critical timing path of the first tap of the decision feedback equalizer (DFE) limits the operation of low-loss channels above 20 Gb/s. Among the optical links, the VCSEL-based link is limited by its bandwidth and maximum power levels to a data rate of 24 Gb/s whereas EAM and RRM are both attractive integrated photonic technologies capable of scaling data rates past 30 Gb/s achieving excellent power efficiency in the 45 nm node and are primarily limited by coupling and device insertion losses. While MZM offers robust operation due to its wide optical bandwidth, significant improvements in power efficiency must be achieved to become applicable for high density applications.
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Hsiung, Yu Hsiu, and 余信雄. "A study of GaAs semiconductor Mach-Zehnder modulator." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/35646965501353345832.
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Ming, Hsu Jui, and 徐瑞明. "A study of integration of phase modulator and Mach-Zehnder modulator." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/17483214266779539989.
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王耀常. "Design and improvement of the broadband mach-zehnder optical modulator." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/34882806287298784976.
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Chen, Cho-Yan, and 陳卓彥. "Fabrication of Blue-Laser Zn-Ni Co-diffused Mach-Zehnder Modulator." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/63102397652415851181.
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碩士國立臺灣大學
光電工程學研究所
93
In this work, Zn-Ni:LiNbO3 single-mode waveguides and Mach-Zehnder modulators operated at blue-laser wavelength are demonstrated for the first time. To support the fundamental mode only, the largest linewidth of the Zn-Ni co-diffused waveguides should be about 1.5um, which is smaller than that of Ti-diffused waveguides, 2.5um. The optical confinement of the waveguides is optimized by diffusing at 830ºC for 60min when the thicknesses of nickel and zinc are 100Å and 500Å, respectively. Moreover, the Zn-Ni:LiNbO3 waveguides are free of lithium out-diffusion as that found in Ti:LiNbO3 waveguides. The Mach-Zehnder modulators operating at blue-laser wavelength are also demonstrated, the half voltage and the extinction ratio of the device are found to be 6.5V and 7dB, respectively.
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Hsien, Tsai Cheng, and 蔡政賢. "Monolithic Integration of a PIN Photodiode and Mach-Zehnder Electrooptical Modulator." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/90258875380599911966.
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Shu-YuChen and 陳淑瑀. "Spatial Light Modulator Coding effect on Measuring Image Objects over Mach-Zehnder Interferometry." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/40312419256286686236.
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碩士國立成功大學
光電科學與工程學系
102
Mach-Zehnder Interferometer (MZI) can be used to acquire the optical thickness of samples by utilizing the interference of two lights. Recently, some researchers mentioned that if a dispersion element is put in front of the interferometer, the coherence envelope of the signal will be broadened. The reason is that when the light passes the dispersion element, different refractive indices of different wavelengths in the dispersive medium. The intensity of the interference signal will oscillates, which leads to beat effect. As a result, multiple splitting of the partial-coherence interference (PCI) signal will be induced. Although the resolution of measurement decreases, the curve of the results will be smoother. Therefore, the precision of measuring multi-layer structures can be improved. We observe that the similar effect happens when encoding the signal. In this paper, we set up the spatial-light modulator (SLM) at the signal arm of the MZI to measure the optical thickness of the sample. Different coding patterns are used and discussed in this study. When proper encoding scheme is used in SLM, the signal peaks will be broadened. This effect can be utilized to measure multi-layer structures of object samples. When the incident light passes multi-layer structures, the signal is split into multiple peaks. Though the broadening of the signal decreases the resolution, we can acquire the desired peak and the curve becomes smoother. Therefore, the precision of the measurement can be improved. If this effect is combined with image processing, it can be used in medical fields. It can also be used in industry fields to measure the properties of samples.
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Tsai, Yan-Tso, and 蔡晏佐. "Design and Fabrication of Blue-Laser Mach-Zehnder Modulator with Multi-Mode Interference Structures." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/24302402497170439214.
