Design, Construction, And Stabilization Of An Adjustable Repetition Rate Frequency Comb For Precision Spectroscopy,
2023
Connecticut College
Design, Construction, And Stabilization Of An Adjustable Repetition Rate Frequency Comb For Precision Spectroscopy, Matthew Carter
Physics, Astronomy and Geophysics Honors Papers
Optical frequency combs have numerous applications across the sciences. One of the most powerful applications is in molecular spectroscopy, which takes advantage of both the coherence of lasers and combs’ inherent broad bandwidth. One well-established design is the erbium fiber comb, which is popular due to its low cost and relative ease of construction. I have modified the traditional all-fiber design by introducing an adjustable free-space section which allows for adjustments to the path length, and thus the comb’s repetition rate. This low-cost addition allows for repetition rate matching, a necessity for dual-comb spectroscopy, and active repetition rate stabilization, which …
Reflective Planar Optics With Cholesteric Liquid Crystal For Near-Eye Displays,
2023
University of Central Florida
Reflective Planar Optics With Cholesteric Liquid Crystal For Near-Eye Displays, Yannanqi Li
Electronic Theses and Dissertations, 2020-2023
Display market has undergone dramatic changes as the near eye displays (NED) are gaining increasing attention because they offer a deeper level of human-computer interaction with the advancement of electronic devices and computer sciences. The NEDs can be presented in two ways: virtual reality (VR) and augmented reality (AR). The former is completely immersive while the latter combines the digital information with the surrounding scenes. Although several VR headsets have been commercialized for consumers and AR products for prosumers because of their high cost, but there is still a long way to go to satisfy the strict requirements of human …
Integrated Frequency Combs For Applications In Optical Communications & Microwave Photonics,
2023
University of Central Florida
Integrated Frequency Combs For Applications In Optical Communications & Microwave Photonics, Chinmay Shirpurkar
Electronic Theses and Dissertations, 2020-2023
This dissertation reviews the advancements made in chip-scale optical frequency combs and their applications towards optical communications and optical to RF links. We review different chip-scale comb sources and in particular, chip-scale Kerr microresonator frequency combs. Then, we establish the theoretical background in nonlinear optics which allows the formation and stabilization of Kerr solitons in nonlinear cavities. We also discuss the concept of optical injection locking and in particular, multi-tone injection locking which precedes the idea of regenerative harmonic injection locking. We then go on to show the experimental work involved in soliton generation and characterization. We show efforts towards …
Diethoxycarbonyl-Bodipys As Heavy-Atom-Free Photosensitizers For Holographic Recording In Cellulose Acetate Photopolymer,
2023
Technological University Dublin
Diethoxycarbonyl-Bodipys As Heavy-Atom-Free Photosensitizers For Holographic Recording In Cellulose Acetate Photopolymer, Aimee Sheehan, Tatsiana Mikulchyk, Catherine S.P. De Castro, Safakath Karuthedath, Wejdan Althobaiti, Metodej Dvoracek, Sabad-E Gul, Hugh Byrne, FréDéRic Laquai, Izabela Naydenova, Mikhail Filatov
Articles
A series of new heavy-atom-free photosensitizers based on 2,6-diethoxycarbonyl-BODIPY scaffold was designed and applied for holographic recording in a photopolymerizable material. Photoinduced electron transfer between the BODIPY and meso-aryl subunits, followed by the formation of BODIPY triplet excited states via spin-orbit charge transfer intersystem crossing (SOCT-ISC) was studied by steady-state and ultrafast pump-probe transient optical spectroscopy. Highly efficient photosensitization was observed for dyads bearing pyrene and anthracene substituents, which exhibited singlet oxygen generation quantum yields () of up to 94%. Charge transfer and SOCT-ISC were observed in non-polar solvent (toluene) due to the increased electron accepting ability of the diethoxycarbonyl-BODIPY. …
Surface Reconstruction In Iron Garnets,
2023
Michigan Technological University
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 …
High-Dynamic-Range And High-Efficiency Near-Eye Display Systems,
2023
University of Central Florida
High-Dynamic-Range And High-Efficiency Near-Eye Display Systems, En-Lin Hsiang
Electronic Theses and Dissertations, 2020-2023
Near-eye display systems, which project digital information directly into the human visual system, are expected to revolutionize the interface between digital information and physical world. However, the image quality of most near-eye displays is still far inferior to that of direct-view displays. Both light engine and imaging optics of near-eye display systems play important roles to the degraded image quality. In addition, near-eye displays also suffer from a relatively low optical efficiency, which severely limits the device operation time. Such an efficiency loss originates from both light engines and projection processes. This dissertation is devoted to addressing these two critical …
