Optics Commons^™

A Comprehensive Study On The Use Of Sub-Coherent Self Heterodyne Linewidth Estimations, Genevieve Gutierrez

UNLV Theses, Dissertations, Professional Papers, and Capstones

A fundamental requirement for many precision spectroscopic applications is the development of stable lasers with narrow linewidths. However, accurately verifying laser linewidths becomes increasingly challenging as the linewidth decreases. In the field of frequency metrology, the delayed self-heterodyne technique has long been regarded as one of the most reliable and accessible methods for linewidth characterization, favored for its low equipment cost and reproducible results. Traditionally, self-heterodyne measurements employ an optical delay line significantly longer than the coherence length of the laser, with analysis performed via either the instantaneous power spectral density or the noise power spectral density. However, the use …

Non-Linear Atom-Laser Interactions Using Rubidium Pump-Probe Spectroscopy, Grace Neil

Beyond: Undergraduate Research Journal

An experiment was performed to demonstrate the pump-probe spectroscopy of Rubidium (Rb) vapor, revealing the nonlinear atom-laser interactions in the 5S1/2 ↔ 5D5/2 transition in Rb that can be used to generate quantum entanglement between two laser beams. The setup included a tunable infrared diode laser, optical mirrors, photodiode-detectors, a beam-splitter, and a temperature- regulated rubidium gas chamber, all of which are controlled by the TeachSpin laser controller and monitor. The output from the laser-diode was split into a pump (90%) and a signal probe (10%), which intersected in counter-propagating directions inside the Rubidium chamber. The analysis shows that in …

Method For Target Detection In A High Noise Environment Through Frequency Analysis Using An Event-Based Vision Sensor, Will Johnston, Shannon Young, David Howe, Rachel Oliver, Zachary Theis, Brian Mcreynolds, Michael L. Dexter

Faculty Publications

Event-based vision sensors (EVSs), often referred to as neuromorphic cameras, operate by responding to changes in brightness on a pixel-by-pixel basis. In contrast, traditional framing cameras employ some fixed sampling interval where integrated intensity is read off the entire focal plane at once. Similar to traditional cameras, EVSs can suffer loss of sensitivity through scenes with high intensity and dynamic clutter, reducing the ability to see points of interest through traditional event processing means. This paper describes a method to reduce the negative impacts of these types of EVS clutter and enable more robust target detection through the use of …

Volumetric Imaging Of Cellular Dynamics Using Light-Sheet Microscopy: From Subcellular Structures To Whole Organisms, Md Nasful Huda Prince

Optical Science and Engineering ETDs

Advancing biomedical imaging requires platforms that combine high-resolution, speed, and stability across biological scales. This dissertation presents three innovations designed to address limitations of conventional light-sheet and oblique plane imaging. First, we introduce Reflected Inline Detection in Epi-Oblique Plane Microscopy (RIDE-OPM), a compact and drift-resistant system that eliminates a tertiary detection path while maintaining alignment flexibility, enabling robust long-term live imaging. Second, we present a high-speed Axially Swept Light-Sheet Microscopy (ASLM) platform for cleared tissues, using dual foci and synchronized sweeping to achieve isotropic sub-micron resolution at up to 40 frames-per-second, a fourfold improvement over standard ASLM. Integrated with a …

Guided Modes Through The Dual Perspectives Of Geometrical Optics And Wave Equation, Mason Spears

Mathematics and Statistics Undergraduate Departmental Honors Theses

In an optical waveguide, only finitely many electric field intensity profiles travel without loss, and these are aptly named guided modes. This paper uses fundamental concepts from the two paradigms of interpreting light, geometrical and physical optics, to derive guided modes axiomatically. First, basic principles of geometrical optics are demonstrated in a slab waveguide to explain characteristics of optical waveguides such as total internal reflection and numerical aperture. Dispersion curves are assembled from the same principles and used to show that only finitely many guided modes exist for a given waveguide. Next, Maxwell’s equations are used to derive the famous …

Quantum Dot Light Emitting Diodes As A Light Source For Photodynamic Therapy, Hamid El Hamidi

Graduate Doctoral Dissertations

ABSTRACT:

QUANTUM DOT LIGHT EMITTING DIODES AS A LIGHT SOURCE FOR PHOTODYNAMIC THERAPY

Photodynamic therapy is a cancer treatment modality that involves the accumulation of a photosensitizer, exposure to visible light, and the presence of oxygen, resulting in the formation of highly reactive and cytotoxic singlet oxygen. PDT has been shown to be more effective as the fluence rate decreases due to oxygen availability and the absence of photobleaching. On the other hand, Quantum Dot Light Emitting Diodes QLEDs- a new form of light source based on nanoparticles (quantum dots)- emerge as a potentially advantageous light source for certain types …

