Optics Commons^™

Infrared And Electro-Optical Stereo Vision For Automated Aerial Refueling, William E. Dallmann

Theses and Dissertations

Currently, Unmanned Aerial Vehicles are unsafe to refuel in-flight due to the communication latency between the UAVs ground operator and the UAV. Providing UAVs with an in-flight refueling capability would improve their functionality by extending their flight duration and increasing their flight payload. Our solution to this problem is Automated Aerial Refueling (AAR) using stereo vision from stereo electro-optical and infrared cameras on a refueling tanker. To simulate a refueling scenario, we use ground vehicles to simulate a pseudo tanker and pseudo receiver UAV. Imagery of the receiver is collected by the cameras on the tanker and processed by a …

Design And Optimization Of A 3-D Plasmonic Huygens Metasurface For Highly-Efficient Flat Optics, Bryan M. Adomanis

Theses and Dissertations

For miniaturization of future USAF unmanned aerial and space systems to become feasible, accompanying sensor components of these systems must also be reduced in size, weight and power (SWaP). Metasurfaces can act as planar equivalents to bulk optics, and thus possess a high potential to meet these low-SWaP requirements. However, functional efficiencies of plasmonic metasurface architectures have been too low for practical application in the infrared (IR) regime. Huygens-like forward-scattering inclusions may provide a solution to this deficiency, but there is no academic consensus on an optimal plasmonic architecture for obtaining efficient phase control at high frequencies. This dissertation asks …

Reconstruction Of The 3d Temperature And Species Concentration Spatial Distribution Of A Jet Engine Exhaust Plume Using An Infrared Fourier Transform Spectrometer Hyperspectral Imager, Mason D. Paulec

Theses and Dissertations

The measurement of combustion byproducts is useful for determining pollution of any fuel burning application, efficiency of combustion, and determining detectability of aircraft exhausts. Both intrusive and non-intrusive techniques have been utilized to measure these quantities. For the majority of the non-intrusive techniques, the absorption and emission spectra of the gases are utilized for measurements. For this research, the use of the Telops Infrared Fourier Transform Spectrometer (IFTS) Hyperspectral Imager (HSI) was explored within the scope of combustion diagnostic methods, as an option for remote measurements of a jet turbine to determine concentration of species and temperature of the combustion …

Techniques For Improved Space Object Detection Performance From Ground-Based Telescope Systems Using Long And Short Exposure Images, David J. Becker

Theses and Dissertations

Space object detection is of great importance in the highly dependent yet competitive and congested space domain. Detection algorithms employed play a crucial role in fulfilling the detection component in the space situational awareness mission to detect, track, characterize and catalog unknown space objects. Many current space detection algorithms use a matched filter or a spatial correlator on long exposure data to make a detection decision at a single pixel point of a spatial image based on the assumption that the data follows a Gaussian distribution. This research focuses on improving current space object detection algorithms and developing new algorithms …

Automating Mobile Device File Format Analysis, Richard A. Dill

Theses and Dissertations

Forensic tools assist examiners in extracting evidence from application files from mobile devices. If the file format for the file of interest is known, this process is straightforward, otherwise it requires the examiner to manually reverse engineer the data structures resident in the file. This research presents the Automated Data Structure Slayer (ADSS), which automates the process to reverse engineer unknown file for- mats of Android applications. After statically parsing and preparing an application, ADSS dynamically runs it, injecting hooks at selected methods to uncover the data structures used to store and process data before writing to media. The resultant …

Efficient Phase Retrieval For Off-Axis Point Spread Functions, Salome Esteban Carrasco

Theses and Dissertations

A novel pairing of phase retrieval tools allows for efficient estimation of pupil phase in optical systems from images of point spread functions (PSFs). The phase retrieval algorithm uses correlation of modeled phase in the focal plane to decouple aberrations that are difficult to identify in complex PSFs. The use of a phase kernel that departs from the Fresnel approximation for off-axis PSFs is a more accurate representation of wavefront phase in finite conjugate imaging. The combination of the approximation and phase correlation algorithm can be more efficient and accurate than generic algorithms.

