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Application of laser tracker technology for measuring optical surfacesZobrist, Tom L. January 2009 (has links)
The pages of this dissertation detail the development of an advanced metrology instrument for measuring large optical surfaces. The system is designed to accurately guide the fabrication of the Giant Magellan Telescope and future telescopes through loose-abrasive grinding. The instrument couples a commercial laser tracker with an advanced calibration technique and a set of external references to mitigate a number of error sources. The system is also required to work as a verification test for the GMT principal optical interferometric test of the polished mirror segment to corroborate the measurements in several low-order aberrations. A set of system performance goals were developed to ensure that the system will achieve these purposes. The design, analysis, calibration results, and measurement performance of the Laser Tracker Plus system are presented in this dissertation.
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Ultrafast nonlinear optics of wide-gap II-VI quantum wells and polymeric materialsBakarezos, Efthimios January 2000 (has links)
No description available.
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Development of electronic materials for infra-red detector systemsMcChesney, John-James Stuart Duncan January 1999 (has links)
Indium antimonide (InSb) and gallium antimonide (GaSb) are technologically important III-V semiconductor materials used in infrared detector systems. Yet, the application of these materials is to a certain extent limited, in that the techniques currently used for their growth are both expensive and problematic. Semiconductor electrochemical deposition, which has been successfully applied to the generation of II-VI semiconductor materials, may offer the prospect of overcoming such limitations. This work presents results that represent a significant contribution to the development of electrochemical methods for both InSb and GaSb thin film growth. The direct electrochemical co-deposition of InSb was achieved via the potentiostatic electrolysis of aqueous halide/citric acid electrolyte solutions, and for the first time, non-aqueous (ethylene glycol) electrolyte solutions containing the halides and tetraethylammonium chloride. This choice of solvents allowed the compound's deposition to be studied over a wide range of temperatures (RT to 185 °C). A first report was also made of the direct potentiostatic co-deposition of GaSb from an aqueous solution containing Ga[2](SO[4])[3] and SbCl[3].An extensive study was carried out on the relationship between the technique's fundamental growth parameters (temperature, deposition potential, solution composition etc.) and the film's compositional, crystallographic and morphological properties. The material's characterisation showed that there was tendency for the films to be non-stoichiometric. X-Ray diffraction patterns obtained from InSb films deposited from aqueous electrolyte solutions showed them to generally consist of two phases, the compound and, depending mostly on deposition potential, one of the elements. Films containing three phases, the compound and both elements, were deposited on Ti substrates from aqueous solutions and on to ITO substrates from non-aqueous solutions. These results were interpreted from both thermodynamic and kinetic viewpoints. This led to the conclusion that kinetic barriers to the formation of InSb still existed, even at the highest temperature used (~185 °C). In respect of GaSb, the compound's formation was complicated by a side reaction involving the evolution of H[2].New studies involving Scanning Electron Microscopy of the electrodeposited materials showed that they exhibited a nodular morphology, which can be explained in terms of the film's limiting current growth conditions. Energy Dispersive X-Ray Analysis (EDX) and Glow Discharge Optical Emission Spectroscopy (GDOES) identified indium chloride as a major impurity in the InSb films, especially those deposited from non-aqueous solutions. A mechanism for the incorporation of indium chloride was proposed, based on the physical entrapment of a precipitate of the compound.