Particle Swarm Optimization For High Rigidity Spectrometer,
2023
Bucknell University
Particle Swarm Optimization For High Rigidity Spectrometer, Yicheng Wang
Honors Theses
The goal of this project is to find reliable parameter settings for a multi-dimensional global optimizer to optimize the performance of a large acceptance ion optical system for the requirements of nuclear physics experiments. We develop and test the Particle Swarm Optimization (PSO), a global optimization algorithm designed for continuous multi-dimensional problems, on a large acceptance particle beam separator, the High Rigidity Spectrometer (HRS) at the Facility for Rare Isotope Beams (FRIB), which is a laboratory specializing in the production and experimental study of short-lived nuclear matter. We split the HRS into two sections, the High-Transmission Beamline (HTBL) and the …
Optical Tweezers: Exerting Force With Light,
2023
Scripps College
Optical Tweezers: Exerting Force With Light, Gabriella Seifert
Scripps Senior Theses
Photons carry momentum. When a tightly-focused beam of photons hit a particle, they transfer some of their momentum to the particle, exerting a force. Optical tweezers take advantage of this phenomenon to trap (or “tweeze”) a spherical bead just after the focus of a diverging laser beam, creating a potential well that pulls in beads. In this thesis, I predict the force exerted on trapped beads and measure the actual force using an optical tweezers setup that I built. To predict the force, I follow the path of all possible rays from a diverging beam incident on a spherical bead …
Color-Changing Reflection Hologram For Quality Assurance Of Therapeutic Ultrasound Systems,
2023
Technological University Dublin
Color-Changing Reflection Hologram For Quality Assurance Of Therapeutic Ultrasound Systems, Tatsiana Mikulchyk, John Walsh, Jacinta Browne, Izabela Naydenova, Dervil Cody
Articles
The acoustic output of clinical therapeutic ultrasound equipment requires regular quality assurance (QA) testing to ensure the safety and efficacy of the treatment and that any potentially harmful deviations from the expected output power density are detected as soon as possible. A hologram, consisting of a reflection grating fabricated in an acrylate photopolymer film, has been developed to produce an immediate, visible, and permanent change in the color of the reconstructed hologram from red to green in response to incident ultrasound energy. The influence of the therapeutic ultrasound insonation parameters (exposure time, ultrasound power density, and proximity to the point …
Fabrication And Optical Properties Of Two-Dimensional Transition Metal Dichalcogenides,
2023
Michigan Technological University
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 …
Optical Design Study Of A High-Resolution Spectrograph Utilizing Photonic Lanterns For A Large Fiber Array Telescope,
2023
University of Central Florida
Optical Design Study Of A High-Resolution Spectrograph Utilizing Photonic Lanterns For A Large Fiber Array Telescope, Richard D'Alo
Graduate Thesis and Dissertation 2023-2024
Large area fiber array telescopes are a relatively modern development in the long history of telescope design and effectively create a single large equivalent aperture by combining many smaller unit telescopes at a fraction of the cost. In this study a spectrograph optical design is demonstrated that utilizes photonic lanterns in the input fiber feed for the Large Fiber Array Spectroscopic Telescope (LFAST) design concept, where photonic lanterns provide a simplified approach to the fiber feed originally proposed for LFAST. Conservation of etendue is applied to derive the relationship between slit size and photonic lantern ratio, and classical echelle spectrograph …
Compact And High Optical Efficiency Near-Eye Displays With Liquid Crystal Flat Optics,
2023
University of Central Florida
Compact And High Optical Efficiency Near-Eye Displays With Liquid Crystal Flat Optics, Junyu Zou
Electronic Theses and Dissertations, 2020-2023
Since the concepts of augmented reality (AR) and virtual reality (VR) were introduced, they have attracted people's attention worldwide, both in the industry and research areas. As the most promising hardware architecture that can bring AR/VR into daily life, near eye displays (NEDs) have been studied and investigated heavily over the past half-century, especially the concept of "Metaverse" introduced by some top companies in recent years. However, the form factor and optical efficiency are two major bottlenecks for the current NEDs before they can become the major platform. Liquid crystal (LC) flat optics have several advantages, including compact, high diffraction …
Another Angle On Perspective,
2023
Old Dominion University
Another Angle On Perspective, John Adam
Mathematics & Statistics Faculty Publications
No abstract provided.