Investigation Of Scramjet Flowfield Temperatures At The Boundary Layer With Hyperspectral Imaging, Amy M. Kerst

Theses and Dissertations

Within the domain of chemical propulsion, the fields of combustion diagnostics and computational fluid dynamics each have a long history, and both have led to a better understanding of complex phenomena yielding practical improvements in propulsion systems. As more exotic forms of propulsion are developed, the importance of -- and often the challenges with -- both diagnostic and simulation capabilities also increase. In the case of scramjet combustion, these challenges primarily arise from the highly turbulent environment in the combustion cavity, and the high-speed, compressible nature of the flowfield. Efforts are underway to develop computer models of scramjet combustion environments …

Modeling A Space-Based Quantum Link, Alexander W. Duchane

Theses and Dissertations

Quantum sources and single photon detectors have improved, allowing quantum algorithms for communication, encryption, computing, and sensing to transition from theory and small-scale laboratory experiments to field experiments. One such quantum algorithm, Quantum Key Distribution, uses optical pulses to generate shared random bit strings between two locations. These shared bit strings can be turned into encryption keys to be used as a one-time-pad or integrated with symmetric encryption techniques such as the Advanced Encryption Standard. This method of key generation and encryption is resistant to future advances in quantum computing which significantly degrade the effectiveness of current asymmetric key sharing …

Laser Heating Of Graphite And Pulsed Laser Ablation Of Titanium And Aluminum, William A. Bauer

Theses and Dissertations

Tactical missions for laser weapons include a wide variety of targets, increasing the demands on the laser lethality community. New approaches to reducing the dimensionality of laser and materials interactions are necessary to increase predictive capability. Self-contained systematic experimental study was conducted on continuous wave and pulsed laser interaction with graphite, Al, and Ti. The spectroscopy and plume dynamics from the heating and ablation of these materials was examined to characterize laser weapons effects, develop graphite response for thermal protection systems, and provide optical diagnostics for materials processing. Furthermore, analysis of ablated plume velocity distributions shows application of conventional Maxwell-Boltzmann …

The Fresnel Zone Light Field Spectral Imager, Francis D. Hallada

Theses and Dissertations

This thesis provides a computational model and the first experimental demonstration of a Fresnel zone light field spectral imaging (FZLFSI) system. This type of system couples an axial dispersion binary diffractive optic with light field (plenoptic) camera designs providing a snapshot spectral imaging capability. A computational model of the system was developed based on wave optics methods using Fresnel propagation. It was validated experimentally and provides excellent demonstration of system capabilities. The experimentally demonstrated system was able to synthetically refocus monochromatic images across greater than a 100nm bandwidth. Furthermore, the demonstrated system was modeled to have a full range of …

Cavity Perturbation Technique Of 10 Ghz Cylindrical Resonator For Modeling Rf/Ir Sensor Radomes/Windows, Marvin-Ray Arida

Theses and Dissertations

The dielectric properties of candidate materials for radomes or sensor windows on hypersonic vehicles, which can reach temperatures above 1,500° Celsius when traveling greater than Mach 5, are required. Although there has been recent scientific interest in the temperature dependence of the dielectric constant, little is known for temperatures near 1,500° Celsius and above. Current research utilizes large laboratory-sized furnaces to achieve these temperatures. This also requires large sample sizes, which are expensive; such expense is greatly multiplied when sweeping through hundreds of materials for research and development. In an effort to reduce these costs, this thesis modeled a 7.0 …

Using Principal Component Analysis To Improve Fallout Characterization, Derek W. Haws

Theses and Dissertations

Previous research conducted at Lawrence Livermore National Laboratory (LLNL) and the Air Force Institute of Technology (AFIT) has shown a correlation between actinide location and elemental composition in fallout from historic weapons testing. Fifty spherical fallout samples were collected from near ground zero of a surface burst weapons test. The samples were mounted in an aluminum puck then ground and polished to a hemisphere exposing the central plane. Physical morphologies of the samples ranged from clear to opaque with inclusions, voids, and/or uniform characteristics. Spectroscopy data were collected using optical microscopes and scanning electron microscopy (SEM), with radioactivity recorded through …

Quantitative Analysis And Process Of High Speed Live Cell Interferometry Measurements, Daniel Guest

Theses and Dissertations

The application of auto focus, using an optical beam deflection technique, to existing live cell interferometry measurements was developed and examined. The benefit to relevant experiments, currently being performed, is shown as well as its performance across various magnifications. Enough information is given so that the system can be reproduced to fit any end users needs.

