The necessity to align a multi component null corrector that is used to test the 8.4 [m] off axis parabola segments of the primary mirror of the Giant Magellan Telescope (GMT) initiated this work. Computer Generated Holograms (CGHs) are often a component of these null correctors and their capability to have multiplefunctionality allows them not only to contribute to the measurement wavefront but also support the alignment. The CGH can also be used as an external tool to support the alignment of complex optical systems, although, for the applications shown in this work, the CGH is always a component of the optical system. In general CGHs change the shape of the illuminating wavefront that then can produce optical references. The uncertainty of position of those references not only depends on the uncertainty of position of the CGH with respect to the illuminating wavefront but also on the uncertainty on the shape of the illuminating wavefront. A complete analysis of the uncertainty on the position of the projected references therefore includes the illuminating optical system, that is typically an interferometer. This work provides the relationships needed to calculate the combined propagation of uncertainties on the projected optical references. This includes a geometrical optical description how light carries information of position and how diffraction may alter it. Any optical reference must be transferred to a mechanically tangible quantity for the alignment. The process to obtain the position of spheres relative to the CGH pattern where, the spheres are attached to the CGH, is provided and applied to the GMT null corrector. Knowing the location of the spheres relative to the CGH pattern is equivalent to know the location of the spheres with respect to the wavefront the pattern generates. This work provides various tools for the design and analysis to use CGHs for optical alignment including the statistical foundation that goes with it.

Hologramas podem ser produzidos utilizando-se técnicas tradicionais de holografia ou podem ser gerados também por computador, conhecidos como hologramas gerados por computador (HGCs). A maioria destes hologramas opera usando luz monocromática. Por outro lado, os hologramas podem também operar com luz branca. Estes elementos de luz branca são usados em diversas aplicações, como segurança, para verificar a autenticidade dos cartões de crédito e outros documentos, porque seus processos de fabricação são difíceis e caros de serem reproduzidos. Entretanto, os hologramas de luz branca convencionais operam baseados na reflexão da luz, e apresentam alguns efeitos indesejáveis, como distorções cromáticas, como o efeito rainbow. Neste trabalho foi proposto um elemento óptico difrativo de luz branca gerado por computador. O elemento é calculado baseado na técnica de halftoning e na coerência espacial parcial de uma fonte de luz branca estendida. Os elementos da fase são produzidos através de técnicas de fabricação bem estabelecidas de circuitos integrados, e as simulações óticas são apresentadas. Não há necessidade de métodos iterativos. Os resultados das reconstruções ópticas e simuladas deste elemento de luz branca são muito semelhantes e produzem imagens nítidas, não sendo observadas distorções cromáticas. O elemento de luz branca ainda não foi descrito na literatura, e algumas de suas aplicações podem ser um correlator óptico ou arte holográfica. Este trabalho foi realizado no laboratório de óptica do departamento da engenharia elétrica do EESC, e financiado por CAPES (Coordenadoria de Aperfeiçoamento de Pessoal de Nível Superior). / Holograms can be produced using traditional holography techniques or may be also generated by computer, which are known as CGHs(Computer-generated holograms). Most of these holograms operate using monochromatic light. On the other hand, holograms can also operate with white light. These white light holograms are used in several applications, such as security, to verify the autencity of credit cards end other documents, because their fabrication processes are dificult to reproduce and are expensive. However, convencional white light holograms operate based on reflection of light, and present some undesirable effects, like chromatic distortions, such as rainbow effect. In this work it was proposed a computer-generated phase optical difractive element designed to operate under white light illumination. The element is calculated based on the halftoning technique and in the partial spatial coherence of a white light extended source. Phase elements are manufactured using well-established integrated circuits fabrication techniques and optical simulations are shown. No iterative methods are necessary. Simulated and optical reconstructions results are very similar and produce good clear images, and no chromatic distortions are observed. The white light element was not yet described on literature, and some of its applications may be an optical correlator or holographic art. This work was carried at the laboratory of optics of the department of electrical engineering of the EESC, and supported by CAPES (Coordenadoria de Aperfeiçoamento dePessoal de Nível Superior).

