Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Apresenta-se neste trabalho um estudo de produção difrativa de pares tt, na topologia de dupla troca de pómeron (DPE) inclusiva, nas condições do CMS para alta luminosidade (2 x 1033 cm-2s-1). O canal de decaimento para o sistema tt é o Semi-Leptônico, comum quark × top decaindo em um jato de b, um múon e um neutrino e o outro em jatos, sendo um deles de b (tt → bbqqμνμ). O processo acima foi simulado com o gerador DPEMC v2.4 [12], juntamente com o código de simulação FAMOS [41], versão 1.4.0, do CMS. Dois modelos teóricos foram utilizados, aqueles de Cox & Forshaw [10], [11] e de Boonekamp, Peschanskie Royon [13], [14]. Como background dominante, temos a combinação de um evento de tt não difrativo com eventos de pile-up (em média7) na mesma colisão de feixe no LHC. Como utilizam-se Roman Pots) para selecionar os eventos difrativos, eventos não ocorre relacionados de pile-up gerando prótons próximos à linha do feixe juntamente com um evento de tt não difrativo, são indistinguíveis experimentalmente do caso difrativo. Para uma luminosidade integrada de 10 fb-1, obtém-se da ordem de centenas de eventos para este background, enquanto que de O(1)a O (100) eventos do sinal difrativo, dependendo do modelo teórico utilizado. / Inclusive DPE (double pomeron exchange) production of t pairs was studied for CMS high luminosity running (2 x 1033cm-2s-1 ), with one top decaying into a b-jet, a muon and a neutrino, and the other to jets, one of them a b-jet (bbqqμνμ). The process was simulated with the generator DPEMC v2.4 [12], together with the fast CMS simulation code FAMOS [41], version 1.4.0. Two theoretical models were used for this analysis, that of Cox & Forshaw [10], [11] and of Boonekamp, Peschanski and Royon [13], [14]. As dominant background, we have the overlap of a non-diffractive tt event with pile-up events (7 in average) in the same bunch crossing. Since we use Roman Pots to tag the diffractive event, uncorrelated diffractive pile-up events generating very forward diffractive protons can fake the non-diffractive event as a diffractive one. For an integrated luminosity of 10 fb-1 we obtain a number of events of O (100) for this background, while (1) to O (100) for the diffractive signal, depending on the theoretical model used.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Apresenta-se neste trabalho um estudo de produção difrativa de pares tt, na topologia de dupla troca de pómeron (DPE) inclusiva, nas condições do CMS para alta luminosidade (2 x 1033 cm-2s-1). O canal de decaimento para o sistema tt é o Semi-Leptônico, comum quark × top decaindo em um jato de b, um múon e um neutrino e o outro em jatos, sendo um deles de b (tt → bbqqμνμ). O processo acima foi simulado com o gerador DPEMC v2.4 [12], juntamente com o código de simulação FAMOS [41], versão 1.4.0, do CMS. Dois modelos teóricos foram utilizados, aqueles de Cox & Forshaw [10], [11] e de Boonekamp, Peschanskie Royon [13], [14]. Como background dominante, temos a combinação de um evento de tt não difrativo com eventos de pile-up (em média7) na mesma colisão de feixe no LHC. Como utilizam-se Roman Pots) para selecionar os eventos difrativos, eventos não ocorre relacionados de pile-up gerando prótons próximos à linha do feixe juntamente com um evento de tt não difrativo, são indistinguíveis experimentalmente do caso difrativo. Para uma luminosidade integrada de 10 fb-1, obtém-se da ordem de centenas de eventos para este background, enquanto que de O(1)a O (100) eventos do sinal difrativo, dependendo do modelo teórico utilizado. / Inclusive DPE (double pomeron exchange) production of t pairs was studied for CMS high luminosity running (2 x 1033cm-2s-1 ), with one top decaying into a b-jet, a muon and a neutrino, and the other to jets, one of them a b-jet (bbqqμνμ). The process was simulated with the generator DPEMC v2.4 [12], together with the fast CMS simulation code FAMOS [41], version 1.4.0. Two theoretical models were used for this analysis, that of Cox & Forshaw [10], [11] and of Boonekamp, Peschanski and Royon [13], [14]. As dominant background, we have the overlap of a non-diffractive tt event with pile-up events (7 in average) in the same bunch crossing. Since we use Roman Pots to tag the diffractive event, uncorrelated diffractive pile-up events generating very forward diffractive protons can fake the non-diffractive event as a diffractive one. For an integrated luminosity of 10 fb-1 we obtain a number of events of O (100) for this background, while (1) to O (100) for the diffractive signal, depending on the theoretical model used.