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碩士國立臺灣大學
光電工程學研究所
96
In this work, Zn-Ni:LiNbO3 1×2 multimode interference power splitters and two kinds of Mach-Zehnder modulators operating at blue-laser wavelength are demonstrated for the first time. To support the fundamental mode only, the linewidth of the Zn-Ni co-diffused waveguides is found to be 1.6µm, and the optimal optical confinement of the waveguides is obtained by diffusing at 830ºC for 90 min when the thicknesses of nickel and zinc are 100 Å and 500 Å, respectively. The best 1×2 multimode interference power splitter exhibits a transmission of 75.12% as the width and the length of multimode interference region are 20μm and 600µm, respectively. The proposed Mach-Zehnder modulators with multimode interference structures operating at blue-laser wavelength are also demonstrated, and the halfwave voltage and the extinction ratio of the device are found to be 8.9V and 12.9dB, respectively. Moreover, the halfwave voltage and the extinction ratio of the Mach-Zehnder modulators with truncated branch structures are found to be 6.4V and 9.8dB, respectively.
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Chen, Shuo-Wei, and 陳碩偉. "Studies on Linearization of Mach-Zehnder Electrooptic Modulator Applied in Optical Fiber Analog Communications." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/19060866136198022543.
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Chen, Haitao [Verfasser]. "Development of an 80 Gbit/s InP-based Mach-Zehnder modulator / vorgelegt von Haitao Chen." 2007. http://d-nb.info/987073761/34.
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Tsai, Ying-Jhe, and 蔡英哲. "Design and Fabrication of Ridge Structure Mach-Zehnder Modulator with Gamma-Ray Irradiated Lithium Niobate." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/30386512507810604456.
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碩士國立臺灣大學
電子工程學研究所
98
In this thesis, ridge Mach-Zehnder modulator is successfully fabricated by using proton exchange wet etching in gamma ray irradiated z-cut lithium niobate. To characterize the effect of gamma ray irradiation, the depth and the aspect ratio of the ridge structure are measured by surface profiler and electron microscope. Experimental results show that the depth and the aspect ratio of the gamma ray irradiated ridge structure are increased by about 30% and 87%, respectively. Owing to deeper vertical side walls, the optical field confinement is enhanced and the drive voltage is decreased from 7.9V to 6V.
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Wu, Po-I., and 吳柏毅. "The Intergraded Electromagnetic Field Sensor Combining a Micro Antenna with a LiNbO3 Mach-Zehnder Waveguide Modulator." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/82836834360565881625.
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碩士國立成功大學
光電科學與工程研究所
94
The amplitude modulator of an electromagnetic field sensor using Ti diffusion process on Z-cut LiNbO3 and optical fiber link is improved by a Mach-Zehnder interferometer, whose Vπ is about 10V at 1550nm wavelength and the on-off extinction ratio is 23.8dB. In this thesis, the plane antenna was directly applied to suppress the volume and strengthen the connection between each part of the device for the purpose of optoelectronic intergraded circuit. After being ground and polished well, the device was coupled with fiber directly. Then the characteristic of the fabricated sensor were analyzed. It was found that the resulting frequency response is almost flat from 100MHz to 1.8GHz, and the resonant frequency is at 2GHz. The minimum detectable electric field strengths are 2.85×10-3V/m at 100MHz and 8.91×10-4V/m at 2GHz. Therefore, the optical electric field sensor made by LiNbO3 could become more valuable in application.
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Chung, Kuo-Fang, and 鍾國方. "Optimization of bandwidth of Si-Based Lateral Junction Traveling Wave Mach-Zehnder Modulator by using Genetic Algorithm." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/kuzk3p.
