Optics Commons^™

Comparison Of The Fluorescence Of Bulk Cadmium Sulfide And Cadmium Sulfide Nanoparticles, Jacob Goranson

Celebrating Scholarship and Creativity Day (2018-)

The fluorescence of bulk cadmium sulfide and cadmium sulfide nanoparticles were compared. This was done using an 800-nm, unamplified Ti:sapphire laser producing 50-fs pulses. The pulses were frequency doubled using a beta barium borate (BBO) crystal. The 400-nm beam was used to induce fluorescence in the nanoparticles, while the original 800-nm beam was used to induce fluorescence in the bulk CdS by two-photon absorption. The bulk CdS showed a single fluorescent peak at 523 nm. The nanoparticles showed fluorescence at various wavelengths across the visible spectrum. In general, the nanoparticles showed a broad fluorescent spectrum between 500 nm and 750 …

Quantification Of Surface Layer Turbulence Using Sensible Heat Values From Energy Balance Versus Aerodynamic Methods, Steven T. Fiorino, Yogendra Raut, Jaclyn Schmidt, Laura Slabaugh, Blaine Fourman, Jack E. Mccrae, Benjamin C. Wilson, Santasri R. Bose-Pillai

Faculty Publications

Surface layer optical turbulence values in the form of the refractive index structure function C_n^2 are often calculated from surface layer temperature, moisture, and wind characteristics and compared to measurements from sonic anemometers, differential temperature sensors, and imaging systems. A key derived component needed in the surface layer turbulence calculations is the sensible heat value. Typically, the sensible heat is calculated using the bulk aerodynamic method that assumes a certain surface roughness and a friction velocity that approximates the turbulence drag on temperature and moisture mixing from the change in the average surface layer vertical wind velocity. These assumptions/approximations generally …

Measurement Of Transmission Efficiency Of Blue Light Blocking Devices, Jada Lee

Honors Theses

Technology and light sources have experienced a revolution in recent years leading to the production of light emitting diode (LED) bulbs. White-light LED bulbs undergo degradation over time, leading to a rise in color temperature and a proportional increase in the emission of blue light from these bulbs. The small size of LEDs makes them the optimal choice for electronic devices because of their limited screen size. This means that blue light now exists in red, green, and blue solid-state illumination systems that did not exist a decade ago. It is debated if blue light induces toxic effects on the …

Photon Number And Waiting-Time Distributions For Superposed Light States, Eric Seglem

Physics Undergraduate Honors Theses

Nonclassical states of light are characterized by properties which can be explained by the quantum model of light but not the classical model. Such nonclassical properties may be revealed through photon counting statistics. In our research, we have examined the properties for several variations of the superposed state of light. These variations include a superposition of coherent states with evenly distributed phases (GSC state) and a superposition of squeezed vacuum states with evenly distributed phases, with particular attention given to superpositions of two coherent states (cat states). First, we calculate the photon number distribution for each of these states, and …

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, …

Manipulation Of The Magnetic Properties Of Van Der Waals Materials Through External Stimuli, Luis Martinez

Open Access Theses & Dissertations

A new revolutionary application dependent on the electron spin to carry information with greater efficiency in data storage, transfer, and processing, will rely heavily on 2D magnets and the ability to effectively control their electron spins and engineer their properties. Previously, magnetic thin films were heavily studied to achieve this goal, however, these materials came with pitfalls and lacked naturally occurring 2D magnetism. The recent discovery of intrinsic magnetism in few-layered van der Waals (vdW) magnets has inspired researchers to extensively study them because of the feasibility to exfoliate them down to a monolayer. Due to this dimensionality factor, vdW …

Development Of A High-Resolution Mid-Infrared Spectroscopy Apparatus For The Study Of Methane And Other Astrochemical Molecules., S M Shah Riyadh

Electronic Theses and Dissertations

This research documents steps towards building a novel spectroscopic technique, namely, cavity-enhanced double-resonance (CEDR) spectroscopy, for investigating methane (CH₄) and other molecules with significance in astrochemistry. These efforts focus on tackling the complexities of their ro-vibrational energy levels and the inefficiencies in analyzing vibrational spectra, particularly for molecules with high symmetry and strong intramolecular interactions. In the CEDR spectroscopy, the first photon, generated by a continuous-wave optical parametric oscillator (CW-OPO) locked to a Doppler-free saturation absorption line, excites the molecule from its ground level to a selected excited ro-vibrational (rotational-vibrational) level, e.g., that of the asymmetric CH-stretch mode. …

