Femtosecond laser has been an essential tool for nonlinear optics and materials processing at micrometer scale, in which chalcogenide and heavy metal oxide glasses have received special attention not only for their high third-order optical nonlinearities but also due to their transparency up to the infrared regions. Although metallic nanoparticles are expected to improve the optical properties of glasses, there are no enough experimental researches about their influence on the nonlinear refractive index (n2) and nonlinear absorption coefficient (&#946), moreover at femtosecond regime. Based on the scientific and technological interests on highly nonlinear glasses, the goal of this thesis was to apply femtosecond laser pulses in two main domains: (i) at the basis of fundamental science, to study the effect of metallic nanoparticles in the third-order nonlinear optical properties of glasses; and (ii) at the field of applied science, aiming the development of photonic devices, performed by the fabrication of 3D optical waveguides containing metallic nanoparticles. This aim was achieved through the techniques of z-scan and femtosecond laser micromachining, which provided the nonlinear optical characterization and waveguides development, respectively. First, we analyzed the third-order nonlinear optical properties of the GeO2-Bi2O3 glass containing gold nanoparticles, which promoted saturation of the absorption in the region of the surface plasmon resonance band. On the other hand, these gold nanoparticles did not affect the n2 that kept constant in the wavelength range of 480 - 1500 nm. The same features were investigated for a Pb2P2O7-WO3 matrix doped with copper nanoparticles. In contrast to the gold doped ones, these samples showed a slight enhancement of the nonlinear refractive index when the energy of the excitation approaches the surface plasmon band. We also found out that the Pb2P2O7-WO3 matrix is a good host to grow silver nanoparticles by fs-laser micromachining. Similarly, copper nanoparticles were produced in a borosilicate glass using single-step laser processing. The explanation for metallic nanoparticle formation is addressed in this thesis, as well as, its application in waveguides. Thus, we demonstrated the functionality of optical waveguides containing Cu0 or Ag0 nanoparticles. Still based on the technological interests on glasses doped with nanoparticles, we showed a single-step synthesis of silver sulfide nanoparticles in chalcogenide glass, which was carried in partnership with researches at Princeton University. The materials investigated in this PhD work are of great importance for photonics, in which the synthesis of nanoparticles, fabrication of waveguides and nonlinear optical characterization have been performed. / O laser de femtossegundos tem sido uma ferramenta essencial tanto para a óptica não-linear quanto para o processamento de materiais na escala micrométrica, na qual os vidros calcogenetos e óxidos de metais pesados têm recebido atenção especial, não apenas pelas suas elevadas não-linearidades ópticas de terceira ordem, mas também devido à sua transparência até o infravermelho. Embora seja esperado que nanopartículas metálicas melhorem as propriedades ópticas dos vidros, não existe investigações experimentais suficientes sobre a sua influência no índice de refração não linear (n2) e no coeficiente de absorção linear (&#946), sobretudo no regime de femtossegundos. Com base nos interesses científicos e tecnológicos de vidros altamente não-lineares, o objetivo deste trabalho foi aplicar pulsos laser de femtossegundos em dois domínios principais: (i) na campo da ciência fundamental, para estudar o efeito de nanopartículas metálicas nas propriedades ópticas não lineares de terceira ordem destes materiais; e (ii) no domínio da ciência aplicada, visando o desenvolvimento de dispositivos fotônicos, realizado pelo fabricação de guias de onda tridimensionais contendo nanopartículas metálicas. Este objetivo foi alcançado através das técnicas de varredura-z e microfabricação com laser de femtossegundos, que proporcionaram a caracterização óptica não-linear e o desenvolvimento de guias de onda, respectivamente. Primeiramente, foram investigadas as propriedades ópticas não-lineares de terceira ordem do vidro GeO2-Bi2O3 contendo nanopartículas de ouro, as quais promoveram saturação da absorção na região da banda de ressonância de plásmon. Por outro lado, essas nanopartículas não afetaram o n2, que se manteve constante no intervalo de comprimento de onda 480 - 1500 nm. As mesmas características foram investigadas para uma matriz Pb2P2O7-WO3 dopada com nanopartículas de cobre. Em contraste com os vidros dopados com ouro, estas amostras apresentaram um ligeiro aumento do índice de refração não linear quando a energia de excitação está próxima da banda de ressonância de plásmon. Observou-se ainda que a matriz Pb2P2O7-WO3 é ideal para a obtenção de nanopartículas de prata através da microfabricação com laser de femtossegundos. Similarmente, nanopartículas de cobre foram produzidas em vidro de borosilicato usando somente uma varredura a laser. A explicação para a formação de nanopartículas metálicas é abordada nesta tese, bem como sua aplicação em guias de onda. Deste modo, demonstrou-se a funcionalidade de guias de onda ópticos compostos por nanopartículas de Cu0 e Ag0. Ainda com base nos interesses tecnológicos em vidros dopados com nanopartículas, demonstrou-se uma síntese de nanopartículas de sulfeto de prata em vidro calcogeneto usando o processamento de única etapa, realizada em parceria com pesquisadores da Universidade de Princeton. Os materiais investigados neste trabalho de doutorado são de grande importância para aplicações em fotônica, em que a síntese de nanopartículas, a fabricação de guias de onda e a caracterização óptica não-linear foram realizadas.