AutoCAD, Zemax Optic Studio 15, and Interactive Data Language (IDL) with the Proper Library are used to computationally model and test a diffractive mask (DiM) suitable for use in the Gemini Multi-Conjugate Adaptive Optics System (GeMS) on the Gemini South Telescope. Systematic errors in telescope imagery are produced when the light travels through the adaptive optics system of the telescope. DiM is a transparent, flat optic with a pattern of miniscule dots lithographically applied to it. It is added ahead of the adaptive optics system in the telescope in order to produce diffraction spots that will encode systematic errors in the optics after it. Once these errors are encoded, they can be corrected for. DiM will allow for more accurate measurements in astrometry and thus improve exoplanet detection. The mechanics and physical attributes of the DiM are modeled in AutoCAD. Zemax models the ray propagation of point sources of light through the telescope. IDL and Proper simulate the wavefront and image results of the telescope. Aberrations are added to the Zemax and IDL models to test how the diffraction spots from the DiM change in the final images. Based on the Zemax and IDL results, the diffraction spots are able to encode the systematic aberrations.

In conventional optics, curved lenses focus light rays to a focal point after light passes through them. These lenses have been designed to shape the wavefront of the incident beam as it emerges from the curved surface of the lens. Conventional lenses suffer from many limitations, such as limited optical quality for imaging and integration difficulties with other optical components due to their large size, huge thickness, as well as being difficult to manufacture. Using subwavelength structure, it is possible to fabricate flat, thin lenses (metalenses) with new optical properties not found in nature, in which many fundamental properties of light (like polarization, focal point, and phase) can be controlled with high accuracy. This results in high resolution and high quality of optical imaging. This thesis demonstrates a new design of reflective metalens, in which the metalens structure is integrated with another optical component: Distributed Bragg Reflector (DBR). The metalens planer is a two-dimensional ultrathin planer arranged as an array with subwavelength separation distance. In recent works, a metalens was integrated with (metal/dielectric)-mirrors to form reflective metalenses. Simulation results show that, high-focusing efficiency is obtained for the lens (> 60%) with the ability to reflect96% of total incident optical power. In comparison, the new metalens-DBR design - processes maintain the same high-focusing efficiency, but with a reflectance of 99.99%, which makes it promising for optoelectronic integration and perfectly suitable for integration with Vertical Cavity Surface Emitting Lasers (VCSEL) technology. This study of the optical properties: focal length; optical aberration; insensitivity to light polarization; and focusing efficiency of demonstrated metalens was done mainly by Finite Difference Time Domaine (FDTD) by using Lumerical FDTD solution.