This thesis details the design, construction and characterisation of an ultracold atoms system, developed in conjunction with a flexible optical trapping scheme which utilises a Liquid Crystal Spatial Light Modulator (LC SLM). The ultracold atoms system uses a hybrid trap formed of a quadrupole magnetic field and a focused far-detuned laser beam to form a Bose-Einstein Condensate of 2×105 87Rb atoms. Cold atoms confined in several arbitrary optical trapping geometries are created by overlaying the LC SLM trap on to the hybrid trap, where a simple feedback process using the atomic distribution as a metric is shown to be capable of compensating for optical aberrations. Two novel methods for creating flexible optical traps with the LC SLM are also detailed, the first of which is a multi-wavelength technique which allows several wavelengths of light to be smoothly shaped and applied to the atoms. The second method uses a computationally-efficient minimisation algorithm to create light patterns which are constrained in both amplitude and phase, where the extra phase constraint was shown to be crucial for controlling propagation effects of the LC SLM trapping beam.

Colloidal particles are small particles ranging in size from nanometres to micrometres suspended in a fluid. Amongst many scientific and biological applications, they have been used to model crystallisation, vitrification, and particle interactions along with the use of colloidal model systems for the study of the fundamental nature of the fluid-crystal and fluid-glass phase transitions. It has been shown that colloidal particles can be trapped and manipulated using strongly-focused light beams known as optical tweezers, and this has paved the way for research into the area of micromanipulation using optical trapping. Holographic elements can replace multiple lenses in creating large numbers of optical tweezers and this is known as holographic optical trapping (HOT). A computer generated hologram can be designed to create large structured light fields, consisting of multiple foci, to enable trapping of multiple particles in arbitrary configurations. The overall aim of this project was to design, develop and test the suitability of a simple, inexpensive optical trapping arrangement suitable for multiple optical trapping. To achieve this, a theoretically-exact expression for the wavefront of a single point source was implemented in the coding scheme, allowing for the fast creation of multiple point sources suitable for holographic optical trapping experiments. Compensation for the spherical aberration present in the focusing optics was implemented into the coding scheme. Kodalith photographic film was chosen as the holographic recording medium for its high contrast and availability. The film has proven to be a successful medium, when used to record photographically-reduced images of high-quality printouts of the computed diffraction pattern, as it was able to successfully reproduce complex light fields. It is believed that this will be the first time that this film has been implemented for optical trapping purposes. The main limitations concerning the performance of the holograms recorded on Kodalith were the phase nonuniformities caused by unevenness in the film thickness which resulted in a failure to separately resolve light traps separated by less than about 5 (Mu)m. Index matching of the film between sheets of flat glass helped to compensate for these limitations. Holographic optical trapping was successfully observed using a variety of different initial beam powers, holographic aperture settings and light field configurations. Trapping experiments on of two types of particles (PMMA and polystyrene) were successfully conducted, with as little as ~ 150 (Mu)W per trap being required for multiple polystyrene trapping. However, particles were weakly trapped and were easily dislodged at these powers, and a higher power per trap of around 1 mW is preferred. The use of a relatively low numerical aperture (NA) 50 mm SLR lens for focusing the holographic optical traps was successful, proving that optical trapping can be conducted without the use of high NA microscope-objective lenses commonly used in other set ups. Holographic trapping of colloidal particles was successfully conducted at RMIT University for the first time proving the validity of the coding scheme, the recording method and the trapping arrangement.