Esta tese descreve métodos interativos para estimar e compensar erros de refração (NETRA) e opacidades ópticas (CATRA) em sistemas de imageamento usando telas de campos de luz programáveis, de alta resolução e alto contraste. Os novos métodos para oftalmologia computacional descritos aqui podem avaliar câmeras e olhos se o usuário do sistema estiver consciente do modelo de interação. A solução combina elementos ópticos baratos, interfaces interativas e reconstrução computacional. Uma tela de campos de luz, posicionada perto do olho, cria objetos virtuais em profundidades pré-definidas através de várias seções do olho. Via esta plataforma, cria-se uma nova gama de aplicações interativas que é extremamente sensível a aberrações ópticas. A capacidade de focar em um objeto virtual, alinhar padrões exibidos na tela e detectar suas variações de forma e brilho permite ao sistema estimar a função de propagação de ponto de luz para o olho e a acomodação da lente. Enquanto os sistemas convencionais requerem formação especializada, dispositivos caros, procedimentos de segurança sensíveis e normalmente não são móveis, esta tese simplifica o mecanismo, colocando o paciente no centro do teste. Ao final, a resposta do usuário calcula a condição de refração em termos de poderes esférico e cilíndrico, o eixo de astigmatismo, o poder de acomodação da lente e mapas para a opacidade, atenuação, contraste e função de espalhamento de um ponto de luz. O objetivo é permitir que o público em geral opere um sistema de iluminação portátil e obtenha uma compreensão de suas próprias condições visuais. Esta tese apresenta projetos ópticos para software e hardware para oftalmologia computacional. Avaliações com usuários e com câmeras com lentes modificadas são realizadas. Os dados compilados são usados para reconstruir visão afetada do indivíduo, oferecendo uma nova abordagem para capturar informações para o rastreio, diagnóstico e análises clínicas de anomalias visuais. / This thesis proposes light-field pre-warping methods for measuring and compensating for optical aberrations in focal imaging systems. Interactive methods estimate refractive conditions (NETRA) and model lens opacities (CATRA) of interaction-aware eyes and cameras using cost-efficient hardware apps for high-resolution screens. Tailored displays use stereo-viewing hardware to compensate for the measured visual aberrations and display in-focus information that avoids the need of corrective eyeglasses. A light-field display, positioned very close to the eye, creates virtual objects in a wide range of predefined depths through different sectors of the eye’s aperture. This platform creates a new range of interactivity that is extremely sensitive to spatially-distributed optical aberrations. The ability to focus on virtual objects, interactively align displayed patterns, and detect variations in shape and brightness allows the estimation of the eye’s point spread function and its lens’ accommodation range. While conventional systems require specialized training, costly devices, strict security procedures, and are usually not mobile, this thesis simplifies the mechanism by putting the human subject in the loop. Captured data is transformed into refractive conditions in terms of spherical and cylindrical powers, axis of astigmatism, focal range and aperture maps for opacity, attenuation, contrast and sub-aperture point-spread functions. These optical widgets carefully designed to interactive interfaces plus computational analysis and reconstruction establish the field of computational ophthalmology. The overall goal is to allow a general audience to operate portable light-field displays to gain a meaningful understanding of their own visual conditions. Ubiquitous, updated, and accurate diagnostic records can make private and public displays show information in a resolution that goes beyond the viewer’s visual acuity. The new display technology is able to compensate for refractive errors and avoid light-scattering paths. Tailored Displays free the viewer from needing wearable optical corrections when looking at it, expanding the notion of glasses-free multi-focus displays to add individual variabilities. This thesis includes proof-of-concept designs for ophthalmatic devices and tailored displays. User evaluations and validations with modified camera optics are performed. Capturing the daily variabilities of an individual’s sensory system is expected to unleash a new era of high-quality tailored consumer devices.