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 …

A Study On The Propagation And Exploitation Of Structured Light In Underwater Turbulence, Jaxon P. Wiley

All Dissertations

The development and optimization of optical systems will play a pivotal role in the continued exploration and exploitation of the world’s underwater environments. These systems offer advantages in many sectors, and includes applications in areas such as high-speed communication, advanced sensing and imaging, and environmental characterization and monitoring. Underwater environments offer a plethora of challenges, however, and mitigating these obstacles remains an arduous task. In this work, the inherent advantages of structured light are leveraged to optimize optical system performance through non-ideal underwater conditions. Additionally, fundamental relationships between the generation of specified structured modes and their interactions with complex environments …

Phase Nanoscopy With Correlated Frequency Combs, Xiaobing Zhu

Optical Science and Engineering ETDs

In this dissertation a sensing method applying to any physical quantity that modifies optical phase is developed. Two pulses are produced inside a synchronously pumped Optical Parametric Oscillator, generating two identical, undistinguishable frequency combs. The physical quantity to be measured applies a small phase shift/round trip to one of the pulses, resulting in a frequency shift of the corresponding comb. The latter frequency is measured as a beat by interfering the two combs on a detector. A world record resolution, close to the quantum limit, of 0.033 nanoradian (corresponding to 0.006 fm in displacement) is achieved. A detailed analysis of …

Advancing Diamond Quantum Sensors: Isotropic Flux Concentrators And Phase Noise Mitigation, Maziar Saleh Ziabari

Optical Science and Engineering ETDs

Two methods for improving the sensitivity of nitrogen vacancy quantum sensors in diamond are explored. First, by passively concentrating the magnetic flux, three orthogonally oriented ferrite truncated cone pairs amplify the field isotropically by 19 times, allowing measurement of Earth's field without a bias field and increasing sensitivity. Through thorough analysis, modeling and tuning a novel 3-dimensional flux concentrator system, we achieve a fractional standard deviation of less than 1% anisotropy and quantify minimal deadzones and ambient temperature-limited variations below 40 nT/hour. Second, we characterize, model and calculate phase noise in NV experiments, which in NV sensors is effectively indistinguishable …

3d Solid Models, Bradley M. Ratliff

Model Desert Terrain Monochromatic DoT Dataset

3D solid models for model vehicles, target panels, objects, and the desert terrain model in STL file format.

Ground Truth Images, Bradley M. Ratliff

Model Desert Terrain Monochromatic DoT Dataset

Laboratory and scenario ground truth images for the Model Desert Terrain Monochromatic DoT dataset.

Polarimetric Data: Scenario 01, Bradley M. Ratliff

Model Desert Terrain Monochromatic DoT Dataset

Polarimetric data Scenario 01 collected within the Automated Remote Sensing Solar Simulation Lab at the University of Dayton. The data were collected using a visible monochromatic division-of-time imaging polarimeter. The dataset is parameterized across different sensor, scene, and illumination geometries that mimic outdoor solar irradiance conditions.

Data Annotations, Bradley M. Ratliff

Model Desert Terrain Monochromatic DoT Dataset

Pixel-wise object masks for each polarimetric scene in ASL file format for the Model Desert Terrain Monochromatic DoT data.

Dataset Description, Bradley M. Ratliff

Model Desert Terrain Monochromatic DoT Dataset

Polarimetric dataset containing data collected within the Automated Remote Sensing Solar Simulation Lab at the University of Dayton. The data were collected using a visible monochromatic division-of-time imaging polarimeter. A model desert terrain model was constructed and imaged for eight different scenarios consisting of different model panel and vehicle targets. The dataset is parameterized across different sensor, scene, and illumination geometries that mimic outdoor solar irradiance conditions.

Yb:Ylf Optical Cryocoolers: Saturation Effects, Pump Management, Robust Thermometry, And Novel Architectures, Jackson Kock

Optical Science and Engineering ETDs

Solid-state optical refrigeration using anti-Stokes fluorescence offers a compact, vibration-free route to cryogenic cooling. This dissertation advances ytterbium-doped yttrium lithium fluoride (Yb:YLF) refrigerators, achieving a world record payload cooling temperature of 124 K by addressing key limitations due to absorption saturation. An expanded theoretical model incorporating saturation effects enables accurate predictions of cooling performance under high pump intensities. To improve pump control, a modeling framework for astigmatic Herriott cells was developed, revealing how beam clipping and intensity impact coupling efficiency. A novel fluorescence-based thermometry method was also established, providing accurate, orientation-independent temperature sensing by overcoming reabsorption and crystal orientation. Finally, …

