Optics Commons^™

Rapid-Prototyping Nanofabrication: Lcd-Based Projection Lithography And Physical Vapor Deposition, Sabeel Saleem Mohammmed

University Honors Theses

The semiconductor industry's continued growth, driven in large part by demand for artificial intelligence hardware, has highlighted the need for greater workforce development in regions adjacent to major fabrication centers like Oregon's Silicon Forest. This capstone project lays the groundwork for a small scale and student led semiconductor fabrication lab at Portland State University by demonstrating two of the core steps in chip manufacturing: photolithography and thin film deposition. Rather than relying on conventional fixed reticles, this work explores a unique, low cost approach to patterning that uses an ultraviolet-compatible liquid crystal display (LCD) as a programmable reticle, allowing arbitrary …

Improving The Reliability And Performance Of A Supersonic Indraft Tube Wind Tunnel, Christian J. Kaml

Master's Theses

Access to supersonic testing is increasing in demand, and wind tunnels remain one of the safest and most cost-effective methods for gathering high-speed flow data. Despite being more economical than alternative options, supersonic wind tunnel facilities often require substantial investment to construct, operate, and maintain.

The novel indraft tube tunnel architecture was conceived as a high-speed flow testbed that incorporates features of both Ludwieg tubes and indraft wind tunnels to maintain costs low enough to be accessible even to small universities. This design was first developed and tested in 2018 at California Polytechnic State University, featuring a cost per test …

Investigation Of Laser Based Flow Diagnostics With Metastable Argon, Sterling S. Gordon

Physics Theses & Dissertations

The overarching motivation of this work is the development of seedless, non-intrusive, laser-based diagnostics for supersonic airflow in wind tunnels. To advance this goal, this dissertation fo-cuses on three-photon excitation in a research-grade argon beam within a tabletop vacuum system, which offers a controlled environment for testing and refining the approach. The chosen excitation scheme drives argon atoms to the 3d[5/2]₃ state using a pulsed Ti:Sapphire laser system, enabling time-of-flight (ToF) measurements on atoms that subsequently undergo a multi-step decay to the metastable 4s[3/2]₂ state. Although full realization of this excitation scheme was hindered by technical …

Active Measurement Of A Micron-Order Gap Under High-Speed And High-Temperature Conditions, Andrew Becker

Doctoral Dissertations and Master's Theses

The hypersonic regime poses numerous challenges that researchers face in the development of hypersonic flight vehicles. Due to their excellent thermomechanical properties, ultra-high-temperature ceramics (UHTCs) have risen as a promising solution to act as a protective barrier between the harsh environment and surface materials of these flight bodies. The mechanical operation of a portable hypersonic simulation device was developed in-house and tested at Argonne National Laboratories (ANL) to gather in-situ material response of prospective UHTC samples when exposed to a hypersonic regime. An edge detection-based algorithm was developed and used in LabVIEW to monitor the health and operation of the …

Enhanced Point Cloud Generation From A Novel 360° Underwater Lidar, Olagoke E. Daramola

Dissertations

This dissertation presents novel algorithms to improve the mapping capabilities of a 360-degree underwater Pulsed Laser Line Scanner LiDAR (PLLS-360°). Due to its 360° field-of-view (FOV), the PLLS-360° is a compact full-waveform omnidirectional imager suitable for seafloor mapping, underwater asset inspection, object detection, ice-sheet mapping, and construction progress monitoring. The proposed methodology includes an improved waveform fitting technique for saturated waveform recovery, detection array response correction, radiometric corrections, and fusion of LiDAR and sonar bathymetric datasets. The first part of this dissertation assesses the LiDAR’s performance and describes how the data for this unique 360° FOV architecture is processed. The …

Advancing Real-World Implementation Of The Well Optimized Linear Finder (Wolf) High-Speed Atmospheric Turbulence Compensation Method, Timothy Evan Coon

Theses and Dissertations

This dissertation advances the real-world implementation of the Well Optimized Linear Finder (WOLF) method for high-speed Atmospheric Turbulence Compensation (ATC). Atmospheric turbulence introduces phase aberrations into optical wavefronts and degrades image quality in terrestrial imaging systems. Traditional phase diversity methods are computationally intensive and poorly suited to real-time operation. The WOLF method addresses these limitations through a novel, point-wise formulation of the optical transfer function (OTF) as a structured autocorrelation of the generalized pupil function (GPF). This formulation enables the estimation of phase aberrations at individual spatial coordinates with distributed computational complexity.

