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    Optical Sciences (952)
    Graduate College (950)Honors College (1)AuthorsPeyghambarian, Nasser (66)Barrett, Harrison H. (38)Sasian, Jose (36)Dereniak, Eustace L. (33)Liang, Rongguang (32)Norwood, Robert A. (32)Gmitro, Arthur F. (31)Wright, Ewan M. (31)Wyant, James C. (31)Mansuripur, Masud (27)View MoreTypestext (952)Dissertation-Reproduction (electronic) (475)Electronic Dissertation (313)Electronic Thesis (85)Thesis-Reproduction (electronic) (78)Electronic Report (1)maps (1)

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    A FIXED-DELAY, FREQUENCY-SHIFTED MICHELSON INTERFEROMETER FOR REMOTE AIR TEMPERATURE MEASUREMENT

    Johnson, Lawrence Alan, 1947- (The University of Arizona., 1981)
    The spectral width of single-frequency radiation scattered in the atmosphere may be used to determine air temperature. In general, the measurement is complicated by pressure dependent changes in the spectral profile of the scattered radiation and by the inherently low received signal levels. A fixed-delay Michelson interferometer minimizes both of these problems by: (1) exhibiting a low sensitivity to pressure induced changes in the scattered spectrum and (2) optimally utilizing the available signal. By frequency shifting the signal in one arm of the interferometer relative to the other it is possible to efficiently modulate the output of the interferometer and make it insensitive to small changes in the center frequency of the scattered spectrum. Laboratory results obtained using a fixed-delay, frequency-shifted Michelson interferometer demonstrate the ability of this instrument to remotely measure air temperatures in the range 290 K to 310 K with an uncertainty of ±2 K with averaging times on the order of seconds at a received signal level of 6 x 10⁻¹⁰ watts.
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    Acoustic Imaging of Geosynchronous Satellites via a Newly Upgraded Hyper-Temporal Imaging Instrument

    Morris, Marita D. (The University of Arizona., 2018)
    Presented here are investigations into acoustic imaging techniques designed to identify geosynchronous (GEO) satellites by their polarization signatures. In order to conduct these observations, a hyper-temporal imaging (HTI) instrument has been developed. This new instrument has been designed to operate on the 61” Kuiper telescope, located on Mount Bigelow, Arizona. At the core of HTI is a polarizing beam splitter and two identical cameras which record s and p linear polarized channels simultaneously. These two channels are then used to calculate degree of linear polarization of the signal over time. The latest upgraded cameras are each Andor Zyla 4.2+sCMOS. These cameras are capable of recording data at speeds greater than 1000fps with a Field of View of 5 arcminutes. Typical site conditions at the telescope give an estimated 1 arcsecond of seeing (on good nights), thus the optical aberrations in HTI have been designed to be far less than this limit. Observations with the HTI instrument were conducted over 10 nights and data were collected on 22 different GEO satellites plus several stars for comparison. Here three of these target satellites are analyzed in detail for their unique signatures. StarOne/Brasilsat B4 (HS-376W bus) is a known spin-stabilized satellite. It showed clear peaks in the signal of: 0.53Hz, 1.06Hz, 1.59Hz, 2.1Hz, 2.65Hz, 3.18Hz, and 3.71Hz. Ciel-2 (Spacebus-4000C4 bus) is one of the larger of these GEO satellites and showed a signal which may be consistent with a satellite maneuver. This signal showed peaks in the power spectrum of DOLP at: 0.028, 0.043, 0.08, 0.26Hz. The third satellite, DirecTV-15 (Eurostar-3000 bus) also contained a signal which appears to be a satellite maneuver taking place. Peak frequencies of 0.069Hz and ~0.05Hz were observed in this signal.
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    Ocular Distortion Measurement and Relationship with Refractive Error

