Optics Commons^™

Synthesis And Characterization Of Carbon Quantum Dots And Gold Nanoparticles For Norovirus Biosensing Applications In Water Systems, Breanne Evans

Master's Theses

Rapid, reliable detection of viral pathogens remains a significant challenge across water-treatment and environmental monitoring systems, including drinking-water, wastewater, water reuse, and environmental surveillance applications. Waterborne viral contamination can pose substantial public-health risks, making early detection essential for protecting water quality and responding quickly to treatment failures or contamination events. Direct potable reuse (DPR) is one particularly demanding example because it requires continuous verification of treatment performance and the broader need for rapid virus monitoring extends across many water-treatment and environmental surveillance applications. Norovirus is a priority target because of its widespread occurrence in wastewater, environmental persistence, and exceptionally low …

Harnessing Wavefront Shaping Control For Sensing Applications, Pablo Jara

Miners Solving for Tomorrow Research Conference

Diffuse optical tomography (DOT) and functional near-infrared spectroscopy (fNIRS) enable deep, non-invasive sensing in biological tissue but are fundamentally limited by the photon budget - most injected light is lost to scattering before reaching the detector. Wavefront shaping (WFS) can enhance signal strength inside scattering media via interference, but the conventional diffusion-based sensitivity model breaks down under coherent illumination. We develop a microscopic theory of optical sensitivity that captures interference effects neglected by diffusion theory. We prove analytically that the microscopic and diffusive descriptions coincide under random illumination and identify WFS strategies that enhance sensitivity beyond this limit. The maximum …

Impact Of Ethanol On The Evolution Of One-Step Synthesized Gold Nanoplates And Nanostars And Their Effects On Raman Signal Enhancement, Ananda Fania, Nonni Soraya Sambudi, Kirana Yuniati Putri, Yuliati Herbani, Affi Nur Hidayah

Makara Journal of Science

Gold nanoplates and nanostars were synthesized from a gold metal salt solution (HAuCl₄) using a one-step synthesis method of ultraviolet C (UVC) light irradiation. The gold salt solution was mixed with ethanol in 6 mL with the following ratios: (1.5:4.5, 3:3, and 4.5:1.5), and subsequently irradiated with UVC light. Changes in localized surface plasmon resonance (LSPR) shifts were observed in real time at 30-min intervals for 2 h. The synthesis process produces gold nanoplates. While gold nanostars were synthesized from a solution of gold salt combined with ethanol, ascorbic acid, and AgNO₃, maintaining a consistent ratio …

Harnessing Coherent-Wave Control For Sensing Applications, Pablo Jara, Arthur Goetschy, Hui Cao, Alexey Yamilov

Physics Faculty Research & Creative Works

Imaging techniques such as functional near-infrared spectroscopy and diffuse optical tomography (DOT) achieve deep, noninvasive sensing in turbid media; however, they are constrained by the photon budget, as most of the injected light is lost to scattering before reaching the detector. Wavefront shaping (WFS) can enhance signal strength via interference at specific locations within scattering media, enhancing light-matter interactions and potentially extending the penetration depth of these techniques. Interpretation of the resulting measurements relies on knowing the optical sensitivity - the relationship between changes in the detected signals and perturbations at a specific location inside the medium; however, conventional diffusion-based …

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.

Spectral Width Of Maximum Deposition Eigenchannels In Diffusive Media, Rohin E. Mcintosh, Arthur Goetschy, Nicholas Bender, Alexey Yamilov, Chia Wei Hsu, Hasan Yllmaz, Hui Cao

Physics Faculty Research & Creative Works

The maximum deposition eigenchannel provides the largest possible power delivery to a target region inside a diffusive medium by optimizing the incident wavefront of a monochromatic beam. It originates from constructive interference of scattered waves, which is frequency sensitive. We investigate the spectral width of the maximum deposition eigenchannels over a range of target depths using numerical simulations of a 2D diffusive system. Compared to tight focusing into the system, power deposition to an extended region is more sensitive to frequency detuning. The spectral width of enhanced delivery to a large target displays a rather weak, nonmonotonic variation with target …

Anderson Transition For Light In A Three-Dimensional Random Medium, Alexey Yamilov, Hui Cao, Sergey E. Skipetrov

Physics Faculty Research & Creative Works

We study Anderson transition for light in three dimensions by performing large-scale simulations of electromagnetic wave transport in disordered ensembles of perfect-electric-conducting spatially overlapping spheres. A mobility edge that separates diffusive transport and Anderson localization is identified, revealing a sharp transition from diffusion to localization for light. Critical behavior in the vicinity of the mobility edge is well described by a single parameter scaling law. The critical exponent is found to be consistent with the value known for the Anderson transition of the orthogonal universality class. Statistical distribution of total transmission at the mobility edge is described without any fit …