The research begins by developing a MATLAB-based simulation …

The Use Of Two-Dimensional Detectors For Snapshot And High Accuracy Imaging Ellipsometry, Jeremy A. Vanderslice

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Ellipsometry is a powerful and sensitive optical technique used to characterize thin film thickness and optical properties by measuring changes in the polarization state of light upon reflection or transmission. This dissertation investigates novel ellipsometry configurations that use two-dimensional detectors to enhance measurement speed, spatial resolution, or accuracy of ellipsometry measurements. The study involves the development of three different ellipsometry configurations, encompassing mechanical prototypes, mathematical models, and test measurements to evaluate each system.

Advisor: Jeffrey Shield

Studies Of Exotic Electronic, Optical, And Electrochemical Properties In Nanoparticle Assembly And Graphene, Jay Min Lim

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

It is well known that exotic properties and phenomena emerge as structural dimensions shrink to nanoscales. We self-assembled one-dimensional chains of gold nanoparticles in solution and quantified the growth process by monitoring the redshift of localized surface plasmon resonance (LSPR). Curiously, the redshift stopped while the chains continued to rearrange as manifested by gradual reduction in the LSPR peak. Using electromagnetic simulations, we quantitatively explained the phenomena as a rapid “addition-polymerization” followed by a sharp transition to “condensation-process.” Next, recognizing the significant electric field enhancement in the interparticle gap, a photoluminescent-active Eu³⁺ ion was used to probe Surface-Enhanced Photoluminescence …

Focused Led Sintering, Dylan Defazio, Nilav Maulik, Branden Majors, Michael Fontillas

Mechanical Engineering

This report provides a detailed overview of the final design of our light-emitting diode (LED) focusing system. Our system incorporates a converging lens and a specially designed "glass funnel," which acts as a thick fiber optic that narrows the light to a fine point through internal reflection. The glass components of our system are precisely housed in a part made using advanced computer-numeric controlled (CNC) Mill and CNC Lathe manufacturing processes. This ensures high precision and durability of the overall system. Our LED focusing system is designed with a 60-watt stage light. The decision to use a glass funnel as …

Numerical Simulation Of Laser Induced Elastic Waves In Response To Short And Ultrashort Laser Pulses., Alireza Zarei

All Dissertations

In an era of intensified market competition, the demand for cost-effective, high-quality, high-performance, and reliable products continues to rise. Meeting this demand necessitates the mass production of premium products through the integration of cutting-edge technologies and advanced materials while ensuring their integrity and safety. In this context, Nondestructive Testing (NDT) techniques emerge as indispensable tools for guaranteeing the integrity, reliability, and safety of products across diverse industries.

Various NDT techniques, including ultrasonic testing, computed tomography, thermography, and acoustic emissions, have long served as cornerstones for inspecting materials and structures. Among these, ultrasonic testing stands out as the most prevalent method, …

Measuring Soot In A Novel Configuration For Diffusion Flames Fueled By Ethylene Doped With Iso-Dodecane, Christian Bjork

Honors Scholar Theses

Sustainable Aviation Fuels (SAFs) are seen as the path forward for decarbonizing hard-to-electrify sectors. Using SAFs over traditional fossil fuels abates carbon dioxide emissions but still may present soot emission problems. A milestone in the abatement of soot would be understating its formation mechanisms.