    LaVilla, Edward Anthony (The University of Arizona., 2018)
    The underlying drivers of refractive error development in the human eye remain open areas of research. Axial elongation, peripheral ametropia, neurotransmitters at the retinal surface and environmental stimuli are a few factors that have been studied to describe the onset and progression of refractive error development. However, the ametropia puzzle remains unsolved and the number of people afflicted by ametropia is growing. One possible driver for refractive error development is distortion in the retinal image. However, no systems are available to objectively measure ocular distortion. To enable the measurement of ocular distortion, a novel imaging system is created and tested in a sample population. Using a modified fundus camera, a target is projected onto the retinal surface and imaged to a detector. A distortion criterion for a rotationally non-symmetric optical system is used to analyze the resulting distortion pattern. A simulated population of one thousand different configurations, for a model eye spanning -20 to +9 D, is used to investigate ocular distortion prior to human trials. A small human trial cohort was imaged using the modified fundus camera and compared to the simulated data set. The repeatability of the distortion measurements and its relationship to refractive error is investigated.
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    Study of the Impact of Nonlinearities on Advanced Modulation Formats in Optical Systems and Networks

    Wang, Yi-Ping (The University of Arizona., 2017)
    Chromatic dispersion, Kerr nonlinearity, and amplified spontaneous emission (ASE) noise are three common problems for the optical communication systems. For the systems using direct detection scheme, we detect the power of the signal. Therefore, the information is carried by the signal power, which is pulse amplitude modulation (PAM). In this system, chromatic dispersion and Kerr nonlinearity will broaden the pulse and cause intersymbol interference, while ASE noise will degrade the signal to noise ratio and increase the error rate. For the system using coherent detection, we can detect not only the power but also the phase of the signal. Thus, the information can be carried by the power and the phase of the signal, which is quadrature amplitude modulation (QAM). In this system, the signal will see a phase shift during the propagation induced by the Kerr nonlinearity, which will cause an error if the phase shift is not corrected on the receiver side. In order to optimize the performance or design the solution for the system, a careful study of the impact of these three effects on the signal is needed. In this thesis, I study the theory of the pulse broadening effect caused by chromatic dispersion and Kerr nonlinearity, and as well as the bit error rate performance with the accumulation of ASE noise. Moreover, I use split-step Fourier method to solve the nonlinear Schrödinger equation in MATLAB and simulate the propagation of 2-PAM and 4-QAM signal. The impact of these three effects and the bit error rate behavior of the coherent detection system are demonstrated and discussed.
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    Rare-earth-doped glass waveguides for amplifiers and lasers

    Ohtsuki, Tomoko, 1960- (The University of Arizona., 1996)
    Several different glass materials were investigated for waveguide amplifier and laser applications, and the potential to realize practical devices with these materials were examined using waveguides fabricated by ion exchange processes. Channel waveguides in an erbium doped phosphate laser glass were fabricated by a dry silver-film ion exchange technique, and the effects of high Er³⁺ concentration were investigated in terms of Er³⁺ ion interactions and energy transfer from Yb³⁺ to Er³⁺. Cooperative upconversion coefficients of the ⁴I₁₃/₂ level,7.7±0.7x 10⁻¹⁹ cm³/sec and 9.3±0.7x10⁻¹⁹ cm³/sec, were obtained experimentally for Er³⁺ concentration of 1x10²⁰ cm³ in the bulk and waveguide samples, respectively. These values are one order of magnitude smaller than the ones reported for silica glass. The increase in the cooperative upconversion coefficient with the increase in Er³⁺ concentration was found to be small. The effects of cooperative upconversion on the gain performance were analyzed for different Er³⁺ concentrations using a theoretical model which adopted experimentally obtained parameters. Given the small cooperative upconversion coefficients in this glass, Er³⁺ concentrations potentially as high as 3.7x10²⁰ cm⁻³ were shown to be feasible by the modeling. This would result in a 12 dB gain with a 4 cm long waveguide for 150 mW pump power at 1.48 μm. The transfer efficiency from Yb3+ to Er³⁺ was found to be 95% or higher for samples with Er³⁺ concentrations of 1.9x10²⁰ cm⁻³, and 24x10²⁰ cm⁻³, even when the ratio of the concentrations, Yb/Er, is only about 1.2 and 2. Planar channel waveguides of rare-earth doped fluoride glass were demonstrated with single mode excitation and propagation loss below 3 dB/cm. The waveguide core was fabricated by Ag⁺-Na⁺ molten salt ion exchange process in a borosilicate glass (BGG31), and a Nd³⁺-doped ZBLAN glass was used as a cladding. A 0.45 dB signal amplification at 1.064 μm was observed in the fabricated 1cm long waveguide, and a 0.9 dB amplification is expected at the emission peak (1.049 μm). Modeling results suggest that 2.5 dB/cm is possible by improving surface flatness of the ZBLAN glass.
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    An optical probe of thin film and surface contamination based on surface plasmon resonance.