In recent years a new class of materials, the metamaterials, has emerged in the scientific community. The use of these materials makes possible to achieve unique electromagnetic properties, such as the negative refractive index. Today there exist several applications that take advantage of these special properties, such as sensors, antennas and invisibility cloaks, aiming at improving their intrinsic characteristics. Based on these considerations, this project aims at developing metamaterials structures to control the radiation properties of antennas in the microwave range, such as gain and directivity. More specifically, it was also chosen chiral metamaterials, mainly due to the phenomenon of electromagnetic field rotation which opens the possibility to control efficiently the radiation properties of antennas. In addition, chiral metamaterials, which have proved to be a more attractive alternative to obtain negative or zero refractive index, enable a greater degree of freedom in the design of different structures. This work encompasses all different phases of the structure design, namely: project, computational modeling, fabrication, and characterization of the proposed structures. We show improvements for the gain that in some cases reaches more than the double of the conventional monopole antenna gain and for the return loss parameter, which reaches minimum values. We also could maintain good efficiency and improve the input impedance matching. Finally, it is worth mentioning that this new technology also has the great potential to be applied in the telecommunication devices, particularly to improve communications based on antennas. / Nos últimos anos uma nova classe de materiais, os metamateriais, emergiu na comunidade científica. O uso desses materiais torna possível alcançar propriedades eletromagnéticas singulares, como o índice de refração negativo. Hoje existem vastas aplicações que usufruem destas propriedades especiais, como os sensores, mantas de invisibilidade e antenas, onde se procura o aperfeiçoamento de suas características intrínsecas. Com base nestas considerações, este projeto buscou desenvolver estruturas metamateriais para controle das propriedades de radiação de antenas na faixa de micro-ondas, tais como diretividade e ganho. Mais especificamente, foram utilizados os metamateriais quirais, principalmente devido ao fenômeno de rotação do campo eletromagnético que abre a possibilidade de controle mais eficiente das propriedades de radiação de antenas. Além disso, os metamateriais quirais, por se mostrarem uma alternativa mais atraente para se obter meios com índice de refração zero ou negativo, possibilitam um maior grau de liberdade no projeto de diferentes estruturas. Este trabalho contempla, ainda, todas as etapas de projeto de tais estruturas, quais sejam: projeto, modelagem computacional, fabricação, e caracterização das estruturas. Mostramos melhorias para o ganho que, em alguns casos, chega a mais do que o dobro do ganho da antena monopolo convencional e para o parâmetro de perda de retorno, que atinge valores mínimos. Nós também mantivemos uma boa eficiência e melhoramos o casamento de impedância de entrada. Finalmente, vale salientar que essa nova tecnologia também apresenta grande potencial de ser aplicada em dispositivos de telecomunicações, com o intuito de aprimorar a comunicação baseada em antenas.