Investigation Of A Polymer-Based Holographic Grating For Visible Light Dosimetry Using A Bleachable Dye, Saoirse Maher, Denise Denning, Jackie Mccavana Dr., Seán Cournane Dr., Suzanne Martin Dr., Dervil Cody

Conference Papers

Holographic sensors are of interest for a range of sensing tasks because of their high sensitivity, rapid response time, broad dynamic range, lightweight characteristics, and design flexibility. The practical application of holography makes it possible to design optical sensors that are effective in the visible and near-infrared ranges. The objective of this research is to construct a holographic grating that is customised to provide quantitative data in visible light dosimetry applications. Upon exposure to visible light, the proposed holographic grating will produce a measurable change in diffraction efficiency based on the bleaching of the grating material. In the evolution of …

Rotating Scatter Mask System Optimization Study For Determining Optimal Image Recreation, Seth L. Grover

Theses and Dissertations

The Rotating Scatter Mask (RSM) system is a radiation imaging technology currently limited by the mask design and governing identification algorithm parameters. To optimize the RSM design, Dakota—an optimization software—was integrated with a ray tracing code that simulates particle interactions with the RSM detector, and with the Locally Competitive Algorithm (LCA), which reconstructs the source image based on the ray tracing code’s Detector Response Matrix (DRM). Since the original ray tracing code was developed in MATLAB, it was translated into Python to improve compatibility with both Dakota and LCA. The Python version of the ray tracing code was then integrated …

Nonlinear Physics Of Parity-Broken Fluids, Sudheesh Srivastava

Dissertations, Theses, and Capstone Projects

This thesis explores parity-breaking mechanisms, nonlinear wave phenomena, and localization transitions across different physical contexts. First, we examine modulation instability in parity-breaking systems, deriving modified nonlinear Schr¨odinger equations that reveal direction dependent instabilities. Next, we investigate wave turbulence, demonstrating numerically that parity-breaking dispersion significantly alters turbulent cascades and modifies their statistical properties. Lastly, we analyze localization in quasiperiodic tight- binding model based on polariton condensate lattice. Collectively, these studies illustrate the universal role of symmetries and nonlinear interactions in shaping macroscopic behaviors, facilitating interdisciplinary insights.

Tunable Optical Beam Focusing Using Static Water Droplets On An Electrospun Polymer Fiber, Marco Laurence M. Budlayan, Dina C. Palangyos, Jonathan N. Patricio, Susan D. Arco, Raphael A. Guerrero

Physics Faculty Publications

This work explores the use of static water microdroplets on a microfiber to vary the width of an optical beam. Varying the water droplet volume changes the beam width without replacing any optical components. A surface derived from glass deposited with polyvinyl chloride (PVC) microfibers via electrospinning was used to sustain the droplet shape on the surface. Scanning electron microscopy revealed the presence of randomly intertwined microfibers with diameters of less than 3 µm which afforded the surface a hydrophobic property. A decrease in the optical transmittance of the films and an increase in the water contact angle were also …

Abel Inversion Comparison Of Geant4 Simulation And Ozone Production Using Cavity Ringdown Spectroscopy In Nitrogen/Oxygen Mixtures In The Presence Of Alpha Radiation, Sidney John Gautrau

Dissertations

The effects of radioactive materials on atmospheric gases have been a topic of interest for years. Radioactive materials ionize the surrounding air, and subsequent reactions lead to molecules such as ozone and nitrogen oxides. The presence of these species above background levels can be used as a marker for radioactive materials which has desirable defense applications like remote detection of radioactive materials. The molecules created in the presence of radioactive materials have been quantified in literature using G-values, which is the number of molecules of a product produced per 100 eV of deposited energy. In this work, Cavity Ringdown Spectroscopy …

Molecular Insights: Advances In Single Molecule And Single Particle Detection For Analysis Of Chemical, Physical, And Biological Phenomena, James Ethan Batey

Chemistry & Biochemistry Undergraduate Honors Theses

This thesis is focused on recent advancements made in the field of chemical imaging, optical microscopy, and recent developments that have improved spatial, temporal, or spectral resolution or have made certain techniques more accessible and cost effective for their wider adoption. This thesis is organized based on the systems of interest we studied with each new technique. Although, it is important to note that many of the methods here can be used with a multitude of systems even if not explicitly mentioned. The first chapter of this thesis will discuss the current state of chemical imaging, common terminology, and important …

Gravity Wave Breaking Over Northern Utah With An Advanced Mesospheric Temperature Mapper And Sodium Lidar, Eric Davis