Investigations Of Physical Properties Of Novel Magnetic And Non- Magnetic Two-Dimensional (2d) Alloys., Mohammed Ameen Irziqat

Electronic Theses and Dissertations

This research work reports investigations of structural and physical properties of novel magnetic and non-magnetic 2D alloys. Three techniques were utilized in this investigation: Angle-resolved polarized Raman spectroscopy (ARPRS), Electrical &Thermoelectric power measurements, Magneto-optic Kerr effect (MOKE) spectroscopy. ARPRS and MOKE experiments were constructed during the course of this work. ARPRS was used to study the anisotropy of 2-dimensional black-arsenic phosphors (b-AsxP1-x) as a function of arsenic concentration (x). It was observed experimentally that all Raman modes of the studied samples with x=0, 0.4, 0.8 exhibit polarization dependence. More interestingly, the polarization dependence of Raman modes due to the vibrations …

Deterministic Global 3d Fractal Cloud Model For Synthetic Scene Generation, Aaron M. Schinder, Shannon R. Young, Bryan J. Steward, Michael L. Dexter, Andrew Kondrath, Stephen Hinton, Ricardo Davila

Faculty Publications

This paper describes the creation of a fast, deterministic, 3D fractal cloud renderer for the AFIT Sensor and Scene Emulation Tool (ASSET). The renderer generates 3D clouds by ray marching through a volume and sampling the level-set of a fractal function. The fractal function is distorted by a displacement map, which is generated using horizontal wind data from a Global Forecast System (GFS) weather file. The vertical windspeed and relative humidity are used to mask the creation of clouds to match realistic large-scale weather patterns over the Earth. Small-scale detail is provided by the fractal functions which are tuned to …

Photobiomodulation Of Bovine Oocytes During Maturation Increases Atp Content And Enhances Subsequent Embryonic Development, Kendall Richey

All Theses

Bovine in-vitro production(IVP) of embryos is a growing field for producing offspring with desirable genetics in the cattle industries. While IVP is effective, oocyte cytoplasmic maturation is compromised, and bovine oocytes matured in-vitro have reduced metabolic activity than those matured in-vivo. Mitochondria are the central unit of oocyte metabolism, producing ATP through OXPHOS. Photobiomodulation is a light treatment reported to improve metabolic activity. In five experiments, we measured the effects of photobiomodulation treatment with red LED at 16-(L-16) and 20 h(L-20) of bovine oocyte in-vitro maturation on subsequent embryonic development, mitochondrial activity and nuclear progression. Bovine COCs were aspirated …

Crystalline Colloidal Arrays: Exploring Light-Matter Interactions, Haley W. Jones

All Dissertations

Understanding and manipulating quantum light-matter interactions, especially in the context of nanostructured environments, is highly critical for technological progress and inventive solutions in the fields of telecommunications, energy-efficient lighting, and cutting-edge quantum computing technologies. The fundamental interactions of photons with a surrounding environment directly impact the performance and efficiency of devices such as lasers, light-emitting diodes (LEDs), and quantum computing elements, which leverage the unique properties of confined structured environments. Since the late 1980s, the connection between a structured environment and the decay kinetics of an embedded fluorophore has been a highly debated and unresolved topic in the literature. More …

Design, Fabrication, And Characterization Of Advanced High-Power Single-Mode 9xxnm Semiconductor Lasers, Xiaolei Zhao

All Dissertations

This thesis presents the comprehensive design, fabrication, and demonstration of advanced high-power, high-efficiency single-mode semiconductor lasers operating at a wavelength of 9xxnm. We begin with the design of the laser epitaxial structure, serving as the cornerstone for achieving high-power high-efficiency lasers. Our methodology integrates a semi-analytical calculation model, which accounts for Longitudinal Spatial Hole Burning (LSHB) and Two-Photon Absorption (TPA) effects, facilitating a thorough exploration of how design parameters influence output power and conversion efficiency. This approach offers an effective and time-efficient epitaxial structure optimization strategy compared to conventional full 3D simulation models.