This dissertation investigates the monolithic integration of dual optical elements on high power semiconductor lasers for emission around 980nm wavelength. In the proposed configuration, light is coupled out of the AlGaAs/GaAs waveguide by a low reflectivity grating coupler towards the substrate where a second monolithic optical element is integrated to improve the device performance or functionality. A fabrication process based on electron beam lithography and plasma etching was developed to control the grating coupler duty cycle and shape. The near-field intensity profile outcoupled by the grating is modeled using a combination of finite-difference time domain (FDTD) analysis of the nonuniform grating and a self-consistent model of the broad area active region. Improvement of the near-field intensity profile in good agreement with the FDTD model is demonstrated by varying the duty cycle from 20% to 55% and including the aspect ratio dependent etching (ARDE) for sub-micron features. The grating diffraction efficiency is estimated to be higher than 95% using a detailed analysis of the losses mechanisms of the device. The grating reflectivity is estimated to be as low as 2.10-4. The low reflectivity of the light extraction process is shown to increase the device efficiency and efficiently suppress lasing oscillations if both cleaved facets are replaced by grating couplers to produce 1.5W QCW with 11nm bandwidth into a single spot a few mm above the device. Peak power in excess of 30W without visible COMD is achieved in this case. Having optimized, the light extraction process, we demonstrate the integration of three different optical functions on the substrate of the surface-emitting laser. First, a 40 level refractive microlens milled using focused ion beam shows a twofold reduction of the full-width half maximum 1mm above the device, showing potential for monolithic integration of coupling optics on the wafer. We then show that differential quantum efficiency of 65%, the highest reported for a grating-coupled device, can be achieved by lowering the substrate reflectivity using a 200nm period tapered subwavelength grating that has a grating wavevector oriented parallel to the electric field polarization. The low reflectivity structure shows trapezoidal sidewall profiles obtained using a soft mask erosion technique in a single etching step. Finally, we demonstrate that, unlike typical methods reported so far for in-plane beam-shaping of laser diodes, the integration of a beam-splitting element on the device substrate does not affect the device efficiency. The proposed device configuration can be tailored to satisfy a wide range of applications including high power pump lasers, superluminescent diodes, or optical amplifiers applications.

No description available.

Ces travaux de thèse ont pour but d’analyser les outils de photolithographies permettant d’inscrire des réseaux des diffractions et d’identifier ceux qui sont suffisamment flexibles pour être adapté à des substrats non conventionnels tel que des cylindres ou des tubes. Les outils de photolithographies développés ont aussi été ajustés afin d’inscrire directement un réseau de diffraction dans une couche fonctionnelle de TiO2, apporté par la voie sol-gel. Cette thèse est une étude prospective car la périodicité ou le motif des structures diffractantes inscrites n’ont pas été définis pour une application spécifique. Deux outils de photolithographies ont été adaptés avec succès aux substrats cylindriques. Ils seront présentés ici et s’accompagneront d’une perspective en vue d’une application particulière. Enfin, le dernier chapitre se distincte des précédents car il ne porte pas sur le développement d’un outil de photolithographie mais sur la transformation chimique du TiO2 (diélectrique) en TiN (métal), il reste néanmoins dans la continuité de ses travaux de thèse car cette transformation est adaptée à tous types de substrats / The aim of this thesis is to analyze the photolithography tools used to print diffraction gratings and to identify those that are sufficiently flexible to be adapted to unconventional substrates such as cylinders or tubes. The photolithography tools developed have also been adjusted in order to write directly a diffraction grating in a functional layer of TiO2, supplied by the sol-gel pathway. This thesis is a prospective study because the periodicity or the pattern of the registered diffracting structures has not been defined for a specific application. Two photolithography tools have been successfully adapted to cylindrical substrates. They will be presented here and will be accompanied with a perspective for a specific application. Finally, the last chapter is distinct from the previous ones because it does not concern the development of a photolithography tool but on the chemical transformation of TiO2 (dielectric) into TiN (metal), it nevertheless remains in the continuity of its thesis because this transformation is adapted to all types of substrates