This study aims to quantify soot products resulting from an ethylene flame doped with iso-dodecane, a surrogate SAF component. The burner selected for the investigation is the novel Planar Mixing Layer Flame (PMLF) which allows the tracking of soot formation with the height above the burner (HAB) in a stable diffusion flame. A baseline ethylene-fueled flame …

Femtosecond Laser Shock Peening And The Dynamics Of Femtosecond Laser-Induced Shock Waves, Yuxin Li

All Dissertations

Laser shock peening (LSP) is an important material surface strengthening technique that uses laserinduced shock waves to cause severe plastic deformation near material surfaces. It can significantly improve material properties like hardness, strength, fatigue life, and corrosion resistance and is widely used in industrial sectors such as automotive, aerospace, nuclear, and medical areas. The conventional nanosecond laser shock peening (ns-LSP) has demonstrated effectiveness but faces challenges such as complex setup, low throughput, high energy consumption, and inflexibility for complex geometries. Femtosecond laser shock peening (fs-LSP) offers a promising alternative to overcome these issues, thanks to its ultra-high laser intensity and …

Photonic Sensors Based On Integrated Ring Resonators, Jaime Da Silva

Mechanical Engineering Research Theses and Dissertations

This thesis investigates the application of integrated ring resonators to different sensing applications. The sensors proposed here rely on the principle of optical whispering gallery mode (WGM) resonance shifts of the resonators. Three distinct sensing applications are investigated to demonstrate the concept: a photonic seismometer, an evanescent field sensor, and a zero-drift Doppler velocimeter. These concepts can be helpful in developing lightweight, compact, and highly sensitive sensors. Successful implementation of these sensors could potentially address sensing requirements for both space and Earth-bound applications. The feasibility of this class of sensors is assessed for seismic, proximity, and vibrational measurements.

Modeling, Simulation And Control Of Microrobots For The Microfactory., Zhong Yang

Electronic Theses and Dissertations

Future assembly technologies will involve higher levels of automation in order to satisfy increased microscale or nanoscale precision requirements. Traditionally, assembly using a top-down robotic approach has been well-studied and applied to the microelectronics and MEMS industries, but less so in nanotechnology. With the boom of nanotechnology since the 1990s, newly designed products with new materials, coatings, and nanoparticles are gradually entering everyone’s lives, while the industry has grown into a billion-dollar volume worldwide. Traditionally, nanotechnology products are assembled using bottom-up methods, such as self-assembly, rather than top-down robotic assembly. This is due to considerations of volume handling of large …

Optical Fiber Tip Micro Anemometer, Jeremiah C. Williams, Hengky Chandrahalim

AFIT Patents

A passive microscopic flow sensor includes a three-dimensional microscopic optical structure formed on a cleaved tip of an optical fiber. The three-dimensional microscopic optical structure includes a post attached off-center to and extending longitudinally from the cleaved tip of the optical fiber. A rotor of the three-dimensional microscopic optical structure is received for rotation on the post. The rotor has more than one blade. Each blade has a reflective undersurface that reflects a light signal back through the optical fiber when center aligned with the optical fiber, the blades of the rotor shaped to rotate at a rate related to …

Temperature-Immune Self-Referencing Fabry–Pérot Cavity Sensors, Hengky Chandrahalim, Jonathan W. Smith

AFIT Patents

A passive microscopic Fabry-Pérot Interferometer (FPI) sensor an optical fiber a three-dimensional microscopic optical structure formed on a cleaved tip of an optical fighter that reflects a light signal back through the optical fiber. The reflected light is altered by refractive index changes in the three-dimensional structure that is subject to at least one of: (i) thermal radiation; and (ii) volatile organic compounds.

Temperature-Immune Self-Referencing Fabry–Pérot Cavity Sensors, Hengky Chandrahalim, Jonathan W. Smith

AFIT Patents

A passive microscopic Fabry-Pérot Interferometer (FPI) sensor an optical fiber a three-dimensional microscopic optical structure formed on a cleaved tip of an optical fighter that reflects a light signal back through the optical fiber. The reflected light is altered by refractive index changes in the three-dimensional structure that is subject to at least one of: (i) thermal radiation; and (ii) volatile organic compounds.

Design Of A 5 Degree Of Freedom Kinematic Stage For The Dual Crystal Backlighter Imager Diagnostic, Nicholas Nguyen

Master's Theses

The National Ignition Facility (NIF) is home to the world’s most energetic laser. The facility is one of the leading centers in inertial confinement fusion (ICF) experiments to research and understand sustainable fusion energy. To fully document and understand the physics occurring during experiments, precise diagnostics are used for a wide range of purposes. One diagnostic, the crystal backlighter imager (CBI), allows for X-ray imaging of the target at late stages of its implosion.