[pt] Nanopartículas metálicas apresentam um pico no espectro de absorção devido ao efeito de LSPR (Localized Surface Plasmon Resonance – Ressonância de Plasmon de Superfície Localizado). A posição espectral do pico depende da forma, do tamanho, do material das nanopartículas e do índice de refração do meio em que se encontra. Conhecendo como a posição espectral deste pico varia de acordo com o índice de refração externo, pode-se utilizar, em princípio, estas nanopartículas como elemento sensor para medir a refração de líquidos e gases. Um sensor de índice de refração foi desenvolvido fabricando-se nanopartículas metálicas na extremidade de uma fibra óptica. Estas nanopartículas foram fabricadas a partir de um filme de ouro evaporado na extremidade de uma fibra óptica que depois foi aquecida. As nanopartículas assim formadas possuem uma distribuição não homogênea de forma e tamanho. De forma a se obter um maior controle do tamanho e da forma das nanopartículas metálicas fabricadas para o desenvolvimento de um sensor óptico com maior controle dos parâmetros, foi investigada nesta dissertação a formação de nanopartículas de prata por síntese química. Diferentes processos para a síntese foram investigados. As nanopartículas de prata localizadas na extremidade da fibra óptica foram caracterizadas quanto à resposta do sinal de LSPR quando as nanopartículas estavam em contato com meios com diferentes índices de refração. Visando ainda a investigação de sistemas de fibras ópticas com aplicação em sensoriamento, foi realizada uma simulação da deformação de cavidades elípticas formadas no interior de fibras ópticas quando estas estão sujeitas à aplicação de uma tensão longitudinal da fibra. Este tipo de cavidade pode ser usada como sensor de deformação devido à interferência das múltiplas reflexões no interior da cavidade. / [en] Metallic nanoparticles show a peak in the absorption spectrum due to the Localized Surface Plasmon Resonance (LSPR) effect. The position of this peak depends on the shape, size and the type of the nanoparticles as well as on the refractive index of the surrounding media. From the dependence of the position of the peak with the external refractive index, it is possible to use these nanoparticles as a sensor element to measure the refractive index of liquids and gas. A refractive index sensor was developed with nanoparticles deposited at the end face of an optical fiber. These nanoparticles, fabricated from a heated gold film deposited at the end face of the fiber, have a non homogenous distribution of size and form. In order to obtain a better control of the size and form of the fabricated metallic nanoparticles, aiming the development of an optical sensor with control of the involved parameters, it was investigated in this work the formation of silver nanoparticles by chemical synthesis. Furthermore, extending the investigation of fiber optics systems with applications on sensing, it was performed a simulation of the deformation of elliptical air cavities, formed in the interior of optical fibers, under the effect of longitudinal stress along the fiber. This type of system can be used as a deformation sensor due to the multiple interference reflections in the interior of the cavity.

Nonlinear optical microscopy is a collection of very powerful imaging techniques. Linear optical microscopes probe the refractive index and absorption, which both stem from the first-order linear electric susceptibility. Especially in biological tissue, the variation in the refractive index is often small and the tissue is, in many cases, transparant. Nonlinear optical microscopes on the other hand probe the nonlinear higher-order susceptibilities, which can be chemically sensitive, leading to the capability to achieve label-free imaging. Nonlinear optical microscopes have been in development for more than thirty years and they are based on numerous nonlinear optical processes. The ones I will concentrate on in this thesis are second harmonic generation (SHG), coherent anti-Stokes Raman scattering (CARS), and stimulated Raman Scattering (SRS). The first technique is commonly used to image collagen as those molecules have a particularly large second-order nonlinear susceptibility due to their chiral structure. CARS and SRS on the other hand are often used because they resonantly target vibrational resonances in molecules, giving rise to the aforementioned label-free imaging. Deep understanding of the nonlinear imaging process is crucial to the interpretation of the images these techniques produce. Computational tools are exceptionally suited for this task as they allow studying the electromagnetic field anywhere in the sample as well as the far-field, and one can change any of the material properties to study their effect. One such tool is finite-difference time-domain (FDTD) that our group developed for nonlinear optical microscopy simulations. It is a direct discretization of Maxwell's equation. While computationally costly, it does allow any arbitrary shaped sample to be simulated. The sample can have frequency dependent refractive indexes, and also nonlinear media with third-order nonlinearities such as Kerr media and Raman-active media, but also second-order nonlinearities for SHG. The code is designed in such a way that it can run on thousands of CPUs on a wide variety of compute cluster which allows our group to obtain nanoscale resolution. Another computational tool I use is the free-space Green's function solution to the Helmholtz equation, which can be used to calculate the Hertz vector in the frequency