Quantitative Optical Studies Of Oxidative Stress In Rodent Models Of Eye And Lung Injuries, Zahra Ghanian

Theses and Dissertations

Optical imaging techniques have emerged as essential tools for reliable assessment of organ structure, biochemistry, and metabolic function. The recognition of metabolic markers for disease diagnosis has rekindled significant interest in the development of optical methods to measure the metabolism of the organ.

The objective of my research was to employ optical imaging tools and to implement signal and image processing techniques capable of quantifying cellular metabolism for the diagnosis of diseases in human organs such as eyes and lungs. To accomplish this goal, three different tools, cryoimager, fluorescent microscope, and optical coherence tomography system were utilized to study the …

Optical Theory Improvements To Space Domain Awareness, Tyler J. Hardy

Theses and Dissertations

This dissertation focuses on increasing the ability to detect space objects and increase Space Domain Awareness (SDA) with space surveillance sensors through image processing and optical theory. SDA observations are collected through ground-based radar and optical systems as well as space based assets. This research focuses on a ground-based optical telescope system, the Space Surveillance Telescope (SST). By increasing the number of detectable Resident Space Objects (RSOs) through image processing, SDA capabilities can be expanded. This is accomplished through addressing two main degrading factors present in typical SDA sensors; spatial undersampling in the collected data and noise models and assumptions …

Phase Sensitive Thermography Of Magnetostrictive Materials Under Periodic Excitations, Peng Yang

Theses and Dissertations

The use of giant magnetostrictive materials in actuator and sensor applications is still relatively new. Giant magnetostrictive materials, such as Terfenol-D, are unique in producing large deformation under a magnetic field. Applications of these materials in solid state actuators and transducers may require more knowledge on the interaction between geometry and material properties for a specific design. In order to gain more understanding of the magnetostriction mechanism, phase sensitive or lock-in thermography has been used to study Terfenol-D. Thermography is useful in that it allows for full field measurement of the surface of an object with a relatively simple setup. …

Laminar Flame Combustion Diagnostics Using Imaging Fourier Transform Spectroscopy, Michael R. Rhoby

Theses and Dissertations

Laminar flames are an important tool in combustion diagnostics with a host of pre-existing experimental research methods. Currently, however, no method captures time-resolved scalar profile estimates of temperature, and major species concentrations with a single measurement. This work provides IFTS with the capability to measure time-resolved 3D imaging of scalar values in laminar axisymmetric flames. This will make IFTS a useful tool for understanding combustion phenomenon, validating chemical kinetic models, verifying numerical simulations, and system performance estimate. Two algorithms are presented. The first reconstructs spectra as a function of flame period. Through selectively averaging over an ensemble of measurements, interferograms …

Particle Image Velocimetry And Analysis Methods Using Cleanly Seeded Particles In Supersonic Flow, Paul A. Gulotta

Theses and Dissertations

Particle Image Velocimetry (PIV) was successfully conducted in the Air Force Research Lab Mach 3/ Mach 6 Facility (M3M6F) for the first time. Particle response experiments evaluating the performance of dry ice particles across an oblique shock wave were conducted using a 15 degree half-wedge in nominal Mach 3 flow. Solid carbon dioxide particles are generated through rapid expansion of liquid carbon dioxide via a small nozzle within a simple shroud tube or a tube containing static mixing elements. Particles are injected directly into the settling chamber of the Mach 3 tunnel. The particle response of carbon dioxide particles is …

Variable Pathlength Cavity Spectroscopy Development Of An Automated Prototype, Ryan Schmeling