Hologramas podem ser produzidos utilizando-se técnicas tradicionais de holografia ou podem ser gerados também por computador, conhecidos como hologramas gerados por computador (HGCs). A maioria destes hologramas opera usando luz monocromática. Por outro lado, os hologramas podem também operar com luz branca. Estes elementos de luz branca são usados em diversas aplicações, como segurança, para verificar a autenticidade dos cartões de crédito e outros documentos, porque seus processos de fabricação são difíceis e caros de serem reproduzidos. Entretanto, os hologramas de luz branca convencionais operam baseados na reflexão da luz, e apresentam alguns efeitos indesejáveis, como distorções cromáticas, como o efeito rainbow. Neste trabalho foi proposto um elemento óptico difrativo de luz branca gerado por computador. O elemento é calculado baseado na técnica de halftoning e na coerência espacial parcial de uma fonte de luz branca estendida. Os elementos da fase são produzidos através de técnicas de fabricação bem estabelecidas de circuitos integrados, e as simulações óticas são apresentadas. Não há necessidade de métodos iterativos. Os resultados das reconstruções ópticas e simuladas deste elemento de luz branca são muito semelhantes e produzem imagens nítidas, não sendo observadas distorções cromáticas. O elemento de luz branca ainda não foi descrito na literatura, e algumas de suas aplicações podem ser um correlator óptico ou arte holográfica. Este trabalho foi realizado no laboratório de óptica do departamento da engenharia elétrica do EESC, e financiado por CAPES (Coordenadoria de Aperfeiçoamento de Pessoal de Nível Superior). / Holograms can be produced using traditional holography techniques or may be also generated by computer, which are known as CGHs(Computer-generated holograms). Most of these holograms operate using monochromatic light. On the other hand, holograms can also operate with white light. These white light holograms are used in several applications, such as security, to verify the autencity of credit cards end other documents, because their fabrication processes are dificult to reproduce and are expensive. However, convencional white light holograms operate based on reflection of light, and present some undesirable effects, like chromatic distortions, such as rainbow effect. In this work it was proposed a computer-generated phase optical difractive element designed to operate under white light illumination. The element is calculated based on the halftoning technique and in the partial spatial coherence of a white light extended source. Phase elements are manufactured using well-established integrated circuits fabrication techniques and optical simulations are shown. No iterative methods are necessary. Simulated and optical reconstructions results are very similar and produce good clear images, and no chromatic distortions are observed. The white light element was not yet described on literature, and some of its applications may be an optical correlator or holographic art. This work was carried at the laboratory of optics of the department of electrical engineering of the EESC, and supported by CAPES (Coordenadoria de Aperfeiçoamento dePessoal de Nível Superior).

No description available.

Orientador: Prof. Dr. Marcos Roberto da Rocha Gesualdi / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia Elétrica, 2016. / A holografia permite o registro e a reconstrução óptica de imagens 3D de objetos, pois um holograma carrega as informações de intensidade e fase da função da onda óptica espalhada pelo objeto. Com a evolução do armazenamento e da velocidade de processamento de dados em computadores, a viabilidade dos hologramas gerados por computador tem evoluído no decorrer dos anos. Na atualidade, a implementação experimental dos CGHs tem sido realizada por meio de novos dispositivos opto-eletrônicos, como os moduladores espaciais de luz, câmeras CMOS, e CCDs de alta resolução, além dos novos materiais fotossensíveis, permitindo o registro e reconstrução óptica de objetos tridimensionais e de feixes ópticos especiais. Por outro lado, as possibilidades do FPGA, um dispositivo lógico programável capaz de criar diferentes tipos de circuitos digitais, permite desenvolver um hardware capaz de melhorar os tempos de processamentos para a geração dos hologramas sintéticos. O objetivo deste trabalho é estudar a holografia gerada por computador a partir de algoritmos (software), a realização da reconstrução óptica destes hologramas usando dispositivos SLMs, bem como as possibilidades de implementação dos CGHs via FPGA (hardware) de cenas 3D virtuais. Desta forma, foram obtidos resultados de construção (gravação) numérica de CGHs de imagens estáticas e dinâmicas, 2D e 3D, via MATLAB e de reconstrução (reprodução) óptica usando dispositivos SLMs destas imagens estáticas e dinâmicas (cenas). / Holography allows three-dimensional recording and optical reconstruction of objects, as a hologram carries the information of the intensity and the optic wave¿s phase function spread over the object. With the evolution of data storage and processing speed in computers, the viability of creating holograms by computer has advance through the years. Today, the CGHs¿s experimental implementation has been performed by new optoelectronic devices, as special light modulators, CMOS cameras, e high resolution CCDs, besides new photosensitive materials, allowing recording and optical reconstruction of 3D objects and special optic beams. On the other hand, FPGA possibilities, a logic programmable device able to create different kind of digital circuits, enables the development of hardware to improve processing time when creating synthetic holograms. The main objective of this work is to study holography created by computer using algorithms (software), moreover the optical reconstruction of holograms utilizing SLMs devices, as the possibility of implementing CGHs by FPGA (hardware), of virtual 3D scenes. Therefore, results of numeric construction (recording) of CGHs of static and dynamic images were obtained, 2D and 3D, using MATLAB, and the optical reconstruction (reproduction) using SLMs devices of these images (scenes).