domain, both in the near- and far-field, based on the induced nonlinear polarization. The electric field is then calculated from this Hertz vector. This technique is much faster then FDTD and also allows for arbitrary shapes of the nonlinear electric susceptibility in the sample. However, it assumes a homogeneous refractive index throughout the entire spatial domain and requires complete knowledge of the input beam or beams that induce the nonlinear polarization. In this thesis, I use these tools to study the image formation process of various nonlinear optical processes mentioned earlier. For example, I study the effect of an inhomogeneous refractive index on the images produced by these microscopes. In literature the index of refraction is almost always assumed to be homogeneous, because, as mentioned before, the inhomogeneity of the refractive index is often small. However, I show that these small differences in the index of refraction can have a significant effect on the measured far-field intensity signal. For example, in SRS and CARS images, the measured signal can increase by an order of magnitude depending on the index mismatch and structure of the sample. Additionally, significant shifts in perceived position occur. Even nonresonant nonlinear signals can be evoked purely through a mismatch in linear refractive index. Computational modelling can also help reveal additional detail. As SHG is a coherent process, subwavelength information can be inferred through the phase information. Our experimental collaborators built an interferometric SHG (I-SHG) microscope for exactly that purpose. We used this to image collagen fibrils, which are all aligned in a parallel fashion. However, because collagen fibrils have a chiral molecular structure, they can point either ``up'' or ``down''. Using my Green's function simulations of the SHG imaging process of collagen fibrils, I was able to predict the standard deviation in the measured phase and link it to the orientation of collagen fibrils in the focal spot of the probing laser beam, even though the diameters are far below the minimum resolvable capabilities of the microscope. We found that the ``upwards'' fibrils make up 46--53% of the sample. Even with a normal SHG microscope that does not measures phase, additional subresolution information is obtainable. With our collaborators we measured the ratio of the forward SHG intensity signal to that in the backward direction and with my simulations, we are able to link this to the fibril diameters in collagen tissue. Thus we inferred that the fibril diameter increases as a function of tissue depth. Furthermore, a computational technique called ptychography is able to retrieve phase information without an interferometric reference beam. Additionally, it increases resolution to the theoretical limit, independent of the laser focal spot size, and corrects for distortions in the input beam as well. I have developed this technique for use with nonlinear optical microscopy and was able to show it is a viable alternative to I-SHG by imaging simulated rat tail tendon at the diffraction limit while retrieving the orientation of the fibrils through the phase of the SHG signal. I also implemented the algorithm for CARS, where the phase information can be used to greatly increase the signal-to-noise ratio by reducing the nonresonant background radiation that results from competing nonlinear optical processes. I showed an example of this by imaging a simulated fibroblast cell where the CARS process was tuned to the lipid droplets inside of the cell. I am currently in talk with experimentalists to apply this theoretical technique to experiments as that would further demonstrate the impact of my work. Finally, keeping in theme with the collagen fibrils, I show that the ratio of the forward SHG signal to the backward signal, the F/B ratio, is affected by a mismatch in the refractive index for fibrils larger than 100nm. This measure is an indicator of fibril diameter and thus important for making qualitative predictions. Single fibrils are generally too small to be significantly affected by near-field effects, but the bigger fibrils can be. Fibrils in rat tail tendon have a distribution of fibrils diameters and the large fibrils occur infrequent. However, I found that the large fibrils are largely responsible for the forward as well as backward signal, thus refractive index mismatches still affect the F/B ratio significantly despite their infrequency. The F/B ratio for a collection of fibrils placed in a n=1.47 medium was found to be 31.8±0.7% higher than for those in a n=1.33 medium. Our experimental colleagues have done preliminary measurements on mouse tail tendon where they found an increase of 40±20%, in line with the value of 28.1±0.6% that I found for simulations with mouse tail tendon. In conclusion, the theoretical tools I have used in my thesis have provided me with the ability to study nonlinear optical image formation processes with a level of detail that would be near-impossible to do experimentally. I have used this ability to show how refractive index mismatches, such as those found in biological tissue, can significantly distort the far-field intensity signals. I have shown this for SRS and CARS where the far-field intensity signal appeared an order-of-magnitude larger compared to the same sample without a refractive index mismatch with the background medium. Additionally, shifts in the perceived position of the object under investigation were observed and I showed the presence of a nonresonant background signal in