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Caracterização de tecidos biológicos através de tomografia por coerência ópticaFREITAS, ANDERSON Z. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:53:15Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:58:23Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Caracterização de tecidos biológicos através de tomografia por coerência ópticaFREITAS, ANDERSON Z. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:53:15Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:58:23Z (GMT). No. of bitstreams: 0 / Neste trabalho implementamos dois sistemas de OCT, um deles utilizando fibras ópticas e um estágio de translação linear como sistema de deslocamento e foi desenvolvido no departamento de Física da Universidade Federal de Pernambuco. O outro sistema de OCT foi baseado um interferômetro de Michelson convencional, foi implementado no Centro de Lasers e Aplicações no Ipen utilizando a técnica de introdução de atraso com grade de difração e galvanômetro (fast Fourier Scanning), como sistema de varredura longitudinal. Foi implementado e um programa computacional para aquisição de dados automática, com geração das imagens de OCT em \"tempo real\". Com os sistemas desenvolvidos, foi possível detectar objetos imersos em meios espalhadores, detectar lesões de cáries induzidas in vitro quimicamente ou microbiologicamente, sendo este último um resultado original, além de avaliar a qualidade de restaurações dentárias. É importante destacar ainda que as alterações nas propriedades ópticas dos tecidos cariados podem ser detectadas pelo método de OCT muito antes de se tornarem aparentes aos métodos convencionais de detecção. Ela pode extrair informações quantitativas sobre a birrefringência do tecido, quando a técnica for sensível à polarização. Demonstramos que a análise de Fourier aplicada ao sinal de OCT permite detectar deslocamentos em sistemas periódicos e quase periódicos, abaixo do limite de resolução espacial definido pelo comprimento de coerência da fonte óptica. Com o auxílio desta metodologia aqui desenvolvida, mostramos que nosso sistema, com resolução de 10 ?m, é capaz de detectar variações em redes periódicas de algumas centenas de nanômetros entre as estruturas espalhadoras. Este desenvolvimento é uma contribuição inédita às aplicações de OCT. / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Transient electric birefringence of macromolecular systemsRudd, P. J. January 1974 (has links)
The transient electric birefringence method, i. e. the transient Kerr effect, has been employed to study the optical, electrical and geometrical properties of three macromolecular systems. An apparatus is described in which the birefringence could be measured when d. c. electric field pulses (of duration 1μs to 5s and strength up to 50 KV/cm) and a. c. electric field pulses (of duration greater than 5 ms, of frequency up to 20 kHz, and strength up to 3 KV/Cm) were applied to solutions of macromolecules. Both the linear and quadratic optical systems have been employed to measure the induced birefringence. A theoretical analysis and review of the errors implicit in such measurements is given, with suggested alignment and calibration procedures. For the first time in electro-optic work, a data-logging system and computer program have been developed and employed, and enabled the automatic recording of transient responses with subsequent high speed data analysis. Measurements have been made on a polypeptide poly – β – benzyl – 1 – aspartate in two solvents. These show how the method can be used to study a rigid macromolecule. A novel investigation was made on the interaction of an anionic surfactant, sodium dodecyl sulphate, with a flexible polymer, polyvinylpyrrolidone. The large variation of Kerr constant observed with addition of surfactant indicated a great potential use of this method for studying polymer surfactant interactions. An aqueous suspension of the bacteria E. coli was also studied, but changes in turbidity and not birefringence were the origin of the observed effects. Novel practical methods of investigation, and turbidity calculations carried out with the aid of a computer enabled size parameters and electrical properties to be determined for E. coli. For the first time such results were in agreement with electro-optic light scattering measurements.