Orientador: Prof. Dr. Marcos Roberto da Rocha Gesualdi / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia Elétrica, 2017. / Estudos da aplicação de moduladores espaciais de luz do tipo LCoS (Liquid Cristal on Silicon) e técnicas holográficas em substituição às máscaras no processo de fotolitografia são apresentados. Hologramas Gerados por Computador (HGC) a partir de duas imagens com dimensões conhecidas, simulando uma máscara de campo claro e uma máscara de campo escuro, foram aplicados a um modulador espacial de luz LCoS conectado a um arranjo óptico capaz de reduzir as imagens reconstruídas, permitindo o levantamento dos parâmetros de maior relevância no processo de fotolitografia para fabricação de estruturas micrométricas e, a partir da sua caracterização, identificar os limites impostos pelo modulador espacial de luz LCoS nesse processo. Registro das imagens, com diferentes dimensões, adquiridas à partir da reconstrução dos HGC provenientes das máscaras de campo claro e campo escuro, foram realizados através de uma câmera CCD e filmes de alta resolução. Os resultados permitiram a visualização e medição de estruturas com até 13 Pm e representam uma base de estudo na busca de alternativas para substituição das máscaras em processos de fotolitografia / Application studies of the Spatial Light Modulators LCoS type (Liquid Crystal on Silicon) and holographic techniques to replace the masks in the photolithography process are presented. Computer-generated Holograms (HGC) from two images with known dimensions, simulating a clear field mask and a dark field mask, were applied to a Spatial Light Modulators LCoS connected to an optical arrangement capable of reducing the reconstructed images, allowing the survey of the parameters of greater relevance in the process of photolithography to fabricate micrometric structures and from its characterization to identify the limits imposed by the Spatial Light Modulators LCoS in this process. Recording of the images, with different dimensions, acquired from the reconstruction of the HGC from clear field and dark field masks, were performed through a CCD camera and high resolution films. The results allowed the visualization and measurement of structures up to 13 ìm and represent a base of study in the search of alternatives for replacing the masks in photolithography processes.

Neste trabalho desenvolvemos duas séries de EODs operando em regime simultâneo de modulação das componentes de fase e de amplitude de uma frente de luz (Modulação Complexa Completa MCC). A primeira destas séries foi constituída por Hologramas de Fourier calculados através do Algoritmo Iterativo da Transformada de Fourier (Iterative Fourier Transform Algorithm IFTA) e a segunda, por Hologramad de Fresnel cujo cálculo da propagação da luz foi obtido por filmagem linear espacial proveniente da solução da Equação de Helmholtz no domínio da frequência. Nos dois casos, a Modulação Complexa Completa foi implementada fisicamente empregando, para realizar a modulação de fase, um micro-relevo gravado em um filme de DLC (Diamond Like Carbon) depositado sobre um substrato de vidro. Sobre este relevo foi implementada a modulação de amplitude, através da deposição de um filme de alumínio, no qual foram realizadas micro-aberturas diferentes cujas áreas eram proporcionais à amplitude em cada pixel. Nos Hologramas de Fourier, uma diferente espessura do filme DLC localizada sobre cada pixel foi responsável pela modulação do valor de fase relativo àquele ponto. Nos Hologramas de Fresnel, a combinação de duas espessuras diferentes do filme de DLC em cada pixel foi responsável pela modulação do valor de fase relativo a cada ponto. Os elementos foram caracterizados física e opticamente e produziram imagens de reconstrução totalmente livres de ruídos do tipo speckle. Também em caráter de avaliação dos resultados foi efetuada a comparação entre as imagens de reconstrução óptica produzidas pelos Hologramas de Fresnel com MCC com as produzidas por Hologramas de Fresnel convencionais em regime de modulação de fase. / In this work, we developed two sets of DOESs able to modulate both phase and amplitude components of light simultaneously (Complete Complex Modulation CCM). The first set is composed of Fourier Holograms calculated by Iteractive Fourier Transform Algorithm (IFTA). The second set is composed by Fresnel Holograms, which light propagation was calculated by spatial linear filtering obtained from the solution of the Helmholtz Equation in the frequency domain. In both cases, Complete Complex Modulation was physically implemented by a micro-relief, for phase modulation, recorded on a Diamond Like Carbon (DLC) film deposited on a glass substrate. Amplitude modulation was implemented on a aluminum fim layer deposited on this relief. In this layer, micro-appertures proportional to the amplitude on each pixel, were recorded. Phase modulation in each pixel of the Fourier Holograms was achivied by different thicknesses of the DLC film. For Fresnel Holograms, phase modulation was achieved by combining two different thicknesses of DLC film inside each pixel. The elements were physically and optically characterized and produced reconstruction images completly free of speckle like noise. The optical reconstruction images produced from Fresnel Holograms working in CCM regime and convencional phase-only modulated Fourier Holograms were compared.