AM-SRS. Likewise I showed that in the SHG imaging of collagen fibrils significant changes in the F/B ratio can occur. All of these effects have important implications as these types of images as biomedical researches rely on the correct interpretation of nonlinear optical microscopy images for both research and diagnostics. Apart from showing the effect of a refractive index mismatch, I have also shown that computation modelling can be used to infer subwavelength features in SHG imaging experiments of collagen fibril such as fibril orientation and fibril diameter. These methods have the potential to aid medical researchers as changes in the structure of collagen are often an early indicator of diseases such as osteoarthritis. Finally, I showed that the ptychography algorithm I developed for nonlinear optical microscopy is able to retrieve phase information of the nonlinear electric susceptibility in SHG and CARS imaging while also enhancing the resolution and correcting for distortions in the input beams. I can also use much larger laser spot sizes than in conventional experiments without compromising the obtained resolution, thus fewer measurements are required. The technique is not limited to SHG and CARS either; it will work for other nonlinear optical processes as well. Experimental verification of nonlinear ptychography will be done soon. This technique has to potential to significantly improve current imaging techniques since access to the phase information allows one to observe additional information about the sample as we showed with the I-SHG microscope.

Quarto de Despejo, diário escrito por Carolina Maria de Jesus, foi lido e discutido em treze idiomas, dentre eles o francês. A história da mulher negra e semianalfabeta que viveu na favela do Canindé, em São Paulo, foi divulgada pela primeira vez na França em 1962 sob o título de Le Dépotoir. Publicado no Brasil em 1960, após revisão do jornalista Audálio Dantas, Quarto de Despejo, tal qual os leitores o conheceram, em muito se difere dos manuscritos da autora. Apesar de sua pouca alfabetização dois anos de escola Carolina, graças ao gosto pela leitura cultivado desde a infância, deu vida a uma obra cujas páginas revelam uma linguagem singular: aos seus erros de ortografia e sintaxe, a escritora alia um vocabulário rebuscado. Na transposição dos manuscritos ao livro publicado, Dantas substituiu quase todos os termos cultos da autora por correspondentes coloquiais no intuito de reforçar o estereótipo da favelada que escreve. Ou seja, no trabalho de edição do Quarto houve a atuação de uma ideologia que buscou influenciar o modo como o público veria Carolina e leria seu diário. Andre Lefevere, em Mother courages cucumbers : text, system and refraction in a theory of literature (1982), explica que a refração é a adaptação de uma obra literária para um público diferente, com a intenção de influenciar a forma como o público lerá a obra. Nesse sentido, a tradução é indicada pelo autor como um tipo de refração. Partindo do pressuposto de que o livro publicado no Brasil constituiu uma refração do verdadeiro texto de Carolina, e de que, segundo Lefevere, o processo de refração se manifesta na tradução, as publicações do diário caroliniano em diferentes idiomas difundiram pelo mundo uma imagem ainda mais refratada da autora e de seus escritos. Nosso objetivo é, pois, analisar o texto de Le Dépotoir a partir da noção lefeveriana de refração, a fim de mostrarmos como a imagem de Carolina e de sua vida no Canindé foram refratadas no original e, consequentemente, no diário traduzido. / Quarto de Despejo, diary written by Carolina Maria de Jesus, has been read and discussed within thirteen languages, French among them. The history of a semi-illiterate black woman who lived in the slums of Canindé, in São Paulo, was divulged for the first time in France in 1962 and entitled Le Dépotoir. Published in Brazil in 1960, after being revised by the journalist Audálio Dantas, Quarto de Despejo, just as its readers recognise it, mostly differs from the authors writings. Despite her low-rated literacy two years in school Carolina, inspired by a taste for reading since her childhood, brought life up to a piece of work in which pages unveil singular language: the writer allies laboured vocabulary to spelling and syntax mistakes. On the transposition of her writings to the publishing, Dantas substituted almost every formal terms used by the author for informal terms with a view to reinforcing the slum writing stereotype. In other words, there has been an ideological act on the edition of Quarto so as to influence the way the public would see Carolina and would read her diary. Andre Lefevere, in Mother courages cucumbers: text, system and refraction in a theory of literature (1982), explains that refraction is the adaptation of a certain literary work to a different public, so as to influence the way this public will read the book. According to that, the translation is suggested by the author as a kind of refraction. Having as an idea that the book published in Brazil is considered a refraction of Carolinas real text, and, according to Lefevere, that the refraction process is manifested in the translation, Carolinas diary publications in different languages disseminated throughout the world an even refracted image of the author and her writings. We aim to analyse the text in Le Dépotoir based on Lefeveres notions of refraction with a view to showing how Carolinas image and her life in Canindé have been refracted into the original text and consequently into the translated diary.