Photocarrier Dynamics In Dielectric And Metal-Dielectric Nanocatalysts In Ambient And Operando Conditions, Sunil Gyawali

Graduate Theses, Dissertations, and Problem Reports (ETD)

Photocatalysis, a promising method for solar-to-chemical energy conversion, relies on sunlight to generate excited charge carriers in catalysts with sufficient lifetimes and mobilities to drive photoreactions. Thin-film semiconductors are essential for reducing charge recombination and enhancing mobility but suffer from a low surface-to-volume ratio problems, resulting in a reduced absorption coefficient and limiting solar-energy-conversion efficiency. Nanostructures address these limitations by enhancing light absorption and surface reactivity. However, efficient photocatalysis also requires that the semiconductor’s band edges align with the redox potential of the desired photoreaction, limiting light absorption to just some of the whole solar spectrum. In hybrid and composite …

Characterizing 2d Materials Using Positron Impact Induced Electron Spectroscopy And Development Of A Novel Thin Film Zno Based Piezo-Photonic Detector For Cryogenic And Mems Applications, Pratyanik Sau

2024 Fall Honors Capstone Projects - Archive

Surface analytical techniques are essential for engineering nano-detectors allowing characterization of their chemical composition, electromechanical properties, and physical structure. In the first chapter, the positron impact-induced secondary electron (PIISE) energy spectra and yield from single-layer graphene (SLG) and multi-layer graphene (MLG) grown on a polycrystalline Cu substrate have been presented. In the second chapter, an extensive catalog of Positron Induced Auger Spectra is presented to aid in the analysis of elemental composition of various materials. Additionally, in the third chapter, a novel detection scheme utilizing the piezo-pyroelectric properties of Zinc Oxide (ZnO) thin films have been demonstrated for its application …

Synthesis And Characterization Of A Zirconium (Zr) Thin Film On Si(100) Via Pulsed Laser Deposition, Zikrulloh Khuzhakulov

Masters Theses & Specialist Projects

This study investigates the synthesis and characterization of zirconium (Zr) thin films deposited on Si(100) substrates using pulsed laser deposition (PLD). The effects of two laser wavelengths (1064 nm and 532 nm), various substrate temperatures (25 °C, 300 °C, and 500 °C), and different laser fluences (0.25, 0.5, 1.0 J/cm²) on the properties of the Zr films were examined. Results indicated that smoother films were achieved with the 1064 nm wavelength, while surface roughness increased with higher fluences. Optimal crystalline films were obtained at a substrate temperature of 300 °C for both wavelengths. X-ray diffraction (XRD), scanning electron microscopy (SEM), …

Development And Application Of Magnus Expansion Based Propagators For Problems In Spectroscopy And Quantum Dynamics, Taner M. Ture

Dissertations, Theses, and Capstone Projects

Stable and accurate numerical propagators of time-evolution equations in quantum mechanics are required to capture correct dynamical behavior, especially in the long time limit. Magnus expansion (ME) provides a general way to expand the real time propagator of a time dependent Hamiltonian within the exponential such that the unitarity is satisfied at any order. Integrators are developed by truncating the ME and using explicit integration of Lagrange interpolation formulas for the time dependent Hamiltonian within each time interval. The derived approximations are studied in a numerical test and compared to other available expressions. The sixth order expression is applied to …

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 …

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 …

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 …

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 …

On The Synthesis Of Heavy Rare Earth Solid Solutions And Their Hydrides, Joshua R. Van Cleave

UNLV Theses, Dissertations, Professional Papers, and Capstones

The theoretical predictions and results from the (La,Y)Hx ternary hydride solution provided evidence toward phase stability at comparatively lower pressures, as consequence the (Yb,Lu)H_x and (Tm,Lu)H_x ternary hydrides are studied here with pressures up to 25 GPa in the diamond anvil cell. The onset of an unknown feature in the XRD pattern coincides with crystallographic plane distortions in the tetragonal lattice of ytterbium hydride at their laser-heated interface, possibly driven by a solid solution of Lu-Yb. Findings in collected Raman spectra and X-ray diffraction patterns in an Ar environment suggest potential stability of the FCC and high-temperature HCP …

Tunneling Time And Faraday/Kerr Effects In Pt-Symmetric Systems, Peng Guo, Vladimir Gasparian, Antonio Antonio Perez-Garrido, Ester Jodar Ferrandez

Research & Publications

We review the generalization of tunneling time and anomalous behaviour of Fara- day and Kerr rotation angles in parity and time (PT )-symmetric systems. Similarities of two phenomena are discussed, both exhibit a phase transition-like anomalous behaviour in a certain range of model parameters. Anomalous behaviour of tunneling time and Faraday/Kerr angles in PT -symmetric systems is caused by the motion of poles of scattering amplitudes in the en- ergy/frequency complex plane.