Theses and Dissertations

ABSTRACT

VARIABLE PATHLENGTH CAVITY SPECTROSCOPY

DEVELOPMENT OF AN AUTOMATED PROTOTYPE

by

Ryan Andrew Schmeling

The University of Wisconsin-Milwaukee, 2016

Under the Supervision of Professor Joseph H. Aldstadt III

Spectroscopy is the study of the interaction of electromagnetic radiation (EMR) with matter to probe the chemical and physical properties of atoms and molecules. The primary types of analytical spectroscopy are absorption, emission, and scattering methods. Absorption spectroscopy can quantitatively determine the chemical concentration of a given species in a sample by the relationship described by Beer’s Law. Upon inspection of Beer’s Law, it becomes apparent that for a given analyte concentration, …

Image-Based Bidirectional Reflectance Distribution Function Of Human Skin In The Visible And Near Infrared, Jeffrey R. Bintz

Theses and Dissertations

Human detection is an important first step in locating and tracking people in many missions including SAR and ISR operations. Recent detection systems utilize hyperspectral and multispectral technology to increase the acquired spectral content in imagery and subsequently better identify targets. This research demonstrates human detection through a multispectral skin detection system to exploit the unique optical properties of human skin. At wavelengths in the VIS and NIR regions of the electromagnetic spectrum, an individual can be identified by their unique skin parameters. Current detection methods base the skin pixel selection criteria on a diffuse skin reflectance model; however, it …

Simulation, Design, And Test Of Square, Apodized Photon Sieves For High-Contrast, Exoplanet Imaging, Thomas W.N. Dickinson

Theses and Dissertations

A photon sieve is a lightweight, diffractive optic which is well-suited to be a deployable primary for a space telescope. Point spread functions (PSFs) can be altered by shaping and apodizing an aperture, and a PSF that drops rapidly from the peak is desirable for high-contrast imaging. For this reason, square apodized photon sieves were simulated, designed, and tested for high-contrast performance and use in an exoplanet imaging telescope. These sieves were shown to outperform conventional optics and unapodized sieves for high-contrast imaging in a number of tests. New methods were developed for apodizing sieves, measuring PSFs, and characterizing high-contrast …

The Dawn Of New Quantum Dots: Synthesis And Characterization Of Ge1-Xsnx Nanocrystals For Tunable Bandgaps., Richard J. Esteves

Theses and Dissertations

Ge_1-xSn_x alloys are among a small class of benign semiconductors with composition tunable bandgaps in the near-infrared spectrum. As the amount of Sn is increased the band energy decreases and a transition from indirect to direct band structure occurs. Hence, they are prime candidates for fabrication of Si-compatible electronic and photonic devices, field effect transistors, and novel charge storage device applications. Success has been achieved with the growth of Ge_1-xSn_x thin film alloys with Sn compositions up to 34%. However, the synthesis of nanocrystalline alloys has proven difficult due to larger discrepancies (~14%) in …

Beyond Conventional C-Plane Gan-Based Light Emitting Diodes: A Systematic Exploration Of Leds On Semi-Polar Orientations, Morteza Monavarian

Theses and Dissertations

Despite enormous efforts and investments, the efficiency of InGaN-based green and yellow-green light emitters remains relatively low, and that limits progress in developing full color display, laser diodes, and bright light sources for general lighting. The low efficiency of light emitting devices in the green-to-yellow spectral range, also known as the “Green Gap”, is considered a global concern in the LED industry. The polar c-plane orientation of GaN, which is the mainstay in the LED industry, suffers from polarization-induced separation of electrons and hole wavefunctions (also known as the “quantum confined Stark effect”) and low indium incorporation efficiency that …

Experimental And Theoretical Basis For A Closed-Form Spectral Brdf Model, Samuel D. Butler

Theses and Dissertations

The microfacet class of BRDF models is frequently used to calculate optical scatter from realistic surfaces using geometric optics, but has the disadvantage of not being able to consider wavelength dependence. This dissertation works toward development of a closed-form approximation to the BRDF that is suitable for hyperspectral remote sensing by presenting measured BRDF data of 12 different materials at four different incident angles and up to seven different wavelengths between 3.39 and 10.6 micrometer. The data was intended to be fit to various microfacet BRDF models to determine an appropriate form of the wavelength scaling. However, when fitting the …

