This thesis describes the design, construction and testing of a new interferometer for the absolute measurement of length standards. It is assumed that this study mainly formed of three parts. Firstly, it starts with an introduction to the subject of length standards and length measurement by interferometry. The design of the new interferometer is given in detail, including the stable lasers used as light sources, fiber, optical and opto-mechanical components. In the second part of this study, the mechanical construction of the interferometer chamber is presented with temperature stabilization and controlling system. The temperature variations inside the chamber at different points in air and along the surface of the length standard are given. After that, the techniques for measurement of the refractive index of the air inside the interferometer chamber are summarized. In the last part of the thesis, a review of fringe analysis techniques is given, with an emphasis on 5 position phase-stepping algorithms. The data processing of images digitized in the interferometer is described, including the techniques developed for discontinuity removal and surface fitting. The measurement of the variation in length and flatness of the measuring faces of the length standards is described and the experimental results are given. The automated method of multiple wavelength-exact fractions is used to combine phase measurements at three wavelengths to allow accurate calculation of the length of the length standards. The experimental results are given for length standards. The uncertainty budget of whole system is calculated and presented in a table.

An important step for the design of direction finding systems is the performance evaluation using numeric electromagnetic simulation tools. In this thesis, a method is presented for both modeling and simulation in a numeric electromagnetic simulation tool FEKO. The method relies on the data generated by FEKO. The data is then processed by correlative interferometer algorithm. This process is implemented in a MATLAB environment. Different types of antenna arrays including dipole, monopole and discone antennas are used. The antenna arrays are mounted on a UAV and SUV in order to see the platform effects. The direction finding performance is evaluated for different scenarios. It is shown that the presented approach is an effective tool for understanding the direction finding characteristic of antenna arrays.

Nowadays, the increasing concern for environmental analysis and food quality control, as well as medical needs such as fast diagnosis in case of emergency events, leads to a growing need for new generations of chemical and biological sensors. These devices should have high sensitivity and reliability, perform specific detection of molecules and enable multiple parallel sensing, while being cheap, portable, fast and easy to use. Thus, a general trend tends towards bio-chemical sensors which are on-chip integrated, label-free, and compatible with standard micro-technologies. Photonic dielectric devices based on porous silicon and metallic nanostructures based on plasmon resonances are good candidates to fulfill the above requirements. Porous silicon is a biocompatible material, with a huge specific surface providing a sensitivity enhancement by several orders of magnitude compared to bulk materials; furthermore, its refractive index and thickness can be easily tuned, enabling for the realization of a large variety of photonic designs. Metallic nanostructures provide high confinement and strong field enhancement in sub-wavelength regions, leading to high sensitivities; combined with fluorescence or other sensing mechanisms such as Raman or IR spectroscopy, they have already demonstrated increased sensing potential. The realization of a hybrid device combining both elements would be highly interesting, since it could yield the advantages of both elements, and the photonic structure could shape the plasmonic resonance to develop ultrasensitive devices with narrow resonance linewidth and increased sensing depth. In this context, we realized and studied a novel hybrid photonic / plasmonic device exploiting the coupling between the surface plasmon resonance of a bowtie nano - antenna (NAs) array and the photonic modes of porous silicon (PSi) interferometer. We designed and fabricated a NAs array with resonance wavelength ~ 1.3μm on a homogeneous PSi interferometer. A thin spacing silica layer with controllable density protects the pores of PSi layer and provides a smooth surface for the fabrication of NAs. The coupling mechanisms of two elements - NA array and interferometer, are studied with 2 models, which are interferometer approach and resonator approach. The interferometer approach is focused on studying the influence of NAs array as a homogeneous layer on the fringes shift of the interferometer. For resonator approach, the coupled mode theory is applied. With these models, strong coupling between both elements are discovered: splitting. In the case of viii smaller environment variation, the hybrid device gains 5-10 fold sensitivity enhancement vs. 2 elements alone. The controllable SiO2 layer allows us to sense the index variation within PSi interferometer. This opens a route towards double parallel sensing. The development of the theoretical models under different environment is ongoing, which is expected to utilize the strong coupling for the sensing. A further investigation of the sensing potential of the hybrid device would be expected. And the 2 elements constituting the hybrid structure - the interferometer and the NA array - could be modified in order to enlarge the study to a wider family of devices with greater properties and performances. This work was performed within the framework of the program "Groups of Five Ecoles Centrales" between China Scholarship Council (CSC) and Lyon Institute of Nanotechnologies (INL, CNRS UMR 5270). The project has been supported by the Nanolyon technology platform at INL.