Orientador: Jose Joaquin Lunazzi / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-08-08T07:18:00Z (GMT). No. of bitstreams: 1 RodriguezRivera_NoemiInes_D.pdf: 6088514 bytes, checksum: c2c66dc6b71f900d00c6832f96aaf3eb (MD5) Previous issue date: 2007 / Resumo: Apresentamos neste trabalho a análise da formação de imagens por elementos difrativos com luz branca fazendo o traçado de raios pelas direções principais. O primeiro sistema analisado é composto por duas redes de difração e uma fenda, o segundo por dois elementos bidimensionais de estrutura espiral e um orifício, que formam imagens ortoscópicas (relevo natural). A partir das análises mencionadas desenvolvemos um sistema de dois elementos difrativos sem elementos intermediários que forma uma imagem de luz branca que é pancromática, porque oferece as cores originais. Além disso, apresentamos um sistema formador de uma imagem por transmissão que consiste na projeção de objetos usando uma fonte linear (filamento extenso) e um elemento difrativo. Aproveitando as propriedades de uma fonte linear, desenvolvemos um sistema que permite que espelhos ou lentes imperfeitos gerem imagens nítidas. Mediante estes sistemas visamos conseguir um dia a formação de imagens convergentes, entretanto já oferecemos novas maneiras de se exibir imagens tridimensionais atrativas e amplas / Abstract: We present the analysis of the formation of images by diffractive elements using white light by performing ray-tracing through main directions. The first system we describe is composed of two diffraction gratings and a slit, the second by two bi-dimensional spiral elements and a hole aperture, generating ortoscopic (natural relief) images. From this we had found a system of two diffractive elements without any intermediating element that makes and image which is panchromatic because gives original colors. Furthermore, we present a transmission imaging system that projects objects by means of a linear source (extended filament) and a diffractive element. Profiting the imaging properties of that linear source we also developed a system for mirrors and lenses having no sharpness to generate sharp images. By studying these systems we seek to find a way to achieve the making of convergent images and we already offer new ways to exhibit attractive and large three-dimensional images / Doutorado / Física / Doutor em Ciências

In this thesis, two studies of the diffractive phenomena in the electron proton collisions with the H1 detector at HERA are presented.<p>The first is the study of the inclusive elastic diffractive events $ep \ / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Actuellement, la presbytie peut être corrigée chirurgicalement à l’aide d’implants intraoculaires réfractifs ou diffractifs multifocaux (chirurgie endoculaire invasive et irréversible) ou en intracornéen avec une correction multifocale réfractive (correction laser irréversible, ou insertion d’un implant dans le stroma). L’objectif de ce travail est de développer un nouvel implant permettant de corriger la presbytie, qui allie l’innocuité et la réversibilité d’une correction intracornéenne, à l’efficacité du diffractif. Le design des profils optiques bifocaux a été permis grâce au développement d’outils de simulation optique. Les efficacités de diffraction sont calculées à partir de la propagation du champ électrique par spectre angulaire. La qualité optique est déterminée d’après les simulations de Fonction de Transfert de Modulation obtenues sous Zemax. Des simulations de rendu d’images permettent de visualiser les effets de différents profils envisagés. Les paramètres critiques du design optique sont déterminés. Le choix du matériau dépend des contraintes de biocompatibilité de l’implant et des techniques de fabrication. La solution retenue est un hydrogel à forte teneur en eau, couplé à une nouvelle architecture de l’implant. L’hydrogel est obtenu par polymérisation radicalaire de macromonomères difonctionnels de poly(éthylène glycol) de masses molaires de l’ordre de 8000 g.mol‐1 qui conduisent à des propriétés mécaniques et une perméabilité aux nutriments compatibles avec l’application. La réalisation, la stérilisation et la caractérisation optique de prototypes ont abouti à la preuve du concept d’un implant bifocal diffractif intracornéen / Presbyopia can be corrected with surgery by means of refractive or diffractive multifocal intraocular lenses (which imply an irreversible and invasive endocular surgery) or by intracorneal multifocal refractive correction (irreversible laser correction, or insertion of an intrastromal implant). This work aims at developing a new implant to correct presbyopia, which takes advantage of both the harmlessness and the reversibility of an intracorneal correction, and the efficiency of diffractive optics. The design of the bifocal optical profiles was based on the development of optical simulation tools. The diffractive efficiencies are calculated from the distribution of the electric field with the method of angular spectrum. The optical quality is determined according to the simulations of Modulation Transfer Function obtained with Zemax. Images simulations show the effects of the different profiles studied. The critical parameters of the optical design are also determined. The choice of the material depends on several constraints such as biocompatibility and techniques of manufacturing. The adopted solution relies on the used of an hydrogel with high water content and the design of a new implant architecture. The hydrogel is obtained by radical polymerization of difunctional macromonomers of poly(ethylene glycol) with molar masses around 8000 g.mol‐1, allowing mechanical properties and permeability to nutriments compatible with the application. The realization, the sterilization and the characterization of prototypes showed the proof of the concept of a diffractive bifocal intracorneal implant