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碩士國立臺灣大學
光電工程學研究所
107
With the bloom of big data, Internet of things, and cloud computing in recent years, the need for the speed of data transmission is increasing. Thus, datacenters and the related transmission capacity have become important. Fortunately, the silicon photonic optical interconnect featuring large transmission capacity and long transmission distance is very suitable for the inter- and intra- datacenter data transmission. Leveraging the advantages of mature fabrication technology, low cost, and mass production from the Complementary Metal Oxide Semiconductor (CMOS) manufacturing technology, the Silicon Photonics platform has become the leading option for the mid- and short- range transmission for the datacenters. Therefore, this thesis aims at the analysis and optimization of the Si-Based Traveling Wave Optical Modulator used in an optical interconnect transmitter based on the CMOS-compatible fabrication technology and the background realm of Silicon Photonics. With the considerations of the CMOS fabrication technology and the mask rule from IMEC and with the assumption of multiple unchangeable parameters, the thesis analyzed various parameters affecting Si-Based Lateral Junction Traveling Wave Mach-Zehnder Modulator (Si-Based LATWMZM) and discussed various device performances with the use of the modified attenuation-considered figures of merit including modulation efficiency, insertion loss IL, and extinction ratio ER, as well as the overlap integration between the electric field extracted from FDE solver in Lumerical MODE Solution and the analytical carrier density approximation of the reversed-biased P-N junction. In addition, by using the user-defined genetic algorithm, the performance of the device operating at the optical wavelength 1310 nm was optimized. Also, the discussion and the E-O bandwidth optimization of the two different cases with radio-frequency peak-to-peak voltages 2.5 Vpp and 3.5 Vpp were made under the constraints of ER >= 5.5 dB and SEE11 <= -9 dB. The optimization results show that the E-O bandwidth and the modulation efficiency for 2.5 Vpp and 3.5 Vpp are (56 GHz, 1.12 V-cm) and (67 GHz, 1.26 V-cm) respectively. After the optimization, the validations of eye diagrams both with ER > 9 dB were simulated by Lumerical Interconnect. In the last part, the thesis analyzed the tolerance of the device to the fabrication error. The results showed that the possible reductions of BW and ER are about 10 GHz and 0.5 dB respectively for a uniform fabrication error of 20 nm.
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Yu-ChangHe and 何侑昌. "On Image Objects Phase/Amplitude Measurements and Resolution Enhancement Using Conjugated-Spatial Light Modulator in Mach-Zehnder Interferometer." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/90469749767117753524.
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碩士國立成功大學
電腦與通信工程研究所
100
Mach-Zehnder interferometer is used to make lights interference and acquire the parameter characteristic of lights. We can equip optical device with Mach-Zehnder interferometer and arrange these optical device appropriately to do many applications. In the thesis, we present two applications. One is the measurement of the amplitude and phase of the light of a signal arm. The other is the resolution enhancement of object samples utilizing spatial light modulators. In the first application, we utilize spatial light modulators and linear polarizers to measure the amplitude and phase of the light of a signal arm in Mach-Zehnder interferometer. We classify two cases： one is the transfer function of device under test in signal arms being a constant, and the other is the transfer function of device under test not a constant. If it is the first case, we use simpler scheme and utilize spatial light modulators to realize the phase measurement. However, if it is the other case, we use more complicated scheme and arrange linear polarizers to measure the phase and amplitude. We also combine spectrometer and charge coupled device with computers to compute the phase and amplitude. In the second application, we enhance the resolution of object samples. By observing interference properties, we find that the scheme equipped with spatial light modulators can detect sick signs or tumor in object samples easier. If we can totally merge it into image signal processing, it could be widely used in medical field. Additionally, it also could be used in industrial field to detect some quantity.
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You, Chao-Yuan, and 游朝元. "Fabrication of Mach-Zehnder Electro-Optic Modulator for Blue-Laser Wavelength Using Magnesium-Oxide-Induced Lithium-Outdiffused Waveguide." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/22755274219288040867.
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碩士國立臺灣大學
光電工程學研究所
95
In this study, magnesium-oxide-induced lithium-outdiffusion (MILO) method is used to fabricate Mach-Zehnder electro-optic modulators on z-cut lithium niobate substrate for a blue laser source of wavelength 473nm. Similar devices fabricated by traditional annealed-proton-exchanged (APE) method are also prepared for comparison. Experimental data show that an MILO waveguide of width 3.2μm supports only single-mode when it is fabricated by sputtering a MgO thin-film of thickness 500Å and then diffusing at 1000°C for 30 min. Mach-Zehnder electro-optic modulator composed of MILO waveguide for blue-laser wavelength is demonstrated. Its halfwave voltage and extinction ratio are found to be 4.0V and 7dB, respectively, which are better than those fabricated by the APE method. Photorefractive effect on Mach-Zehnder electro-optic modulator is measured. Experimental results show MILO waveguides are found less-resistant to the photorefractive effect, although Mach-Zehnder modulators with MILO waveguides have been successfully fabricated.