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ADDITIVE MANUFACTURING TECHNOLOGIES FOR FLEXIBLE OPTICAL AND BIOMEDICAL SYSTEMSBongjoong Kim (10716684) 28 April 2021 (has links)
<p>Advances in additive
manufacturing technologies enable the rapid, high-throughput generation of mechanically
soft microelectromechanical devices with tailored designs for many applications
spanning from optical to biomedical applications. These devices can be softly
interfaced with biological tissues and mechanically fragile systems, which
enables to open up a whole new range of applications. However, the scalable
production of these devices faces a significant challenge due to the complexity
of the microfabrication process and the intolerable thermal, chemical, and
mechanical conditions of their flexible polymeric substrates. To overcome these
limitations, I have developed a set of advanced additive manufacturing
technologies enabling (1) mechanics-driven
manufacturing of quasi-three-dimensional (quasi-3D) nanoarchitectures with
arbitrary substrate materials and structures; (2) repetitive replication of quasi-3D
nanoarchitectures for infrared (IR) bandpass filtering; (3) electrochemical
reaction-driven delamination of thin-film electronics over wafer-scale; (4)
rapid custom printing of soft poroelastic materials for biomedical
applications. </p>
<p>First, I have developed a new
mechanics-driven nanomanufacturing method enabling large-scale production of
quasi-3D plasmonic nanoarchitectures that are capable of controlling light at
nanoscale length. This method aims to eliminate the need for repetitive uses of
conventional nanolithography techniques that are time- and cost-consuming. This
approach is innovative and impactful because, unlike any of the conventional manufacturing
methods, the entire process requires no chemical, thermal, and mechanical
treatments, enabling a large extension of types of receiver substrate to nearly
arbitrary materials and structures. Pilot deterministic assembly of quasi-3D
plasmonic nanoarrays with imaging sensors yields the most important advances,
leading to improvements in a broad range of imaging systems. Comprehensive
experimental and computational studies were performed to understand the underlying
mechanism of this new manufacturing technique and thereby provide a
generalizable technical guideline to the manufacturing society. The constituent
quasi-3D nanoarchitectures achieved by this manufacturing technology can
broaden considerations further downscaled plasmonic metamaterials suggest
directions for future research.</p>
<p>Second, I have developed mechanics-driven
nanomanufacturing that provides the capability to repetitively replicate quasi-3D
plasmonic nanoarchitectures even with the presence of an extremely brittle
infrared-transparent spacer, such as SU-8, thereby manipulating IR light (e.g.,
selectively transmitting a portion of the IR spectrum while rejecting all other
wavelengths). Comprehensive experimental and computational studies were
performed to understand the underlying nanomanufacturing mechanism of quasi-3D
plasmonic nanoarchitectures. The spectral features such as the shape of the
transmission spectrum, peak transmission and full width at half maximum (FWHM),
etc. were studied to demonstrate the bandpass filtering effect of the assembled
quasi-3D plasmonic nanoarchitecture.</p>
<p>Third, I have developed an
electrochemical reaction-driven transfer printing method enabling a one-step
debonding of large-scale thin-film devices. Conventional transfer printing
methods have critical limitations associated with an efficient and intact
separation process for flexible 3D plasmonic nanoarchitectures or
bio-integrated electronics at a large scale. The one-step electrochemical
reaction-driven method provides rapid delamination of large-scale quasi-3D
plasmonic nanoarchitectures or bio-integrated electronics within a few minutes
without any physical contact, enabling transfer onto the target substrate
without any defects and damages. This manufacturing technology enables the rapid
construction of quasi-3D plasmonic nanoarchitectures and bio-integrated
electronics at a large scale, providing a new generation of numerous
state-of-art optical and electronic systems.</p>
<p>Lastly, I have developed a new
printing method enabling the direct ink writing (DIW) of multidimensional
functional materials in an arbitrary shape and size to rapidly prototype stretchable
biosensors with tailored designs to meet the requirement of adapting the
geometric nonlinearity of a specific biological site in the human body. Herein,
we report a new class of a poroelastic silicone composite that is exceptionally
soft and insensitive to mechanical strain without generating significant
hysteresis, which yields a robust integration with living tissues, thereby
enabling both a high-fidelity recording of spatiotemporal electrophysiological
activity and real-time ultrasound imaging for visual feedback. Comprehensive <i>in vitro</i>, <i>ex vivo</i>,
and <i>in vivo</i> studies provide not only to understand the
structure-property-performance relationships of the biosensor but also to
evaluate infarct features in a murine acute myocardial infarction model. These
features show a potential clinical utility in the simultaneous intraoperative
recording and imaging on the epicardial surface, which may guide a definitive
surgical treatment.</p>
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Optical Orbital Angular Momentum from 3D-printed Microstructures for Biophotonics ApplicationsReddy, Innem V.A.K. 11 1900 (has links)
This work aims to implement 3D microstructures that generate light with orbital
angular momentum towards applications in Biophotonics.
