Optics Commons^™

Experimental Investigation Of All-Optical Production Of Metastable Krypton, Joshua Carl Frechem

Physics Theses & Dissertations

Metastable production of noble gases requires significant energy due to their filled valence shells. These transitions from the ground state are in the vacuum ultraviolet and extreme ultraviolet, which are relatively inaccessible to lasers. This necessitates the use of either electron/ion bombardment via inefficient glow discharges or the use of high-power lasers and nonlinear processes. The all-optical production efficiency using these high-power lasers promises to be orders of magnitude higher than glow discharges, but far more costly. This work looks to improve all-optical production of metastable krypton (Kr*) through the use of a commercially available vacuum ultraviolet lamp with a …

Porous Silicon Photonics For Label-Free Interferometric Biosensing And Flat Optics, Tahmid Hassan Talukdar

All Dissertations

This dissertation uses porous silicon as a material platform to explore novel optical effects in three domains: (i) It studies dispersion engineering in integrated waveguides to achieve high performance group index sensing. With proper design parameters, the sensor waveguides can theoretically achieve 6 times larger group index shift compared to the actual bulk effective refractive index shift. We demonstrate the guided mode confinement factor to be a key parameter in design and implementation of these waveguides. (ii) It explores multicolor laser illumination to experimentally demonstrate perceptually enhanced colorimetric sensing, overcoming the limitations faced by many contemporary colorimetric sensors. Our technique …

Automation Of The Transition Identification Procedure For Trapping Rubidium Atoms In A Magneto-Optical Trap, Michael P. Fletcher

Physics

The words “quantum computer” often conjure images of science fiction and unrealistic technology from an impossible future. Some may even believe that they aren’t real or are only theoretical. The truth is that quantum computers are real, tangible systems with real life uses and rooted in credible scientific research. Today, many groups of scientists collaborate on research into better ways of implementing and improving quantum computing techniques. This paper will be addressing the systems required and phenomena used to achieve neutral atom trapping for quantum computation. This thesis will outline the physical phenomena involved with the frequency tuning process for …

Optimization Of Modular, Long-Range, Ultra-Fast Optical Tweezers With Fluorescence Capabilities For Single-Molecule And Single-Cell Based Biophysical Measurements, Subash C. Godar

All Dissertations

An Optical tweezer is a tightly focused laser beam that applies and senses precise and localized optical force to a dielectric microsphere and offers a unique and effective tool for manipulating the single cell or cell components, including nucleotides and dynein motor proteins. Here, I used highly stabilized optomechanical components and ultra-sensitive detection modules to significantly improve the measurement capabilities over a wide range of temporal and spatial scales. I combined the optical tweezer-based force spectroscopy technique with fluorescence microscopy to develop an integrated high-resolution force-fluorescence system capable of measuring displacements at sub-nanometer, forces at sub-piconewton over a temporal range …

Design And Characterization Of Frequency Tripling Mirrors, Amir Khabbazi Oskouei

Optical Science and Engineering ETDs

Aperiodic stacks of dielectric low- and high-index films can be designed to enhance third-harmonic generation (THG) in reflection of near infrared laser pulses using computer optimization. Numerical and analytical results suggest that the TH energy increases rapidly with increasing number of films and the ratio of the high and low index.

Our optical matrix based THG model that takes into account the full pulse bandwidth predicts conversion efficiencies of about 7% for transform-limited Gaussian pulse bandwidths of 16 nm for mirrors with 45 layers, which exceed those expected from periodic designs. Stability against film thickness fluctuations expected from the deposition …

3d Flow Field Measurements Outside Nanopores, Jeffrey Mc Hugh, Alice L. Thorneywork, Kurt Andresen, Ulrich F. Keyser

Physics and Astronomy Faculty Publications

We demonstrate a non-stereoscopic, video-based particle tracking system with optical tweezers to study fluid flow in 3D in the vicinity of glass nanopores. In particular, we used the quadrant interpolation algorithm to extend our video-based particle tracking to displacements out of the trapping plane of the tweezers. This permitted the study of flow from nanopores oriented at an angle to the trapping plane, enabling the mounting of nanopores on a micromanipulator with which it was then possible to automate the mapping procedure. Mapping of the voltage driven flow in 3D volumes outside nanopores revealed polarity dependent flow fields. This is …

Annual Faculty Research Symposium 2022, Oakwood University

Proceedings

No abstract provided.