<p>Stopa prematuriteta konstantno raste, a sve vi&scaron;e prevremeno rođenih beba koje prežive neonatalni i perinatalni period zahteva adekvatno sistemsko i oftalmolo&scaron;ko praćenje i tretman. Prematuritet sam po sebi, predstavlja rizik za razvoj vida. Taj rizik dodatno povećava prisustvo prematurne retinopatije i refraktivnih mana. Skrining i tretman promena na retini u sklopu prematuriteta, kao i optička korekcija refraktivnih mana obezbeđuju uslove za razvoj vida. Cilj ovog istraživanja je bio utvrditi promene biometrijskih karakteristika oka prematurusa, sa i bez prematurne retinopatije, tokom &scaron;estogodi&scaron;njeg praćenja, utvrditi refraktivni status ove dve grupe dece sa &scaron;est godina, te povezati promene biometrijskih karakteristika oka sa refrakcijom. U ispitivanje je uključeno 192 prevremeno rođena deteta (384 oka). Vr&scaron;ena su tri pregleda, u uzrastu od 3 meseca, 12 meseci i 6 godina starosti. Nakon prvog pregleda ispitivani uzorak je, u zavisnosti od nalaza na očnom dnu, podeljen na bebe sa prematurnom retinopatijom i bebe bez ovog oboljenja, a kako bi se uporedile proučavane karakteristike. U sva tri navedena uzrasta je pregledano očno dno i merene su tri glavne biometrijske karakteristike koje utiču na refraktivni status: aksijalna dužina oka, dubina prednje očne komore i debljina očnog sočiva. Sa &scaron;est godina je određena refrakcija, uključujući zakrivljenost rožnjače odnosno kornealni astigmatizam, vidna o&scaron;trina bez korekcije refraktivne mane, a zatim i nakon korekcije. Ostali neophodni podaci su dobijeni iz medicinske dokumentacije. Pokazano je da prematurna retinopatija utiče na refraktivni status i vidni ishod sa &scaron;est godina, pre svega uticajem na zakrivljenost rožnjače, aksijalnu dužinu oka i dubinu prednje očne komore, dok su promene debljine očnog sočiva bez posebnog značaja. Vidne o&scaron;trine oba oka u pred&scaron;kolskom uzrastu prevremeno rođene dece sa prematurnom retinopatijom su statistički značajno manje kada se uporede sa vidnim o&scaron;trinama prevremeno rođene dece bez retinopatije, ali razlika u ovim dvema vrednostima gubi statističku značajnost nakon optičke korekcije. Učestalost astigmatizma u prematurnoj populaciji sa 6 godina je visoka, a od onih koji imaju astigmatizam u tom uzrastu, vi&scaron;e od dve trećine je imalo prematurnu retinopatiju. Ukupna učestalost miopije, hipermetropije i emetropije u prematurnoj populaciji sa 6 godina je 18,9%, 54,7% i 13,2%, a preostalih 13,2% su anizometropi. U vi&scaron;e od trećine dece, sa prematurnom retinopatijom u najranijem uzrastu, sa &scaron;est godina postoji gubitak vidne sposobnosti, koji je najče&scaron;će blag, no može biti i potpun.</p> / <p>The number of babies born prematurely is constantly growing, so more and more of them need appropriate systemic and ophthalmologic monitoring and treatament. Prematurity itself, represents a risk for the development of vision. This risk further reinforces the presence of retinopathy of prematurity and refractive errors. Screening and treatment of retinopathy, as well as optical correction of refractive errors provide adequate conditions for the development of vision. The aim of this study was to determine changes of biometric features of eyes of the prematurely born infants, with and without retinopathy of prematurity, during the six-year follow-up. We also want to determine the refractive status of these two groups of children in the six year, and to link changes of biometric features with their eye refraction. The study included 192 prematurely born children (384 eyes). The examinations were performed at 3 months, 12 months and 6 years and they included fundus examination and measurements of the ocular axial length, anterior chamber depth and lens thickness. After dividing the subjects into two groups, based on the results of the fundus examination at 3 months, the results of the children with and without retinopathy were compared. At the age of six we also determine the refraction of eyes, including the curvature of the cornea and corneal astigmatism, visual