Over the past few decades, 3D printing has established itself as the most versatile
technology with effortless adaptability. Parallel to this, the concept of miniaturiza tion has seen tremendous growth irrespective of the field and has become an estab lished trend motivated by the need for compact, portable and multi-function devices.
Therefore, when these two concepts get together, i.e., 3D printing of miniaturized
objects, it could lead to an exciting path with endless opportunities. When it comes
to optics, miniaturized 3D printing offers the potential to create compact optical
micro-systems and exhibits a way to manufacture freeform µ-optics. In particular,
two-photon lithography (TPL) is a cutting edge 3D printing technology that has re cently demonstrated groundbreaking solutions for optics as it offers high resolution
with a great degree of flexibility. With a TPL 3D printer, it is possible to fabricate
complex µ-optical elements and employ them for compelling applications.
In recent years, light with orbital angular momentum (OAM), or ”twisted” light,
has captured the interests of several researchers due to its inspiring applications. Tra ditionally, to generate OAM beams, one would require bulk, table-top optics, restrict ing their applications to over-the-table setup. An alternative approach of OAM beam
generation is through µ-structures over the fiber, as they can open up new opportu nities, especially in Bioscience, and facilitate in-vivo operations. In particular, this
probe-like setup can be used for processes such as optical trapping, high-resolution
microscopy, etc. Hence, I propose the development of a novel approach with un precedented capabilities for generating OAM beams right from single-mode optical
fibers, by transforming its Gaussian-like output beam by using complex 3D printed
microstructures. In this document, I will showcase designs and results on generating
Bessel beams (both zeroth- and high-order) and high-NA converging beams (with
and without OAM) for optical trapping from the fiber. Remarkably, I achieved the
first-ever fiber-based high-order Bessel beam generation and the first-ever fiber optical
tweezers with OAM.
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Analysis and Comparison of System Performance Using Different Modulation Schemes for Long-Haul Optical Systems and Fiber-To-The-Home Passive Optical NetworksZhu, Xianming 08 1900 (has links)
<p> Analytical expressions for the propagation impairments due to various noise sources in long-haul optical systems and fiber-to-the-home passive optical networks have been obtained. Extensive comparison has been made in this thesis for systems based on different modulation formats, and the advantage of one over the other is clearly stated.</p> <p> For long-haul fiber optical communication systems with inline amplifiers, we have studied the statistical properties of various noise sources in systems based on differential phase-shift keying (DPSK) such as the linear phase noise induced by the amplifier spontaneous emission (ASE) noise, the intra-channel four-wave mixing (IFWM) and the nonlinear phase noise induced by the interplay between ASE noise and fiber Kerr nonlinearity. The error probability of the system based on DPSK is evaluated semi-analytically. In addition, the error probability of the system based on on-off keying (OOK) is calculated taking into account the effects of ASE noise, and the intra-channel nonlinearities such as IFWM and intra-channel cross-phase modulation (IXPM). Comparison of the performance of systems based on DPSK and OOK is made thereafter.</p> <p> For fiber-to-the-home passive optical networks without inline active
photonic devices, different modulation formats have been examined for the downstream and upstream data to enable full-duplex transmission. The statistical properties of Rayleigh backscattering in single-source bi-directional optical systems have been studied including the effects of the high speed external modulation signal and the laser phase noise for systems based on DPSK and OOK. The error probabilities for systems using OOK/OOK topology and DPSK/OOK topology for downstream/upstream transmission have been evaluated and
compared.</p> <p> In addition, the interplay of the amplifier spontaneous emission noise,
fiber nonlinearity and dispersion has been examined starting from the nonlinear Schrödinger equation on the receiver current fluctuation. The variance of the current noise has been evaluated analytically using the two dimensional perturbation theory.</p> / Thesis / Master of Applied Science (MASc)
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Radiation-hard optoelectronic data transfer for the CMS trackerTroska, Jan Kevin January 1999 (has links)
No description available.
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