The aim of this project was to increase the current capabilities of the CBI diagnostic with the addition of a second crystal. This thesis focuses on …

Automating 35mm Photographic Film Digitization: X-Y Table Capture System Design And Assessment, Michael J. Bennett

Published Works

35mm still image formats are some of the most abundant photographic film types in cultural heritage collections. However, their special handling needs coupled with high resolution digital capture requirements have traditionally posed logistical constraints with regard to the formats’ digitization at scale. Through the use of a programmable X-Y table camera capture system, both slide and strip 35mm photographic film can be digitized in an automated fashion following Federal Agencies Digitization Guidelines (FADGI).

Construction Of A Hyperspectral Imager Using 3d-Printed And Off-The-Shelf Components, Joshua Moorhouse

Mechanical Engineering Undergraduate Honors Theses

The Arkansas Center for Space and Planetary Sciences is working in collaboration with the Mechanical Engineering department to create a relatively cheap and modifiable hyperspectral imager. It is constructed using 3D-printed and off-the-shelf components from Edmund Optics and Amazon. The iteration created in this paper delivers spectrograms in the visible spectrum. The long-term goals of the camera are to create hyperspectral images from these spectrograms and to advance the imager into the infrared and near-infrared spectra. This imager is being developed to be used in the Arkansas Center for Space and Planetary Sciences environmental test chambers to further the scientific …

Dual-Axis Solar Tracker, Bryan Kennedy

All Undergraduate Projects

Renewable energies, and fuels that are not fossil fuel-based, are one of the prolific topics of debate in modern society. With climate change now becoming a primary focus for scientists and innovators of today, one of the areas for the largest amount of potential and growth is that of the capturing and utilization of Solar Energy. This method involves using a mechanical system to track the progression of the sun as it traverses the sky throughout the day. A dual-axis solar tracker such as the one designed and built for this project, can follow the sun both azimuthally and in …

Development Of High-Speed Photoacoustic Imaging Technology And Its Applications In Biomedical Research, Yun He

McKelvey School of Engineering Graduate Student Theses & Dissertations

Photoacoustic (PA) tomography (PAT) is a novel imaging modality that combines the fine lateral resolution from optical imaging and the deep penetration from ultrasonic imaging, and provides rich optical-absorption–based images. PAT has been widely used in extracting structural and functional information from both ex vivo tissue samples to in vivo animals and humans with different length scales by imaging various endogenous and exogenous contrasts at the ultraviolet to infrared spectrum. For example, hemoglobin in red blood cells is of particular interest in PAT since it is one of the dominant absorbers in tissue at the visible wavelength.The main focus of …

A Rotating Aperture Mask For Small Telescopes, Edward L. Foley

Master's Theses

Observing the dynamic interaction between stars and their close stellar neighbors is key to establishing the stars’ orbits, masses, and other properties. Our ability to visually discriminate nearby stars is limited by the power of our telescopes, posing a challenge to astronomers at small observatories that contribute to binary star surveys. Masks placed at the telescope aperture promise to augment the resolving power of telescopes of all sizes, but many of these masks must be manually and repetitively reoriented about the optical axis to achieve their full benefits. This paper introduces a design concept for a mask rotation mechanism that …

Microextrusion 3d Printing Of Optical Waveguides And Microheaters, Edidiong Nseowo Udofia

Graduate Theses and Dissertations

The drive for smaller and more compact devices presents several challenges in materials and fabrication strategies. Although photolithography is a well-developed method for creating microdevices, the disparate requirements in fabrication strategies, material choices, equipment and process complexities have limited its applications. Microextrusion printing (μEP) provides a promising alternative for microfabrication. Compared to the traditional techniques, the attractions lie in the wide range of printable material choice, greater design freedom, fewer processing steps, lower cost for customized production, and the plurality of compatible substrates. However, while extrusion-based 3D printing processes have been successfully applied at the macroscale, this seeming simplicity belies …

Development Of A Ground-Based Aerial-Tracking Instrument For Open-Path Spectroscopy To Monitor Atmospheric Constituents, Haden Hodges