Dynamics Of Spin And Charge Of Color Centers In Diamond Under Cryogenic Conditions, Richard G. Monge

Dissertations, Theses, and Capstone Projects

Individual quantum systems in semiconductors are currently the most sought-after platform for applications in quantum science. Most notably, the nitrogen-vacancy (NV) center in diamond features a defect deep within the electronic bandgap, making it amenable for precise manipulation to help pave the way to perform fundamental quantum physics experimentation. The NV center also offers long coherence times and versatile spin-dependent fluorescent properties, making it an ideal candidate for a nanoscale magnetometer. Furthermore, multi-color excitation offers deterministic charge state manipulation. While ambient operation has been key to their appeal, bringing NVs to cryogenic conditions opens new opportunities for alternate forms of …

Nonlinear Processes In Room Temperature Exciton-Polaritons, Prathmesh Deshmukh

Dissertations, Theses, and Capstone Projects

Strong light-matter coupling in solid state systems is an intriguing process that allows one to exploit the advantages of both light and matter. In this context, microcavities have become essential platforms for studying the strong coupling regime, where hybrid light-matter states known as exciton-polaritons form, leading to enhanced light matter interaction, modified material properties, and novel quantum phenomena. In this thesis, we explore the phenomenology of exciton-polaritons in strained TMD microcavities, 2D perovskites, fluorescent proteins and organic dyes encompassing thermalization, polariton lasing, and the observation of nonlinear effects.

Transition metal dichalcogenides (TMDs) have emerged as a remarkable class of two- …

Super-Resolution Microscopy With Color Centers In Diamond, Forrest A. Hubert

Optical Science and Engineering ETDs

This dissertation explores the development and application of diamond color centers, specifically the silicon-vacancy (SiV) and nitrogen-vacancy (NV) centers, in super-resolution microscopy and magnetic imaging techniques. It demonstrates the potential of SiV centers as photostable fluorophores in stimulated emission depletion (STED) microscopy, with a resolution of approximately 90 nm. The research also presents a method for nanoscale magnetic microscopy using NV centers by combining charge state depletion (CSD) microscopy with optically detected magnetic resonance (ODMR) to image magnetic fields produced by 30 nm iron-oxide nanoparticles. The individual magnetic feature width reaches ~100 nm while resolving magnetic field patterns from nanoparticles …

Enhanced Acousto-Optic Properties Of Silicon Carbide Based Layered Structure, Namrata Dewan Soni

Al-Bahir

This study investigates the feasibility of using silicon carbide-based layered surface acoustic wave (SAW) devices in acousto-optic applications. The acousto-optic properties of the temperature-stable layered structure TeO3/SiC/128oY-X LiNbO3 are investigated through theoretical analysis. This analysis includes the evaluation of key parameters such as the overlap integral, figure of merit, and diffraction efficiency. The SAW propagation characteristics and field profiles required for these calculations are obtained using SAW software. Results show that the layered structure has high diffraction efficiency of nearly 96% and a promising value for the acousto-optic figure of merit, indicating potential use in low driving power acousto-optic devices. …

Effective Non-Hermiticity And Topology In Markovian Quadratic Bosonic Dynamics, Vincent Paul Flynn

Dartmouth College Ph.D Dissertations

Recently, there has been an explosion of interest in re-imagining many-body quantum phenomena beyond equilibrium. One such effort has extended the symmetry-protected topological (SPT) phase classification of non-interacting fermions to driven and dissipative settings, uncovering novel topological phenomena that are not known to exist in equilibrium which may have wide-ranging applications in quantum science. Similar physics in non-interacting bosonic systems has remained elusive. Even at equilibrium, an "effective non-Hermiticity" intrinsic to bosonic Hamiltonians poses theoretical challenges. While this non-Hermiticity has been acknowledged, its implications have not been explored in-depth. Beyond this dynamical peculiarity, major roadblocks have arisen in the search …