All Graduate Reports and Creative Projects, Fall 2023 to Present

Considerable progress has been made in recent decades in the understanding of gravity wave (GW) dynamics. However, there remain important aspects and effects that are poorly understood. In particular, the coupling and deposition of their energy and momentum into the mesosphere lower thermosphere (MLT) region and the interaction and instability dynamics that are directly associated with GW breaking. Using an Advanced Mesosphere Temperature Mapper (AMTM) several strong wave breaking events were observed in the summer of 2015 at USU’s BLO research station. These events have exhibited high momentum fluxes and associated strong wave breaking, prompting detailed data analyses. Rossby waves, …

Effects Of Group Delay Dispersion In Silica Glass On Non-Gaussian Laser Pulses, Lars Pedersen

Honors Program: Senior Projects (Public)

We present an analysis of how the group delay dispersion in silica glass affects the envelope of non-Gaussian laser pulses. In particular, we examine femtosecond pulses in the ultraviolet regime with cosine squared and symmetric exponential envelope shapes. For both envelope shapes, our results show a linear or semi-linear dependence of both the maximum electric field strength and duration on the group delay dispersion when the pulse passes through the silica glass medium with a thickness between 1 μm and 10 μm. This computational analysis is done using a fast Fourier transform method.

Impact Of Shear Flow On Marine Biofilms Using Hyperspectral Imaging, Shantanu Mahesh Kore

All Theses

Various microbial communities in marine biofilms cause biofouling on submerged surfaces, posing challenges to marine industries. Despite their ecological and economic importance, biofilms' biomechanical and biochemical responses to hydrodynamic shear stress are insufficiently understood, particularly in dynamic flow conditions. To fill this gap, our study uses an innovative fiber-optic hyperspectral imaging (HSI) system and a supercontinuum laser source to examine marine biofilms' structure, composition, and detachment behavior at different shear stress levels.

To detect spectral and spatial heterogeneity in live biofilms without labeling, we created a custom imaging pipeline that captures reflectance spectra in the 600-850 nm range, targeting microbial …

Thin-Film Optical Filters For Selective Transmission And Black-Body Reflection In Pyroelectric Energy Systems., Cedric Cruz Silva

Electronic Theses and Dissertations

Essential to pyroelectric energy systems is the ability for a pyroelectric material to achieve high temperatures rapidly. In pursuit of augmenting this process, several thin-film optical filters were designed for transmitting laser excitation in the near-infrared region, while simultaneously reflecting black-body radiation for pyroelectric materials. Designs include a classical Fabry-Perot structure with gold and tantalum pentoxide, an induced transmittance filter with silica, hafnia, and gold, and an indium-tin-oxide filter with silica, alumina, and ITO. Performance varies depending on the design. The Fabry-Perot filter experimentally showed a maximum transmittance of 42% at 1.04 μm and an infrared reflectance of 98%. The …

Growth, Cladding, And Characterization Of Single Crystal Optical Fiber: The Next Evolution In Directed Energy Systems, Allen Benton

All Dissertations

High-power fiber lasers are steadily increasing in maximum power and rapidly approaching theoretical maximum power output from a single fiber aperture. The low thermal conductivity of silica fibers is an inherent limitation to the dissipation of heat from the fiber core, and the buildup of heat within the laser gain media is the principal driver of transverse mode instability within fiber systems. This limitation necessitates the exploration of alternate fiber host materials. Due to their high thermal conductivity, excellent transmission range, ability to host most of the optically active rare earth ions, and success as bulk laser materials, single-crystalline YAG …

A System And Method For Measuring Spatially Varying Surface Appearances With A Study Of Feathers, Jessica Baron-Lis

All Dissertations

Real-world materials, particularly biological structures such as feathers exhibit complex appearances that vary spatially across their surfaces. The field of computer graphics provides a means of understanding such surfaces through material modeling which uses both analytical models and data acquired from light-surface interactions. There are many efforts within the past decade in measuring materials for graphics, but common limitations in these works include not accounting for spatially varying properties and reliance on neural networks and synthetic datasets.

Feathers from modern birds present diverse appearances due to how light interacts with their unique hierarchical microstructures. Variations in those structures lead to …

Power-Beaming: Wireless Energy Transfer Using Lasers, Spencer L. Barnett

ATU Scholars Symposium

The objective of the project is to implement a wireless energy transfer system utilizing laser technology. This system involves modulating the laser’s beam profile and spatial distribution through precise optical manipulation. The energy transmitted by the laser is captured by a photovoltaic array, commonly referred to as a solar panel, which is engineered to convert incident photons into direct current (DC) electrical power. The current challenge is to develop a reliable wireless energy transfer mechanism capable of operating over extended distances, thereby overcoming the constraints imposed by wired connections, particularly in environments where wiring is impractical, such as in space. …