Subsequently, we demonstrate high-power, high-efficiency ridge waveguide …

Investigating Turbulence Distribution In The Lower Atmosphere Using Time-Lapse Imagery From A Camera Bank, Benjamin C. Wilson, Santasri R. Bose-Pillai, Jack E. Mccrae, Steven T. Fiorino, Robert P. Freeman, Laura R. Slabaugh

Faculty Publications

The atmosphere’s surface layer (first 50–100 m above the ground) is extremely dynamic and is influenced by surface radiative properties, roughness, and atmospheric stability. Understanding the distribution of turbulence in the surface layer is critical to many applications, such as directed energy and free space optical communications. Several measurement campaigns in the past have relied on weather balloons or sonic detection and ranging (SODAR) to measure turbulence up to the atmospheric boundary layer. However, these campaigns had limited measurements near the surface. We have developed a time-lapse imaging technique to profile atmospheric turbulence from turbulence-induced differential motion or tilts between …

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 …

Deep Selenium Donors In Zngep2 Crystals: An Electron Paramagnetic Resonance Study Of A Nonlinear Optical Material, Timothy D. Gustafson, Larry E. Halliburton, Nancy C. Giles, Peter G. Schunemann, Kevin T. Zawilski, J. Jesenovec, Kent L. Averett, Jonathan E. Slagle [*]

Faculty Publications

Zinc germanium diphosphide (ZnGeP₂) is a ternary semiconductor best known for its nonlinear optical properties. A primary application is optical parametric oscillators operating in the mid-infrared region. Controlled donor doping provides a method to minimize the acceptor-related absorption bands that limit the output power of these devices. In the present study, a ZnGeP₂ crystal is doped with selenium during growth. Selenium substitutes for phosphorus and serves as a deep donor. Significant concentrations of native defects (zinc vacancies, germanium-on-zinc antisites, and phosphorous vacancies) are also present in the crystal. Electron paramagnetic resonance (EPR) is used to establish the …

Adapt Laser Shaping, Quinlin Reynolds

ATU Scholars Symposium

Investigation into producing a machine learning algorithm that allows a He-Ne laser to classify whether a produced beam shape is uniformly gaussian or not, in order to adaptively move the laser to consistently target the encoded interference pattern area. This will then result in continuous uniform beam shapes of the desired output.

Generation, Dynamics, And Interaction Of Quartic Solitary Waves In Nonlinear Laser Systems, Sabrina Hetzel

Mathematics Theses and Dissertations

Solitons are self-reinforcing localized wave packets that have remarkable stability features that arise from the balanced competition of nonlinear and dispersive effects in the medium. Traditionally, the dominant order of dispersion has been the lowest (second), however in recent years, experimental and theoretical research has shown that high, even order dispersion may lead to novel applications. Here, the focus is on investigating the interplay of dominant quartic (fourth-order) dispersion and the self-phase modulation due to the nonlinear Kerr effect in laser systems. One big factor to consider for experimentalists working in laser systems is the effect of noise on the …

Synthesis, Structural And Thermal Studies Of Dl-Alanine Potassium Di- Chromate Single Crystals, Sundararaj Lincy Mary Ponmani, Soundararajan Gnanakkan Pushpalatha Gracelin, Somasundaram Selvakumar, Subbaiah Chelladurai Vella Durai

Makara Journal of Science

Amino acids and their complexes are organic or semiorganic materials that have attracted considerable attention because they can be easily used in optical storage devices. DL-alanine is one of the rare amino acids that crystallizes in anoncentrosymmetric group. This article demonstrates how DL-alanine potassium dichromate (DAPC) single crystals have shown sufficient growth. DAPC crystals were analyzed by single crystal X-ray diffraction and powder X-ray diffraction. Using thermogravimetric analysis/differential thermal analysis (TGA/DTA) and differential scanning calorimetry, this work also examined the melting point, thermal stability, decomposition point, and other thermal parameters of the DAPC crystals. Results show that the decomposition point …

Investigation Of Gas Dynamics In Water And Oil-Based Muds Using Das, Dts, And Dss Measurements, Temitayo S. Adeyemi

LSU Master's Theses

Reliable prediction of gas migration velocity, void fraction, and length of gas-affected region in water and oil-based muds is essential for effective planning, control, and optimization of drilling operations. However, there is a gap in our understanding of gas behavior and dynamics in water and oil-based muds. This is a consequence of the use of experimental systems that are not representative of field-scale conditions. This study seeks to bridge the gap via the well-scale deployment of distributed fiber-optic sensors for real-time monitoring of gas behavior and dynamics in water and oil-based mud. The aforementioned parameters were estimated in real-time using …