Les systèmes micro-opto-électro-mécaniques (MOEMS) représentent un atout considérable pour les technologies de demain et démontrent régulièrement leur capacité d'innovation dans tous les domaines de recherches. L'astronomie en profite déjà à travers l'optique adaptative et leur versatilité a récemment permis de développer un nouveau spectro-imageur BATMAN qui verra sa première lumière au Telescopio Nazionale Galileo (TNG) à La Palma (Iles Canaries). Le code de contrôle du MOEMS permettant l'automatisation de l'acquisition des spectres a été le point de départ de mon travail au LAM.La partie principale de ce manuscrit traite d'une seconde application imaginée en associant les MOEMS à un matériau photochromique développé à Polytecnico di Milano (Italie) qui peut prendre deux états différenciés par leur transparence. Le MOEMS, initialement utilisé pour la projection d'image, permet de moduler la dose d'énergie lumineuse projeté sur la plaque photochromique qui répond en s'éclaircissant progressivement. Ce procédé permet donc d'enregistrer des images en niveau de gris sur la plaque et notamment des hologrammes générés par ordinateur (CGH) utilisés en métrologie optique. Actuellement, les CGHs utilisés sont binaires, mais notre procédure permet d'enregistrer des CGHs quantifiés en amplitude avec une résolution de 13,68 µm et une précision inférieure à 1% en terme de transparence malgré un éclairage peu homogène. La quantification des CGHs de type Fresnel et Fourier ont été calculés, réalisés et testés avec succès. Deux nouveaux algorithmes de Fourier ont étaient imaginés, réalisés et ont montrés des performances très supérieurs au code usuel de Lee qui est un codage binaire. / Micro-opto-electro-mecanical systems (MOEMS) are primordial tools for future applications in several scientific fields as telecommunications or image display. Astronomy takes also advantage of their great adaptatbility thanks to the development of adaptative optics; a new spectro-imager called BATMAN has recently been develloped to be installed at Telescopio Nazionale Galileo (TNG) in the Canaries Islands. The control of the MOEMS allowing computerizing this processus has been the starting point of my work at the LAM.The main part of this manuscript deals with another application conceived thanks to the association of the characteristics of MOEMS and photosensitive materials developed at Politecnico di Milano (Italy). These materials can be put in two states differentiated by their transparency. The MOEMS, initially used to display images, allows controlling the dose of light projected on the photocrhomic plate which reacts by becoming more and more transparent. This process permit to record Computer Generated Holograms (CGHs) in grayscale which are used in optical metrology. Today, binary CGHs are used but our process allows to record amplitude quantified CGHs with a resolution of 13.68 µm and a precision better than 1% in term of transparency, even with a non homogeneous illumination beam. Comparative studies have shown advantages of quantified CGHs of Fresnel and Fourier families. Two new Fourier algorithms have been conceived thanks to use of the third dimension offered by the control of the transparency. They have been realized and tested succesfully, and have shown much better performances than the current binary coding, so called Lee algorithm.