Surface Reconstruction In Iron Garnets, Sushree Dash

Dissertations, Master's Theses and Master's Reports

This dissertation presents the results of a study investigating the physical mechanisms underlying an unexpectedly large increase in magneto-optic efficiency observed in iron garnet. Such materials are technologically important for telecommunications due to their nonreciprocal optical action. In the past, our group had found evidence of an enhanced Faraday rotation in bismuth-substituted iron garnet films less than 50 nm thick. Subsequent investigation revealed that this enhancement could be traced to surface effects. This is significant because understanding these phenomena could be used to formulate engineering solutions for device miniaturization. In this dissertation, we present the result of a research project …

Fabrication And Optical Properties Of Two-Dimensional Transition Metal Dichalcogenides, Manpreet Boora

Dissertations, Master's Theses and Master's Reports

Two-dimensional layered materials such as graphene and transition metal dichalcogenides have gained a lot of attention because of their distinctive chemical, optical, and electronic properties. Transition metal dichalcogenides can have a tunable bandgap in the range of 1 − 3 eV (visible), which enables their applications in ultrathin field effect transistors, photovoltaics, sensors, and optoelectronic devices. They exhibit an indirect-to-direct band gap transition when thinned down from bulk to a single layer. They show strong photoluminescence, electron–photon interaction, valley pseudospin, nonlinear optical response, and lack of dangling bonds. Many exotic phenomena appear when materials are thinned to nanoscale size because …

Emission Spectroscopy Of Ingaas Quantum Dots Via High-Resolution Fabry-Perot Interferometer, Raju Bhai Kc

Graduate Theses, Dissertations, and Problem Reports (ETD)

Single photons emitted from self-assembled quantum dots have been widely studied to use as a promising qubit for quantum information processing. Therefore, it is critical to fully understand the emission spectra from the quantum dot's excitation if we want to use a single photon as a quantum bit. It is almost impossible to produce rotationally symmetric quantum dots due to various growth conditions and restrictions. So the real quantum dots do not have a perfectly symmetric structure. A broken rotational symmetry causes an asymmetric exchange interaction between electron and hole, leading to a fine structure splitting between two excited states. …

Resonant Plasmonic–Biomolecular Chiral Interactions In The Far-Ultraviolet: Enantiomeric Discrimination Of Sub-10 Nm Amino Acid Films, Tiago Ramos Leite, Lin Zschiedrich, Orhan Kizilkaya, Kevin M. Mcpeak

Faculty Publications

Resonant plasmonic–molecular chiral interactions are a promising route to enhanced biosensing. However, biomolecular optical activity primarily exists in the far-ultraviolet regime, posing significant challenges for spectral overlap with current nano-optical platforms. We demonstrate experimentally and computationally the enhanced chiral sensing of a resonant plasmonic–biomolecular system operating in the far-UV. We develop a full-wave model of biomolecular films on Al gammadion arrays using experimentally derived chirality parameters. Our calculations show that detectable enhancements in the chiroptical signals from small amounts of biomolecules are possible only when tight spectral overlap exists between the plasmonic and biomolecular chiral responses. We support this conclusion …

Topological Shadow Of Higher-Order Topological Phases And Non-Hermitian Phases Protected By Generalized Rotational Symmetry, Kai Chen

Dissertations, Theses, and Capstone Projects

Topological phenomena in condensed matter physics have been investigated intensively in the past decades since the discovery of the integer quantum Hall effect (IQHE). For the IQHE, the energy band can be characterized by its topological invariants (Chern number or TKNN invariant), which relates to the quantized Hall conductance directly. Later, this expression was recognized as the first Chern class of a U(1) principal fiber bundle on a torus, where the fibers and torus correspond respectively to the magnetic Bloch waves and the magnetic Brillouin zone. And then, the discoveries of time-reversal symmetric topological insulators in two and three dimensions …

Control Of Nonlinear Properties Of Van Der Waals Materials, Rezlind Bushati

Dissertations, Theses, and Capstone Projects

Van der Waals materials are a broad class of materials that exhibit unique optoelectronic properties. They provide a rich playground for which they can be integrated into current on-chip devices due to their nanometer-scale size, and be utilized for studying fundamental physics. Strong coupling of emitters to microcavities provides many opportunities for new exotic physics through the formation of hybrid quasi-particles exciton-polaritons. This thesis
focuses on exploring and enhancing nonlinearity of van der Waals materials through strongly coupling to microcavities. By taking advantage of the stacking order of TMDs, we show intense second-harmonic generation from bulk, centrosymmetric TMD systems. In …

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 …

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 …