Multimode devices play an increasingly important role in both communication and sensing systems. Mode division multiplexing (MDM) in multimode fiber (MMF) is becoming a promising method to further increase the capacity of optical transmission link with a controllable mode coupler. Similarly, optic sensors based on core-cladding-mode interference can be widely used in measurement of refractive index (RI), temperature and strain. Fiber Bragg gratings (FBGs) in single mode operation have been extensively studied as in-line optical components for both communication and sensing applications. In recent years, research has been extended to FBGs in few-mode operation as mode couplers in MDM applications. Experimentally, mode conversion from fundamental linear polarization (LP) mode LP01 to higher order LP11 mode in two-mode FBG (TMFBG) has been observed. Index asymmetry and electric field distortion induced by ultraviolet (UV) side illumination in fabrication of FBG make the two modes no longer orthogonal. However, its spectrum analysis mainly depends on experimental data and software simulation using the complex finite element method (FEM). Here a simpler theoretical model based on coupled mode theory (CMT) and Runge-Kutta method (RKM) is proposed. An analytical expression of the mode coupling coefficient is derived and the modeling results match very well with experimental data. Abrupt fiber tapers allow power transfer between core and cladding modes and show promise as RI sensing components when two abrupt tapers are cascaded into an in-line Mach-Zehnder interferometer (MZI). The main advantage of the MZI taper sensor is its low manufacturing cost. However, the optical spectrum analyzer (OSA) used as the receiver and demodulation device in the conventional setup is still expensive. Three simplified schemes of fiber taper MZI RI sensor systems are designed and demonstrated experimentally. The transmitter and the demodulation devices for the three schemes are a single wavelength laser and a photodetector (PD), two modulated lasers and a PD together with data acquisition and processing module, and a broadband source (BBS) and a PD together with matched MZI, respectively. In all those implementations OSA is not required, which significantly lowers the cost and leads to easy integration. Although extra modulation/demodulation devices are required, the second implementation has the best performance. Automatic operation is realized by LabVIEW programming. High sensitivity (2371 mV/RI unit (RIU)) and high stability are achieved experimentally. Those new schemes have great potential to be applied to other interferometric optic sensor systems. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2014-05-09 11:44:44.837

This thesis summarizes my work at the University of Victoria to design and evaluate a proof-of-concept instrument called the Confocal Acoustic Holography Microscope (CAHM). The instrument will be able to measure small changes in temperature and composition in a fluid specimen, which can be indirectly measured via small fluctuations in the speed of sound. The CAHM combines concepts of confocal microscopy, interferometry, and ultrasonic imaging. This recent work in confocal acoustic holography has progressed from our previous research in confocal laser holography. The prototype CAHM design uses a frequency of 2.25 MHz, and can measure sound speed changes of 16 m/s, temperature changes of 5°C, with a spatial resolution of 660 μm. With future improvements to the CAHM, utilizing the latest technologies such as 2D array detectors, MEMS, and acoustic lenses, we expect resolutions of 1 m/s, 0.5°C, and 150 μm. The design of the CAHM involved the production of a 3D CAD layout of the optomechanical components and ray tracing simulations using Zemax optical design software. Simulated acoustic holograms and fringe shifts were produced and they were found to match up very well with theoretical calculations. A simplified acoustic holography instrument was built and tested. Speed of sound measurements were made for several test specimens, while keeping temperature constant. Specimens of ethanol, isopropanol, acetic acid, glycerine, and mineral oil were measured. Holograms were collected for acetic acid and mineral oil and were compared to the reference case (distilled water). The fringe spacing and phase shifts measured experimentally matched up well with the Zemax simulations and the theoretical calculations. Hence, the popular Zemax optical software can be effectively used to design acoustic instruments. To our knowledge, this is the first use of Zemax for acoustic designs. Based on the successful results of the simulations and experiments, the CAHM is expected to have many useful applications, especially in medical diagnostics where it could be used to measure density and temperature within the human body. Phase contrast images could also be used to help identify suspicious lesions, such as those found in prostate or breast tissue. Other applications include non-destructive testing of electronic and mechanical parts, measurements of fluid samples, material science experiments, and microgravity experiments, where non-invasive examination is required.