Resolving The Nanoscale Structure Of Β-Sheet Peptide Self-Assemblies Using Single-Molecule Orientation–Localization Microscopy, Weiyan Zhou, Conor L. O'Neill, Tianben Ding, Oumeng Zhang, Jai S. Rudra, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

Synthetic peptides that self-assemble into cross-β fibrils are versatile building blocks for engineered biomaterials due to their modularity and biocompatibility, but their structural and morphological similarities to amyloid species have been a long-standing concern for their translation. Further, their polymorphs are difficult to characterize using spectroscopic and imaging techniques that rely on ensemble averaging to achieve high resolution. Here, we utilize Nile red (NR), an amyloidophilic fluorogenic probe, and single-molecule orientation-localization microscopy (SMOLM) to characterize fibrils formed by the designed amphipathic enantiomers KFE8^L and KFE8^D and the pathological amyloid-beta peptide Aβ42. Importantly, NR SMOLM reveals the helical (bilayer) …

6d Single-Fluorogen Orientation-Localization Microscopy For Elucidating The Architecture Of Beta-Sheet Assemblies And Biomolecular Condensates, Tingting Wu, Weiyan Zhou, Jai S. Rudra, Rohit V. Pappu, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

We develop six-dimensional single-molecule orientation-localization microscopy (SMOLM) to measure the 3D positions and 3D orientations simultaneously of single fluorophores. We show how careful optimization of phase and polarization modulation components can encode phase, polarization, and angular spectrum information from each fluorescence photon into a microscope’s dipole-spread function. We used the transient binding and blinking of Nile red (NR) to characterize the helical structure of fibrils formed by designed amphipathic peptides, KFE8^L and KFE8^D, and the pathological amyloid-beta peptide Aβ42. We also deployed merocyanine 540 to uncover the interfacial architectures of biomolecular condensates.

Laboratory Exercise For The Radiometry Student, Michael A. Marciniak

Faculty Publications

The U.S. Air and Space Forces require optical expertise among their personnel. The Air Force Institute of Technology offers a graduate optics curriculum, which includes a three-course sequence to educate students in the optical concepts of radiometry and radiometric instrumentation. We find radiometry is often a deceptively difficult concept for students to master. To address this, we have developed an experiment in our optics-laboratory coursework to help them gain this mastery. A Fourier-transform infrared spectrometer (FTS) is used to collect spectral data from an unknown sample. FTS calibration and data collection are discussed here, as are the two specific samples …

Modelling Hoe Performance With An Extended Source; Experimental Investigation Using Misaligned Point Sources, Jorge Lasarte, Kevin Murphy, Izabela Naydenova, Maria Victoria Collados, Jesús Atencia, Suzanne Martin

Articles

Holographic optical elements (HOEs) have the potential to enable more compact, versatile, and lightweight optical designs, but many challenges remain. Volume HOEs have the advantage of high diffraction efficiency, but they present both chromatic selectivity and chromatic dispersion, which impact their use with wide spectrum light sources. Single-color light emitting diode (LED) sources have a narrow spectrum that reduces these issues and this makes them better suited for use with volume HOEs. However, the LED source size must be taken into consideration for compact volume HOE-LED systems. To investigate the design limits for compact HOE-LED systems, a theoretical and experimental …

Two-Photon Absorption And Fluorescence Of Cadmium Sulfide, Jacob Goranson, Gregory J. Taft

Physics Faculty Publications

The two-photon absorption and fluorescence of bulk cadmium sulfide were studied using 50-fs, 800-nm pulses from an unamplified Ti:sapphire laser. The fluorescence spectrum was measured to have a main peak at 522 nm, and the power of the fluorescence was shown to vary quadratically with the 800-nm beam power. This supports the theory that the fluorescence is excited by two-photon absorption and confirms previous work done with longer duration, higher energy excitation pulses. Pump-probe measurements provided additional confirmation of the two-photon absorption. Measured spectral broadening of the wings of the laser spectrum also was observed, which likely is due to …