Microscopic Nuclei Classification, Segmentation, And Detection With Improved Deep Convolutional Neural Networks (Dcnn), Md Zahangir Alom, Vijayan K. Asari, Anil Parwani, Tarek M. Taha

Electrical and Computer Engineering Faculty Publications

Background Nuclei classification, segmentation, and detection from pathological images are challenging tasks due to cellular heterogeneity in the Whole Slide Images (WSI). Methods In this work, we propose advanced DCNN models for nuclei classification, segmentation, and detection tasks. The Densely Connected Neural Network (DCNN) and Densely Connected Recurrent Convolutional Network (DCRN) models are applied for the nuclei classification tasks. The Recurrent Residual U-Net (R2U-Net) and the R2UNet-based regression model named the University of Dayton Net (UD-Net) are applied for nuclei segmentation and detection tasks respectively. The experiments are conducted on publicly available datasets, including Routine Colon Cancer (RCC) classification and …

Limits Of Detection Of Mycotoxins By Laminar Flow Strips: A Review, Xinyi Zhao, Hugh Byrne, Christine M. O’Connor, James Curtin, Furong Tian

Articles

Mycotoxins are secondary metabolic products of fungi. They are poisonous, carcinogenic, and mutagenic in nature and pose a serious health threat to both humans and animals, causing severe illnesses and even death. Rapid, simple and low-cost methods of detection of mycotoxins are of immense importance and in great demand in the food and beverage industry, as well as in agriculture and environmental monitoring, and, for this purpose, lateral flow immunochromatographic strips (ICSTs) have been widely used in food safety and environmental monitoring. The literature to date describing the development of ICSTs for the detection of different types of mycotoxins using …

Advanced Communication And Sensing Protocols Using Twisted Light And Engineered Quantum Statistics, Michelle L. Lollie

LSU Doctoral Dissertations

Advanced performance of modern technology at a fundamental physical level is driving new innovations in communication, sensing capability, and information processing. Key to this improvement is the ability to harness the power of physical phenomena at the quantum mechanical level, where light and light-matter interactions produce technological advancement not realizable by classical means. Theoretical investigation into quantum computing, sensing capability beyond classical limits, and quantum information has prompted experimental work to bring state-of-the-art quantum systems to the forefront for commercial use. This dissertation contributes to the latter portion of the work. A set of preliminaries is included highlighting pertinent physical …

Towards Improved Inertial Navigation By Reducing Errors Using Deep Learning Methodology, Hua Chen, Tarek M. Taha, Vamsy P. Chodavarapu

Electrical and Computer Engineering Faculty Publications

Autonomous vehicles make use of an Inertial Navigation System (INS) as part of vehicular sensor fusion in many situations including GPS-denied environments such as dense urban places, multi-level parking structures, and areas with thick tree-coverage. The INS unit incorporates an Inertial Measurement Unit (IMU) to process the linear acceleration and angular velocity data to obtain orientation, position, and velocity information using mechanization equations. In this work, we describe a novel deep-learning-based methodology, using Convolutional Neural Networks (CNN), to reduce errors from MEMS IMU sensors. We develop a CNN-based approach that can learn from the responses of a particular inertial sensor …

Finding Signal In The Noise: High-Fidelity, Quantitative, Optical Blood Perfusion Imaging With Interference, Abdul Mohaimen Safi

USF Tampa Graduate Theses and Dissertations

For label-free, non-invasive, wide field-of-view (FOV) imaging/monitoring of blood flow, speckle-based approaches are gaining popularity. However, to obtain quantitative flow information, speckle techniques rely on the multi-exposure scheme which requires complex, bulky, and expensive instrumentation, limiting its application to preclinical studies. This dissertation directly addresses these issues. In the first part of this dissertation, we report a novel single shot synthetic multi-exposure speckle imaging (syMESI) method to synthetically produce multi-exposure images from one short single exposure speckle image using spatial binning/averaging. We demonstrate that syMESI can reimagine conventional hardware based MESI, with low-cost single exposure laser speckle imaging (LSCI) instrumentation. …

Method Of Making Hinged Self-Referencing Fabry–Pérot Cavity Sensors, Jeremiah C. Williams, Hengky Chandrahalim

AFIT Patents

A method is provided for fabricating a passive optical sensor on a tip of an optical fiber. The method includes perpendicularly cleaving a tip of an optical fiber and mounting the tip of the optical fiber in a specimen holder of a photosensitive polymer three-dimensional micromachining machine. The method includes forming a three-dimensional microscopic optical structure within the photosensitive polymer that comprises a two cavity Fabry-Perot Interferometer (FPI) having a hinged optical layer that is pivotally coupled to a suspended structure. The method includes removing an uncured portion of the photosensitive polymer using a solvent. The method includes depositing a …

Exploring Magneto-Excitons In Bulk And Mono-Layer Semiconductors Using Non-Linear Spectroscopy Techniques, Varun Mapara

USF Tampa Graduate Theses and Dissertations

The research in two-dimensional (2D) materials has evolved from ``traditional" quantum wells based on group III-V and II-VI semiconductors to atomically thin sheets of van der Waals materials such as 2D semiconducting Transition Metal Dichalcogenides (TMDs). These 2D materials remain a stimulating field that continues to introduce new challenges. From both a fundamental physics and technological perspective, magneto-optical spectroscopy has been an essential tool in this research field. TMDs, for example, pose the challenge of characterizing their spin-valley-resolved physics and deriving implications in quantum computation and information research. With the discovery of valley Zeeman effects, the spin-valley physics of TMDs …