The main objective of this research is to fabricate and characterize an optically integrated interferometric sensor on standard silicon and silicon CMOS circuitry. An optical sensor system of this nature would provide the high sensitivity and immunity to electromagnetic interference found in interferometric based sensors in a lightweight, compact package capable of being deployed in a multitude of situations inappropriate for standard sensor configurations. There are several challenges involved in implementing this system. These include the development of a suitable optical emitter for the sensor system, the interface between the various optically embedded components, and the compatibility of the Si CMOS with heterogeneous integration techniques. The research reported outlines a process for integrating an integrated sensor on Si CMOS circuitry using CMOS compatible materials, integration techniques, and emitter components.

Neste trabalho apresentamos uma investigação sobre o ensino de física quântica na formação inicial de professores. Essa pesquisa foi desenvolvida junto a uma disciplina da sétima etapa do curso de Licenciatura em Física da Universidade Federal do Rio Grande do Sul, durante o segundo semestre de 2007, através de uma atividade de ensino centrada na exploração de um software que simula o interferômetro de Mach-Zehnder. Inspirados nos trabalhos de Müller e Wiesner (2002) e Pessoa Jr. (2005), utilizamos o conceito de dualidade onda-partícula como o eixo central das discussões em sala de aula. O objetivo desse estudo consiste em analisar as tensões nos enunciados de estudantes, à luz do referencial sociocultural, e avaliar em que medida os enunciados dos estudantes se articulam à internalização de conceitos de física quântica no uso de instrumentos semióticos. Os resultados mostraram que as ações mediadas pelo uso do interferômetro virtual de Mach-Zehnder, como ferramenta cultural, auxiliaram os processos de compreensão, por parte dos alunos, viabilizando a negociação de significados em sala de aula que são aceitos e compartilhados pela comunidade científica. / In this paper, we present a research of quantum physics teaching in the context of a teachers preparation course. This investigation has been developed in a seventh level discipline of a Bachelor Degree Course in Physics Education, in the Federal University of Rio Grande do Sul, during the second semester of 2006, through a didatical activity based on the use of a computer program that simulate the Mach-Zehnder interferometer. Ispired by Müller and Wiesner (2002) and Pessoa Jr. (2005), we used the concept of wave-particle duality as the central espect of discussions in the classroom. The aim of the present study was to analyze the student’s utterences, in the light of sociocultural theories, and to investigate how the speech of the studants articulates it self to the internalization of quantum physics concepts, in the use of semiotics instruments. The results showed that the actions mediated by the use of virtual Mach-Zehnder interferometer, as a cultural tool, supported the comprehendig process in studants, feasing the negotiation of meanings that are accepted and shared in scientific community.

Orientador: Keizo Yukimitu / Resumo: Vidros a base de óxidos de metais pesados (TeO2, WO3, Bi2O3) apresentam alto índice de refração, altos valores de não-linearidade óptica e alta constante dielétrica. Essas propriedades físicas possibilitam diversas aplicações, como, por exemplo, para comutação ultrarrápida em dispositivos ópticos e, exibem, quando dopados com terras raras, importantes propriedades de luminescência [1]. Vidros dos sistemas ternários xTeO2 – yB2O3 – zWO3 e xTeO2 – yB2O3 – kBi2O3 foram preparados pelo método “melt-quenching” com x de 70 a 45%mol, y de 40 a 10%mol, z de 30 a 15%mol e k com variação de 20 a 10%mol. Introduzimos o óxido de Boro para dar maior viscosidade ao material e aumentar a estabilidade térmica. Foram obtidas amostras homogêneas e transparentes para as seguintes composições: 70TeO2–10B2O3–20WO3, 70TeO2–20B2O3–10Bi2O3 e 55TeO2 –30B2O3–15Bi2O3. Dados de espectroscopia de IR revelaram que a rede dos vidros consiste basicamente das seguintes unidades estruturais: [TeO4], [WO4], [WO6], [BO4], [BO3] e Te-O-W para o sistema TeO2 – B2O3 – WO3 e de [TeO4], [BiO3], [BiO6], [BO4], [BO3] para o sistema TeO2 – B2O3 – Bi2O3. Medidas de absorção óptica das amostras foram realizadas antes e após a exposição a irradiação gama em doses de 10Gy, 1kGy, 10kGy e 50kGy e forneceram valores das bordas de absorção no intervalo de 378 a 449 nm. Obtiveram-se índices de refração da ordem de n > 2 em 633 nm através do equipamento Interferômetro de Michelson e método do ângulo de Brewster. As energias do g... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Glasses based on heavy metal oxides (TeO2, WO3, Bi2O3) have high refractive index, high values of optical nonlinearity and high dielectric constant. These physical properties enable a variety of applications, such as for ultrafast switching in optical devices and, when doped with rare earths, exhibit important luminescence [1]. Glasses in the ternary systems xTeO2–yB2O3–zWO3 and xTeO2–yB2O3–kBi2O3 were prepared from melt quenching method with x from 70 to 45 mol%, y from 40 to 10 mol%, z from 30 to 15 mol% and k with variation from 20 to 10 mol%. We introduce the Boron oxide to give a higher viscosity to the material, ie, higher thermal stability. Homogeneous and transparent samples were obtained for the following compositions: 70TeO2–10B2O3–20WO3, 70TeO2–20B2O3–10Bi2O3 and 55TeO2 –30B2O3–15Bi2O3. FTIR spectroscopy data revealed that the glass basically consists of the following structural units: [TeO4], [WO4], [WO6], [BO4], [BO3] and Te-O-W to the system TeO2–B2O3–WO3 and [TeO4], [BiO3], [BiO6], [BO4], [BO3] to the system TeO2–B2O3–Bi2O3. Optical absorption measurements of the samples were performed before and after exposure to gamma irradiation at doses of 10Gy, 1kGy, 10kGy and 50kGy and provided absorption edge values in the range of 378 to 449 nm. Were obtained refractive index of the order of n> 2 at 633 nm through the equipment Michelson´s Interferometer and Brewster's angle method. The optical gap energies obtained from these glasses are of the order of ≈ 2 to 3 eV. / Doutor