Civil Engineering Undergraduate Honors Theses

A ground-based aerial-tracking instrument, known as the Ground Tracker, designed to provide spectral data to quantify greenhouse gases is under development. The Ground Tracker includes an Optical System including a high power rifle scope, video camera, and spectrometer used to locate an active light source from the Emitter, and collect spectral data by utilizing an actuating mirror. The implementation of this instrument could be made low cost by utilizing existing weather balloon infrastructure to allow the Emitter to be placed into the lower stratosphere. The recovery of the emitter will be possible by tracking the GPS coordinates. Weather balloon instrument …

Construction Of A Hyperspectral Camera Using Off-The-Shelf Parts And 3d-Printed Parts, Connor Heo

Mechanical Engineering Undergraduate Honors Theses

The Arkansas Center for Space and Planetary Sciences (ACSPS) is working together with the Mechanical Engineering Department to build a modifiable camera with 3D-printed parts and off-the-shelf parts (sourced from Edmund Optics and Amazon). The design is to be readily changeable, primarily with the 3D printed parts, as to accommodate new ideas and functionalities in the future. Ultimately, the camera should be relatively cheap while maintaining functionality for proposed use cases. Earlier versions of the design will be tested extensively and rapidly updated in the ACSPS labs with benchtop testing. This will involve subjects with both visible and infrared emissions, …

Optical Micro-Seismometer Based On Evanescent Field Perturbation Of Whispering Gallery Modes, Jaime Da Silva

Mechanical Engineering Research Theses and Dissertations

This thesis proposes a light-weight, compact, and accurate optical micro-seismometer that could be used in many applications, such as planetary exploration. The sensor proposed here is based on the principle of whispering gallery optical mode (WGM) resonance shifts of a dielectric micro-resonator due to disturbances of its evanescent field. The micro-seismometer could be used in place of the traditional bulky seismometers. The design of a waveguide-resonator and mechanical structure to disturb the evanescent field are presented. A proof-of-concept a seismometer model that uses a 5µm ring resonator is numerically tested with actual seismic data. The results show that a WGM-based …

Superpositioning High Power Lasers For Mid-Air Image Formation, Auston Viotto

UNO Student Research and Creative Activity Fair

Abstract

This research evaluates different methods to create voxels, 3-dimensional pixels, in air without the need for special glasses or reflections off of surfaces. Research on the advantages of superimposing or the culmination, focusing, of laser light will be conducted. The point of superpositioning/culmination will be evaluated by the brightness of the voxel due to the Rayleigh Scatter Effect. The voxel’s brightness is dependent on the laser output strength and inversely proportional to its wavelength. Once a superimposed/culminated voxel has been created in the lab the next step will be to manipulate the location of the voxel through 3-dimensional space. …

Superpositioning High Power Lasers For Mid-Air Image Formations, Auston Viotto

UCARE: Research Products

This research evaluates different methods to create voxels, 3-dimensional pixels, in air without the need for special glasses or reflections off of surfaces. Research on the advantages of superimposing or the culmination, focusing, of laser light will be conducted. The point of superpositioning/culmination will be evaluated by the brightness of the voxel due to the Rayleigh Scatter Effect. The voxel’s brightness is dependent on the laser output strength and inversely proportional to its wavelength. Once a superimposed/culminated voxel has been created in the lab the next step will be to manipulate the location of the voxel through 3-dimensional space. This …

Optical Analysis And Fabrication Of Micro And Nanoscale Plasmonically Enhanced Devices, Avery M. Hill

Physics Undergraduate Honors Theses

Plasmonic nanostructures have been shown to act as optical antennas that enhance optical devices due to their ability to focus light below the diffraction limit of light and enhance the intensity of the incident light. This study focuses on computational electromagnetic (CEM) analysis of two devices: 1) GaAs photodetectors with Au interdigital electrodes and 2) Au thin-film microstructures. Experiments showed that the photoresponse of the interdigital photodetectors depend greatly on the electrode gap and the polarization of the incident light. Smaller electrode gap and transverse polarization give rise to a larger photoresponse. It was also shown that the response from …