Photon Sieve Bandwidth Broadening By Reduction Of Chromatic Aberration Effects Using Second-Stage Diffractive Optics, Christopher M. Tulip

Theses and Dissertations

A photon sieve is a lightweight diffractive optic which can be useful for space-based imaging applications. It is limited by chromatic aberration and a narrow bandwidth. A Fresnel zone plate is used to counteract this effect in a manner similar to that accomplished with a traditional holographic corrector. First, a radiometric analysis established a target for bandwidth improvement. Next, a sieve was designed, fabricated, and characterized. Third, the bandwidth-broadening correction scheme was developed to correct primary chromatic aberration. Finally, a zone plate was designed, fabricated, and tested. Performance of the corrected system was measured over the target bandwidth. The corrected …

Femtosecond Laser Beam Propagation Through Corneal Tissue: Evaluation Of Therapeutic Laser-Stimulated Second And Third-Harmonic Generation, William R. Calhoun Iii

Theses and Dissertations

One of the most recent advancements in laser technology is the development of ultrashort pulsed femtosecond lasers (FSLs). FSLs are improving many fields due to their unique extreme precision, low energy and ablation characteristics. In the area of laser medicine, ophthalmic surgeries have seen very promising developments. Some of the most commonly performed surgical operations in the world, including laser-assisted in-situ keratomileusis (LASIK), lens replacement (cataract surgery), and keratoplasty (cornea transplant), now employ FSLs for their unique abilities that lead to improved clinical outcome and patient satisfaction.

The application of FSLs in medical therapeutics is a recent development, and although …

Propagation Of An Optical Vortex In Fiber Arrays With Triangular Lattices, Muhammad Abdulrahman Mushref

Theses and Dissertations

The propagation of optical vortices (OVs) in linear and nonlinear media is an important field of research in science and engineering. The most important goal is to explore the properties of guiding dynamics for potential applications such as sensing, all-optical switching, frequency mixing and modulation. In this dissertation, we present analytical methods and numerical techniques to investigate the propagation of an optical vortex in fiber array waveguides. Analytically, we model wave propagation in a waveguide by coupled mode Equations as a simplified approximation. The beam propagation method (BPM) is also employed to numerically solve the paraxial wave Equation by finite …

Nonlinear Processes In Multi-Mode Optical Fibers, Hamed Pourbeyram Kaleibar

Theses and Dissertations

Nonlinear processes in optical fibers can affect data transmission and power carried by

optical fibers and can limit the bandwidth and the capacity of optical communications.

On the other hand nonlinear phenomena could be utilized to build in-fiber all-optical

light sources and amplifiers. In this thesis new peaks inside an optical fiber have been

generated using nonlinear processes. An intense green pump laser has been launched

into a short fiber and specific modes have been excited to generate two new peaks in

red and blue wavelengths, where two pump photons are annihilated to create two new

photons in red and …

Monitoring Changes In Hemodynamics Following Optogenetic Stimulation, Seth Thomas Frye

Theses and Dissertations

The brain is composed of billions of neurons, all of which connected through a vast network. After years of study and applications of different technologies and techniques, there are still more questions than answers when it comes to the fundamental functions of the brain. This project aims to provide a new tool which can be used to gain a better understanding of the fundamental mechanisms that govern neurological processes inside the brain. In order for neural networks to operate, blood has to be supplied through neighboring blood vessels. As such, the increase or decrease in the blood supply has been …

Model Uncertainty And Test Of A Segmented Mirror Telescope, Luke C. Dras

Theses and Dissertations

The future of large aperture telescopes relies heavily on the development of segmented array designs. Today's monolithic mirror technology has reached a barrier, particularly for space-based telescopes. These large diameter, dense mirrors allow stable high-resolution imaging but are incompatible with optimized space launch. Segmented mirror telescopes are designed to balance lightweight with compact stowage. The structure necessary to support the flexible mirror array often combines isogrid geometry and complex actuation hardware. High-fidelity finite element models are commonly used to economically predict how the optics will perform under different environmental conditions. The research detailed herein integrates superelement partitioning and complexity simplifying …