Este trabalho abordará uma breve descrição de fenômenos óticos não lineares, apresentando resultados de caracterização ótica não linear para diferentes materiais, assim como resultados para uma nova técnica de caracterização. Serão apresentados aspectos básicos de determinação do índice de refração não linear através da técnica de varredura Z que é um método bem estabelecido e amplamente difundido. Esta técnica porém não é eficiente para filmes finos e amostras com baixa não linearidade. Com a utilização de uma montagem interferométrica é possível gerar um crescimento na sensibilidade da técnica, atenuando o oscilador local sem nenhuma perda no sinal não linear gerado, acarretando em uma melhoria da relação sinal-ruído. / An introduction to nonlinear optics will be addressed in this work, presenting results of optical characterization to many different materials as well as results from a new characterization technique. Basic aspects to nonlinear index refraction measurement will be presented through Z-scan, which is a well-established method. This technique is not efficient for thin films or samples presenting low nonlinearity. Using a interferometric setup is possible to produce an increase in sensibility, attenuanting local oscillator without degrading the generated nonlinear signal, what establishes a better signal-noise relation.

Neste trabalho apresentamos uma investigação sobre o ensino de física quântica na formação inicial de professores. Essa pesquisa foi desenvolvida junto a uma disciplina da sétima etapa do curso de Licenciatura em Física da Universidade Federal do Rio Grande do Sul, durante o segundo semestre de 2007, através de uma atividade de ensino centrada na exploração de um software que simula o interferômetro de Mach-Zehnder. Inspirados nos trabalhos de Müller e Wiesner (2002) e Pessoa Jr. (2005), utilizamos o conceito de dualidade onda-partícula como o eixo central das discussões em sala de aula. O objetivo desse estudo consiste em analisar as tensões nos enunciados de estudantes, à luz do referencial sociocultural, e avaliar em que medida os enunciados dos estudantes se articulam à internalização de conceitos de física quântica no uso de instrumentos semióticos. Os resultados mostraram que as ações mediadas pelo uso do interferômetro virtual de Mach-Zehnder, como ferramenta cultural, auxiliaram os processos de compreensão, por parte dos alunos, viabilizando a negociação de significados em sala de aula que são aceitos e compartilhados pela comunidade científica. / In this paper, we present a research of quantum physics teaching in the context of a teachers preparation course. This investigation has been developed in a seventh level discipline of a Bachelor Degree Course in Physics Education, in the Federal University of Rio Grande do Sul, during the second semester of 2006, through a didatical activity based on the use of a computer program that simulate the Mach-Zehnder interferometer. Ispired by Müller and Wiesner (2002) and Pessoa Jr. (2005), we used the concept of wave-particle duality as the central espect of discussions in the classroom. The aim of the present study was to analyze the student’s utterences, in the light of sociocultural theories, and to investigate how the speech of the studants articulates it self to the internalization of quantum physics concepts, in the use of semiotics instruments. The results showed that the actions mediated by the use of virtual Mach-Zehnder interferometer, as a cultural tool, supported the comprehendig process in studants, feasing the negotiation of meanings that are accepted and shared in scientific community.