Residual Optical Absorption From Native Defects In Cdsip2 Crystals, Timothy D. Gustafson, Nancy C. Giles, Elizabeth M. Scherrer, Kevin T. Zawilski, Peter G. Schunemann, Kent L. Averett, Jonathan E. Slagle, Larry E. Halliburton

Faculty Publications

CdSiP₂ crystals are used in optical parametric oscillators to produce tunable output in the mid-infrared. As expected, the performance of the OPOs is adversely affected by residual optical absorption from native defects that are unintentionally present in the crystals. Electron paramagnetic resonance (EPR) identifies these native defects. Singly ionized silicon vacancies (V^-_Si) are responsible for broad optical absorption bands peaking near 800, 1033, and 1907 nm. A fourth absorption band, peaking near 630 nm, does not involve silicon vacancies. Exposure to 1064 nm light when the temperature of the CdSiP₂ crystal is near 80K converts …

Exciton Dynamics, Interaction, And Transport In Monolayers Of Transition Metal Dichalcogenides, Saroj Chand

Dissertations, Theses, and Capstone Projects

Monolayers Transition metal dichalcogenides (TMDs) have attracted much attention in recent years due to their promising optical and electronic properties for applications in optoelectronic devices. The rich multivalley band structure and sizable spin-orbit coupling in monolayer TMDs result in several optically bright and dark excitonic states with different spin and valley configurations. In the proposed works, we have developed experimental techniques and theoretical models to study the dynamics, interactions, and transport of both dark and bright excitons.

In W-based monolayers of TMDs, the momentum dark exciton cannot typically recombine optically, but they represent the lowest excitonic state of the system …

Development Of Advanced Instrumentation For High-Enthalpy Flow Characterization For The Onr-Uta Arc-Jet ”Leste” Facility, Ian Raybon

Mechanical and Aerospace Engineering Dissertations - Archive

Sustained hypersonic flight is an exceedingly challenging task comprised of a myriad of complex physical processes. At hypersonic speeds, which is defined by the presence of unique phenomena like high-temperature nonequilibrium flow, viscous and vorticity interactions, and thin shock layers, which are not seen in supersonic, transonic, or subsonic vehicles, the vehicle design is principally driven by the high levels of aerodynamic heating caused by the conversion of kinetic energy to internal energy. Gaining an understanding of how these physical processes interact with each other is required to develop a design methodology for this class of vehicles. Arc-jet wind tunnels …

Optical Seed Development For Yb-Fiber Laser, James G. Brutus

Graduate Thesis and Dissertation 2023-2024

Master Oscillator Power Amplifiers (MOPA) are laser systems that utilize a seed and pump amplification system to boost the output power of high-quality lower power seeding signals. MOPAs can generate high gain while avoiding many of the nonlinearities that negatively affect resonance-based lasers that are known to feature higher internal intensities. Additionally, MOPAs provide an easy alternative to the construction of novel laser technologies for higher output power as they can be easily combined with existing laser sources to amplify their output power.

This thesis outlines the design of an ytterbium-doped fiber laser (YDFL), featuring a MOPA architecture. The YDFL …

Visual Experience Enhancement In Augmented Reality Displays, Qian Yang

Graduate Thesis and Dissertation 2023-2024

In the dynamic arena of display technology, augmented reality (AR) displays represent a pivotal advancement, seamlessly bridging the digital and physical worlds. This dissertation delves into the realm of AR display technologies, spotlighting the challenges and limitations of current systems, including transparent and near-eye displays, and proposes innovative solutions to enhance user experience and display performance. With a focus on overcoming issues such as diffraction-induced image blur, the trade-off between resolution and field of view (FoV) in near-eye displays, and FoV constraints in waveguide-based displays, this research introduces new evaluation methods, optimization techniques, and system designs. First, the dissertation presents …

Dual Frequency Comb Mid-Ir – Thz Spectroscopy, Dmitrii Konnov

Graduate Thesis and Dissertation 2023-2024

The optical frequency comb is a coherent light source whose spectrum consists of hundreds of thousands perfectly equidistant narrow frequency components and precisely expressed in just two radio frequencies. Even though optical frequency combs were developed 25 years ago, that led to the Nobel Prize in Physics 2005, only recently there was a significant progress in generating broadband optical frequency combs in the mid-infrared. These achievements became possible due to the development of new types of robust fiber and solid-state lasers and the efficient downconverting of their frequencies through different techniques based on advanced nonlinear crystals. In this dissertation, I …