acuity without correction of refractive error, and then after it. Other necessary data were obtained from medical documentation. It is shown that retinopathy of prematurity affects the refractive status and visual outcome at sixth year, primarily by the changes of curvature of the cornea, the axial length of the eye and the depth of the anterior chamber, while the change in the lens thickness has no significance. Visual acuity in both eyes in the preschool age preterm born children with retinopathy of prematurity are significantly less, when compared to visual acuity in preterm infants without retinopathy, but the difference in these two values lost statistical significance after optical correction. The rate of astigmatism in preterm population of six years is high, and of those who have astigmatism in this age group, more than two-thirds had retinopathy of prematurity. The overall incidence of myopia, hypermetropia and emetropia in the prematurely born, six years old children is 18.9%, 54.7% and 13.2%, and the remaining 13.2% have anisometropia. In more than a third of children with retinopathy of prematurity at an early age, with six years, there has been loss of visual acuity, which is usually mild, but it can be complete.</p>

The work was focused on the verification of influence of quality of raw material and time-temperature conditions on the retention of nutritionally and sensory important components of the ketchups and other tomato based products. The goal of the theoretical part of this diploma thesis was the optimization of procedure of Czech tomato cultivar selection according to the highest refraction and intensive red colour. The influence of tomato ketchups production technology on retention of nutritionally significant ingredients was observed within the practical part. The samples of ketchups were sampled during different steps of production within one batch in company OTMA Sloko Mařatice. It was ketchup which was preserved by pasteurization in the glass bottle and ketchup which was preserved by hot filing to the plastic bottles. The content of lycopene, ascorbic acid, colour, viscosity, refraction and pH were measured in those samples. Furosine had been chosen as marker of thermal stress on material. The technologies can be compared on the basic of measured values from the view of retention or changes of nutritionally and sensory important components.

First part of this work is focused on the description exist methods for measuring refraction index of air. Second part deal with concrete problem realization measurement unit for monitoring of refraction index of air. Refraction index of air is measured indirect method which is based on a modified Edlen formula.

This thesis deals with the precise measurement of distances in nanometer range at ultrasonic frequencies for the purposes of vibrometry. The paper is primary focused on~nanometric displacement measurement methods. First the thesis deals with the physical phenomena based on light in the theoretical section. This includes interference of light, index of refraction, polarization, interferometry and more. Understanding of these physical laws is crucial for design and assembling of the interferometer. Subjects of interferometric method for precise and fast measurement of the nanometric displacement and vibration are discussed. Interferometer components such as lasers, photodetectors and optical elements are described are described in the final part of this section. Practical section of thesis can be divided into two parts. The design and assembling issues are discussed in the first section. Many problems which I had to solve are described. Control software and implementation of the signal processing is the subject of the second part. I met with particular problems such as phase unwrapping. I solved this problem of discontinuous phase field with user written algorithm. Finally the graphical user interface was created. Using assembled interferometer and written software application I measured vibration of Langevin transducer on ultrasonic frequencies.