    Wang, Ran-Hong Raymond. (The University of Arizona., 1990)
    The microcontamination of optical surfaces or optical thin films affects many of their properties. In this work, we investigated several measurement systems to detect many types of surface contamination of coatings based on the surface plasmon resonance (SPR) phenomenon. The attenuated total reflection (ATR) coupling, also known as the Kretschmann configuration, excited the nonradiative surface plasmon wave for SPR measurement. Several microcontamination layers thinner than 10 nm were studied. The results showed that in all the cases SPR curves shifted to larger incident angles. From the amount of angle shift, the thickness of contamination was determined with a sensitivity of as little as one angstrom. The optical constants of those contamination layers were also derived. The shifts of the SPR curves served as an index for the efficiency of cleaning processes. It was found that the contamination by moisture can be removed with Iso-propyl alcohol by the ultrasonic cleaning process, while acetone was the more effective solvent in removing the contamination left by strippable coating residue show that the contamination layer was roughened by ultrasonic cleaning. In studies of island-like discontinuous thin layers of Ag, Al, and MgF₂, we found that the refractive index of MgF₂, a dielectric film material, slightly decreased as the thickness decreased, but for discontinuous metal films, the optical constants changed rapidly and became more dielectric in nature. Direct detection of contamination by coating processes in a small vacuum chamber was also carried out. In a chamber with high backstreaming from a diffusion pump, a broad SPR curve for an Ag film revealed obvious optical constant changes. Measuring and comparing the shift indicates that a significant amount of contamination was occurring right after the coating was completed. This suggests that for good evaporated optical thin films, it is important to have a more tightly controlled evaporation process. Finally, particulate, as well as layered, contamination can also be measured. A radiative SPR wave was generated by illuminating a contaminated surface. Similar radiative SPR waves also can be observed by adding a rough contaminant layer on an Ag film.
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    From Cell to Barbule the Optics of Iridescent Bird Feathers

    Piatt, Georgia (The University of Arizona., 2018)
    There are brightly colored birds spanning the globe. These fabulous animals get their colors from a variety of different sources. Some birds use pigments while others have specialized shapes and forms creating optical phenomena such as thin-films, and photonic crystals among others; within the cells of their feathers to reflect and refract light to create vibrant colors. The spectacular Bird-of-paradises’ feathers are just as incredible as the birds themselves. The male Parotia wahnesi Bird-of-paradise puts on an elaborate show to attract a mate, part of this show is flashing an iridescent ornament from under his chin called a breast ornament. To the female sitting on the branch above the male, it is a brilliant yellow, but when the ornament is flush against the bird, it reflects a variety of colors from purple to green. The colors from the ornament feather, can be modeled as a structured thin film using non-sequential optics software. The models tested were created from a digitized shape of a cell and barbule of the ornament feather. There is a combination of .05µm of melanin with a refractive index of n = 2+.01i and .128µm of keratin with a refractive index of n=1.5 in 31 alternating layers overlaid on the topography of the bottom of the barbule. The outer shell of the cell is created by a single 21µm layer of keratin. Together this created a vivid color pattern which closely matches measurements and observation in the real world. In contrast to the vivid Whanes’s Parotia, the white tip of a Mourning Dove flight feather is also examined. The feather, composed of keratin and air, lacking any organization as well as any recognizable outer structure.
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    Software Implementation of a Combined Fluorescence and Swept Source Optical Coherence Tomography Imaging System