Review-Electrode Kinetics And Electrolyte Stability In Vanadium Flow Batteries,
2023
Technological University of the Shannon, Ireland
Review-Electrode Kinetics And Electrolyte Stability In Vanadium Flow Batteries, Andrea Bourke, Daniela Oboroceanu, Nathan Quill, Catherine Lenihan, Maria Alhajji Safi Maria Alhajji Safi, Mallory A. Miller, Robert F. Savinell, Jesse S. Wainright, Varsha Sasikumarsp, Maria Rybalchenko, Pupak Amini, Niall Dalton, Robert P. Lynch, D. Noel Buckley
Articles
Two aspects of vanadium flow batteries are reviewed: electrochemical kinetics on carbon electrodes and positive electrolyte stability. There is poor agreement between reported values of kinetic parameters; however, most authors report that kinetic rates are faster for VIV/VV than for VII/VIII. Cycling the electrode potential increases the rates of both reactions initially due to roughening but when no further roughening is observed, the VII/VIII and VIV/VV reactions are affected oppositely by the pretreatment potential. Anodic pretreatment activates the electrode for the VII/VIII reaction, and deactivates it for VIV/VV. Three states of the carbon surface are suggested: reduced and oxidized states …
Concept Connectivity: An Educational And Research Framework For Scientific Learning In Optics, Photonics, And Electronic Education,
2023
Ateneo de Manila University
Concept Connectivity: An Educational And Research Framework For Scientific Learning In Optics, Photonics, And Electronic Education, Benjamin Dingel, John Gabriel C. Rivera, Francesca De Guzman Palabrica, Clint Dominic Bennett
Physics Faculty Publications
We present a novel framework referred to as Concept Connectivity that aids in educating and engaging students by presenting the topic of the Special Theory of Relativity (STR) in a coherent and unified manner. It uses different analogue implementations of the STR coming from seemingly distinct fields of study such as (i) Optics, (ii) Photonics, and (iii) Electronics to connect not only to the concepts of the STR but to the various concepts from these different fields. In these analogue implementations, the fundamental characteristics of the different STR phenomena can be mimicked in many different ways. Concept Connectivity has two …
The Employees’ Perspective: Situational Leadership Style Flexibility And Effectiveness And Employee Performance In A Technological Organization,
2023
Walden University
The Employees’ Perspective: Situational Leadership Style Flexibility And Effectiveness And Employee Performance In A Technological Organization, Merari Cortes
Walden Dissertations and Doctoral Studies
Poor employee performance can have adverse effects on business outcomes. Business leaders are concerned with poor performance, which can minimize profitability and negatively impact business sustainability. Grounded in the Situational Leadership II® model, the purpose of this quantitative correlational study was to examine the relationship between situational leadership style flexibility, effectiveness, and employee performance as perceived by employees, controlling for employee gender, job location, and tenure. A random sample of 99 technology company employees completed the Leader Behavior Analysis II®– Other and the Employee Job Performance measurement tools. Using hierarchical multilinear regression, employee gender, job location, and tenure were entered …
Emission Spectroscopy Of Ingaas Quantum Dots Via High-Resolution Fabry-Perot Interferometer,
2023
West Virginia University
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. …
The Behavior Of Partially Coherent Twisted Space-Time Beams In Atmospheric Turbulence,
2023
Air Force Institute of Technology
The Behavior Of Partially Coherent Twisted Space-Time Beams In Atmospheric Turbulence, Milo W. Hyde Iv
Faculty Publications
We study how atmospheric turbulence affects twisted space-time beams, which are non-stationary random optical fields whose space and time dimensions are coupled with a stochastic twist. Applying the extended Huygens–Fresnel principle, we derive the mutual coherence function of a twisted space-time beam after propagating a distance z through atmospheric turbulence of arbitrary strength. We specialize the result to derive the ensemble-averaged irradiance and discuss how turbulence affects the beam’s spatial size, pulse width, and space-time twist. Lastly, we generate, in simulation, twisted space-time beam field realizations and propagate them through atmospheric phase screens to validate our analysis.
Photonic Monitoring Of Atmospheric Fauna,
2022
New Jersey Institute of Technology
Photonic Monitoring Of Atmospheric Fauna, Adrien P. Genoud
Dissertations
Insects play a quintessential role in the Earth’s ecosystems and their recent decline in abundance and diversity is alarming. Monitoring their population is paramount to understand the causes of their decline, as well as to guide and evaluate the efficiency of conservation policies. Monitoring populations of flying insects is generally done using physical traps, but this method requires long and expensive laboratory analysis where each insect must be identified by qualified personnel. Lack of reliable data on insect populations is now considered a significant issue in the field of entomology, often referred to as a “data crisis” in the field. …
Atom-Specific Probing Of Electron Dynamics In An Atomic Adsorbate By Time-Resolved X-Ray Spectroscopy,
2022
Stockholm University
Atom-Specific Probing Of Electron Dynamics In An Atomic Adsorbate By Time-Resolved X-Ray Spectroscopy, Simon Schreck, Elias Diesen, Martina Dell'angela, Chang Liu, Matthew Weston, Flavio Capotondi, Hirohito Ogasawara, Jerry Larue, Roberto Costantini, Martin Beye, Piter S. Miedema, Joakim Halldin Stenlid, Jörgen Gladh, Boyang Liu, Hsin-Yi Wang, Fivos Perakis, Filippo Cavalca, Sergey Koroidov, Peter Amann, Emanuele Pedersoli, Denys Naumenko, Ivaylo Nikolov, Lorenzo Raimondi, Frank Abild-Pedersen, Tony F. Heinz, Johannes Voss, Alan C. Luntz, Anders Nilsson
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
The electronic excitation occurring on adsorbates at ultrafast timescales from optical lasers that initiate surface chemical reactions is still an open question. Here, we report the ultrafast temporal evolution of x-ray absorption spectroscopy (XAS) and x-ray emission spectroscopy (XES) of a simple well-known adsorbate prototype system, namely carbon (C) atoms adsorbed on a nickel [Ni(100)] surface, following intense laser optical pumping at 400 nm. We observe ultrafast (∼100 fs) changes in both XAS and XES showing clear signatures of the formation of a hot electron-hole pair distribution on the adsorbate. This is followed by slower changes on a few picoseconds …