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Lin, Hsiu-Sheng, and 林修聖. "Study and Design on Employing Single Mach-Zehnder Modulator with Optical Phase Conjugation Configuration for DWDM Long Haul Transmission System." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/2z6949.
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博士國立臺北科技大學
電腦與通訊研究所
99
The optical communication system developed into a high speed and high capacity Dense Wavelength Division Multiplexing (DWDM) system employing a modulation format which has an effective scheme to reduce signal impairments producing nonlinear effects, amplified spontaneous emission and dispersion phenomenon. The return to zero differential phase shift keying (RZ-DPSK) modulation format in DWDM optical communication system provides greater dispersion immunity, a narrow spectrum width, lower nonlinear effect, a simple scheme and reduces cost effectively. In the dissertation, we proposed and demonstrated the 48 x 40 Gb/s DWDM system scheme employing single Mach Zehnder Modulation (MZM) RZ-DPSK modulation format with hybrid Raman/EDFA configuration to improve transmission signal, and employing an OPC configuration in the middle line that can compensate for dispersion impairment and improve nonlinear effects to investigate transmission distance performances. We proposed a novel scheme to generate an RZ-DPSK Signal, which needs only one MZM and the use of an electronic component to replace the pulse carving in a conventional second MZM that effectively reduces the modulation system complex at a lesser cost. The 48 x 40 Gb/s DWDM system scheme employing single MZM RZ-DPSK modulation format and hybrid Raman/EDFA configuration using SMF with DCF and LEAF with RDF have a transmission of 27 spans over 3240 km and 28 spans over 3360 km, respectively. In the middle of the transmission distance employing Optical Phase Conjugation (OPC) configuration, after SOA device by the Four Wave Mixing (FWM) effect, the power signal promotes 13 dB. The increased power can compensate for the accumulated dispersion impairment and improve nonlinear effects. Therefore, the 48 x 40 Gb/s DWDM system scheme using SMF with DCF for the fiber transmission section and LEAF with RDF for the fiber transmission section employing OPC configuration in the middle line, the transmission distance increased by 55% and 64.2%, respectively. The proposed 48 x 40 Gb/s DWDM system scheme successfully employs single MZM RZ-DPSK modulation format to reduce modulation complex configuration and employs hybrid Raman/EDFA configuration to promote the power signal. In the middle line employing OPC configuration that can compensate for dispersion impairment, improve nonlinear effects, and promote power optical spectrum signal for long haul optical transmission.
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Lee, Hao-Ti, and 李豪隄. "A Double-Transmission-Capacity Optical Transmitter by using a Mach-Zehnder External Modulator with Different Signals Modulated under Two Orthogonal Polarrization States." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/92136080553737812937.
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碩士國立臺灣科技大學
電子工程系
89
IP and Gigabit Ethernet are the most common trend in data communication. But several problems exists. IP over DWDM needs to deal with control channel and baseband channel in the same wavelength. GBIC of Gigabit Ethernet has two port fibers for communication, but using one fiber is much better for the cost. In this thesis, we propose a novel E/O modulator architecture for solving these problems. With this new E/O modulator, two RF signals are modulating a same light but under two different polarization states. Hence, the bandwidth is doubled. And it is based on MZI structure. We analyze the light wave which is propagating in crystal and let the coupling effects are disappeared. In order to understand the light wave aracteristics and field distribution, we find the analytic solutions from lane wave and Gaussian beam in the crystals. In non-ideal case, the cascade of crystals in a path have serious leakage field upling. Besides, the light wave in waveguide is not propagating along z-axis but a small angle from it, therefore, polarization states are coupling. A finite difference method is used to the wave equation numerically.