    Sassu, Matthew George (The University of Arizona., 2018)
    This paper serves as a detailed overview of the software developed for the Falloposcope endoscope being developed by the Jennifer Barton Optics Tissue Laboratory. The Falloposcope is designed for a screening procedure for early detection of ovarian cancer in the fallopian tubes. The software controls a charge-coupled device (CCD) camera to perform reflectance and fluorescence imaging, which serves to navigate the endoscope to the fallopian tubes and surveil suspicious tissue regions. It also controls a swept source optical coherence tomography (SS-OCT) imaging system to provide high resolution, cross-sectional tomographic images of these tissue regions. CCD imaging is performed using a Princeton Instruments Pixis 1024B Digital CCD camera system. OCT imaging is performed using a Santec HSL-2100 swept source infrared laser and BPD-200-ST photodetector, as well as an AlazarTech ATS-9462 data acquisition board. Data from these instruments is displayed on a graphic user interface written in C++/CLI. This paper details how each of these imaging systems functions, from hardware control through data processing and visualization, as well as how more challenging programming tasks were completed. The core functionality of each system is complete, but there remain some parameters of the OCT data display which remain to be finalized. The available options, as well as the standard practices within the medical industry around OCT imaging, are discussed.
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    Single-Chip LiDAR by Multi-Order and Multi-Pulse Beam Steering with Digital Micro Mirror Device

    Rodriguez, Joshua Miguel (The University of Arizona., 2019)
    We demonstrate the feasibility of enhancing the scanning rate for MEMS and diffraction based beam steering employing Digital Micromirror Device (DMD) by one to two orders of magnitude, which is configured as a programmable blazed grating. The tilt movement of micromirrors synchronizes with multiple pulses from multiple laser sources that sequen- tially redirect the pulses to multiple diffraction orders within μs. The approach opens up a pathway to achieve a LIDAR system with a scanning rate over 1M samples/s while leveraging a state of the art DMD and a moderate number of laser sources.
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    Quantum Well Intermixing For Photonic Integrated Circuits

    Sun, Xiaolan (The University of Arizona., 2007)
    In this thesis, several aspects of GaAsSb/AlSb multiple quantum well (MQW) heterostructures have been studied. First, it was shown that the GaAsSb MQWs with a direct band gap near 1.5 μm at room temperature could be monolithically integrated with AlGaSb/AlSb or AlGaAsSb/AlAsSb Bragg mirrors, which can be applied to Vertical Cavity Surface Emitting Lasers (VCSELs). Secondly, an enhanced photoluminescence from GaAsSb MQWs was reported. The photoluminescence strength increased dramatically with arsenic fraction as conjectured. The peak photoluminescence from GaAs(0.31)Sb(0.69) was 208 times larger than that from GaSb. Thirdly, the strong photoluminescence from GaAsSb MQWs and the direct nature of the band gap near 1.5 μm at room temperature make the material favorable for intermixing studies. The samples were treated with ion implantation followed by rapid thermal annealing (RTA). A band gap blueshift as large as 198 nm was achieved with a modest ion dose and moderate annealing temperature. Photoluminescence strength for implanted samples generally increased with the annealing temperature. The energy blueshift was attributed to the interdiffusion of both the group III and group V sublattices. Finally, based on the interesting properties of GaAsSb MQWs, including the direct band gap near 1.5 μm, strong photoluminescence, a wide range of wavelength (1300 – 1500 nm) due to ion implantation-induced quantum well intermixing (QWI), and subpicosecond spin relaxation reported by Hall et al, we proposed to explore the possibilities for ultra-fast optical switching by investigating spin dynamics in semiconductor optical amplifiers (SOAs) containing InGaAs and GaSb MQWs. For circularly polarized pump and probe waves, the numerical simulation on the modal indices showed that the difference between the effective refractive index of the TE and TM modes was quite large, on the order of 0.03, resulting in a significant phase mismatch in a traveling length larger than 28 μm. Thus the FWM conversion efficiency was exceedingly small and the FWM mechanism in SOAs used for investigation of all-optical polarization switching was strongly limited.
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