Three Wave Mixing In Epsilon-Near-Zero Plasmonic Waveguides For Signal Regeneration, Nicholas Mirchandani, Mark C. Harrison

Engineering Faculty Articles and Research

Vast improvements in communications technology are possible if the conversion of digital information from optical to electric and back can be removed. Plasmonic devices offer one solution due to optical computing’s potential for increased bandwidth, which would enable increased throughput and enhanced security. Plasmonic devices have small footprints and interface with electronics easily, but these potential improvements are offset by the large device footprints of conventional signal regeneration schemes, since surface plasmon polaritons (SPPs) are incredibly lossy. As such, there is a need for novel regeneration schemes. The continuous, uniform, and unambiguous digital information encoding method is phase-shift-keying (PSK), so …

Formulation And Characterization Of Fast-Curing Plastic Scintillators With High-Z Loading, Theodore W. Stephens

Theses and Dissertations

Development of novel fast-curing plastic scintillators is highly advantageous due to their potential to be manufactured via 3D printing. Several formulations were developed that exhibit enhanced photon sensitivity, producing modest but discernible photopeaks at an incident gamma energy of 122 keV. The photon sensitivity is achieved via bismuth high-Z loading; however, this practice typically results in diminished light yields. Subsequent formulations, which varied the photoinitiator concentration and curing time, demonstrated successful curing with sufficient plastic hardness, reduced purple discoloration, reduced heat buildup during curing, and resulted in less cracking during the curing process, all of which were correlated with lower …

Directionally Sensitive Gamma Imaging Using Rotating Scatter Masks And Inexpensive, Scintillation Detectors, Christopher S. Charles

Theses and Dissertations

This work demonstrates the first instantiation of the FitzGerald Rotating Scatter Mask (RSM) as a proof-of-concept for two-dimensional source direction determination using a single, inexpensive, non-cooled scintillator, as well as an alternate mask design for comparison. A large RSM was additively manufactured from low-Z, acrylic like material, and rotated around the ubiquitous standard 3" x 3" NaI(Tl) or NaI(Tl)/CsI(Tl) phoswich detector, set internally to the mask. Smaller versions of the FitzGerald and alternate RSM designs were 3D printed for testing and used in conjunction with a LaBr detector to characterize the RSM system with a size and weight reduction applied. …

Utilization And Efficient Computation Of Polarization Factor Q For Fast, Accurate Brdf Modeling, Samuel D. Butler, Michael A. Marciniak

Faculty Publications

The Bidirectional Reflectance Distribution Function (BRDF) is of substantial use in remote sensing, scene generation, and computer graphics, to describe optical scatter off realistic surfaces. This paper begins by summarizing our prior work in relating wave optics and geometric optics models, culminating with the Modified Cook-Torrance (MCT) model. The MCT model is evaluated here against aluminum, Infragold, and silver paint at various wavelengths in the IR. In each case, the MCT model is shown to outperform a standard microfacet model. Then, this paper shows a non-trivial method of computing the primary new term, the polarization factor Q. This optimization …

Charge Transport And Spin Dynamics Of Color Centers In Diamond, Damon Daw

Dissertations, Theses, and Capstone Projects

Solid state defects in diamond are promising candidates for room temperature quantum information processors (1, 3, 5). Chief among these defects is the nitrogen vacancy center (‘NV center’ or ‘NV’). The NV has long coherence times (at 300K) and its state is easily initialized, manipulated and read out (5). However, the outstanding issue of entangling NV centers in a scalable fashion, at room temperature remains a challenge. This thesis presents experimental and theoretical work aimed at achieving this goal by developing the ‘flying qubit’ framework in (1). This method for remote entanglement utilizes a charge carrier (initialized into a definite …

Resolving The Three-Dimensional Rotational And Translational Dynamics Of Single Molecules Using Radially And Azimuthally Polarized Fluorescence, Oumeng Zhang, Weiyan Zhou, Jin Lu, Tingting Wu, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

We report a radially and azimuthally polarized (raPol) microscope for high detection and estimation performance in single-molecule orientation-localization microscopy (SMOLM). With 5000 photons detected from Nile red (NR) transiently bound within supported lipid bilayers (SLBs), raPol SMOLM achieves 2.9 nm localization precision, 1.5° orientation precision, and 0.17 sr precision in estimating rotational wobble. Within DPPC SLBs, SMOLM imaging reveals the existence of randomly oriented binding pockets that prevent NR from freely exploring all orientations. Treating the SLBs with cholesterol-loaded methyl-β-cyclodextrin (MβCD-chol) causes NR’s orientational diffusion to be dramatically reduced, but curiously NR’s median lateral displacements drastically increase from 20.8 to …