Mode-Division Multiplexed Transmission In Few-Mode Fibers,
2013
University of Central Florida
Mode-Division Multiplexed Transmission In Few-Mode Fibers, Neng Bai
Electronic Theses and Dissertations
As a promising candidate to break the single-mode fiber capacity limit, mode-division multiplexing (MDM) explores the spatial dimension to increase transmission capacity in fiberoptic communication. Two linear impairments, namely loss and multimode interference, present fundamental challenges to implementing MDM. In this dissertation, techniques to resolve these two issues are presented. To de-multiplex signals subject to multimode interference in MDM, Multiple-InputMultiple-Output (MIMO) processing using adaptive frequency-domain equalization (FDE) is proposed and investigated. Both simulations and experiments validate that FDE can reduce the algorithmic complexity significantly in comparison with the conventional time-domain equalization (TDE) while achieving similar performance as TDE. To further …
Development Of Thulium Fiber Lasers For High Average Power And High Peak Power Operation,
2013
University of Central Florida
Development Of Thulium Fiber Lasers For High Average Power And High Peak Power Operation, Robert Sims
Electronic Theses and Dissertations
High power thulium fiber lasers are useful for a number of applications in both continuous-wave and pulsed operating regimes. The use of thulium as a dopant has recently gained interest due to its large bandwidth, possibility of high efficiency, possibility of high power and long wavelength ~1.8 – 2.1 μm. The longer emission wavelength of Tm-doped fiber lasers compared to Yb- and/or Er-doped fiber lasers creates the possibility for higher peak power operation due to the larger nonlinear thresholds and reduced nonlinear phase accumulation. One primary interest in Tm-doped fiber lasers has been to scale to high average powers; however, …
Active Optimal Control Strategies For Increasing The Efficiency Of Photovoltaic Cells,
2013
Univesrity of Kentucky
Active Optimal Control Strategies For Increasing The Efficiency Of Photovoltaic Cells, Sharif Aljoaba
Theses and Dissertations--Electrical and Computer Engineering
Energy consumption has increased drastically during the last century. Currently, the worldwide energy consumption is about 17.4 TW and is predicted to reach 25 TW by 2035. Solar energy has emerged as one of the potential renewable energy sources. Since its first physical recognition in 1887 by Adams and Day till nowadays, research in solar energy is continuously developing. This has lead to many achievements and milestones that introduced it as one of the most reliable and sustainable energy sources. Recently, the International Energy Agency declared that solar energy is predicted to be one of the major electricity production energy …
Absorptive And Refractive Optical Nonlinearities In Organic Molecules And Semiconductors,
2013
University of Central Florida
Absorptive And Refractive Optical Nonlinearities In Organic Molecules And Semiconductors, Davorin Peceli
Electronic Theses and Dissertations
The main purpose of this dissertation to investigate photophysical properties, third order nonlinearity and free carrier absorption and refraction in organic materials and semiconductors. Special emphasis of this dissertation is on characterization techniques of molecules with enhanced intersystem crossing rate and study of different approaches of increasing triplet quantum yield in organic molecules. Both linear and nonlinear characterization methods are described. Linear spectroscopic characterization includes absorption, fluorescence, quantum yield, anisotropy, and singletoxygen generation measurements. Nonlinear characterization, performed by picosecond and femtosecond laser systems (single and double pump-probe and Z-scan measurements), includes measurements of the triplet quantum yields, excited-state absorption, two-photon …
Non-Degenerate Two Photon Gain In Bulk Gallium Arsenide,
2013
University of Central Florida
Non-Degenerate Two Photon Gain In Bulk Gallium Arsenide, Brendan Turnbull
Electronic Theses and Dissertations
The purpose of this thesis is to investigate the nonlinear phenomena known as doubly-stimulated, non-degenerate two-photon emission (ND-2PE) in Gallium Arsenide (GaAs). 2PE refers to the simultaneous emission of two-photons as electrons move from the conduction band in a direct gap semiconductor to the valence band. Following the same path for describing one-photon emission (1PE) we describe 2PE as a product of the irradiance, and the negative of the loss which in this case is two-photon absorption, , the negative coming from the population inversion. We attempt to observe 2PE by using a frequency non-degenerate pump-probe experiment in which a …
Properties Of High Energy Laser Light Transmission Through Large Core Optical Cables,
2013
University of Central Florida
Properties Of High Energy Laser Light Transmission Through Large Core Optical Cables, Christopher Kennedy
Electronic Theses and Dissertations
Laser induced damage is of interest in studying the transmission of large amounts of optical energy through step-index, large core multimode fibers. Optical fibers often have to be routed around objects when laser light is being transmitted between two locations which require the fiber to bend into a curve. Depending on how tight the bend is, this can result in transmission losses or even catastrophic damage when the energy density of the laser pulse exceeds the damage threshold of silica glass. The purpose of this study is to: Establish a minimum bend radius that would allow high energy (GW/cm2 ) …
Beam Deflection,
2013
University of Central Florida
Beam Deflection, Matthias Münnich,
Electronic Theses and Dissertations
In order to fully understand the third order nonlinear optical response of materials under high irradiance excitation it is necessary to study the temporal and polarization dependence of nonlinear refraction and absorption. There are several existing approaches such as Z-scan and pump-probe techniques to determine those responses. As part of this work, these approaches will be briefly outlined before presenting beam deflection, applied from photothermal beam deflection, as an alternative experimental technique to determine the nonlinear refraction with its temporal and polarization dynamics. This technique measures the angle of the probe beam deflected via the index gradient of the material …
Wavelength Scale Resonant Structures For Integrated Photonic Applications,
2013
University of Central Florida
Wavelength Scale Resonant Structures For Integrated Photonic Applications, Matthew Weed
Electronic Theses and Dissertations
An approach to integrated frequency-comb filtering is presented, building from a background in photonic crystal cavity design and fabrication. Previous work in the development of quantum information processing devices through integrated photonic crystals consists of photonic band gap engineering and methods of on-chip photon transfer. This work leads directly to research into coupled-resonator optical waveguides which stands as a basis for the primary line of investigation. These coupled cavity systems offer the designer slow light propagation which increases photon lifetime, reduces size limitations toward on-chip integration, and offers enhanced light-matter interaction. A unique resonant structure explained by various numerical models …
The Impact Of Growth Conditions On Cubic Znmgo Ultraviolet Sensors,
2013
University of Central Florida
The Impact Of Growth Conditions On Cubic Znmgo Ultraviolet Sensors, Ryan Boutwell
Electronic Theses and Dissertations
Cubic Zn1-xMgxO (c-Zn1-xMgxO) thin films have opened the deep ultraviolet (DUV) spectrum to exploration by oxide optoelectronic devices. These extraordinary films are readily wet-etch-able, have inversion symmetric lattices, and are made of common and safe constituents. They also host a number of new exciting experimental and theoretical challenges. Here, the relation between growth conditions of the c-Zn1-xMgxO film and performance of fabricated ultraviolet (UV) sensors is investigated. Plasma-Enhanced Molecular Beam Epitaxy was used to grow Zn1-xMgxO thin films and formation conditions were explored by varying the growth temperature, Mg source flux, oxygen flow rate, and radio-frequency (RF) power coupled into …
Development Of Laser Spectroscopy For Elemental And Molecular Analysis,
2013
University of Central Florida
Development Of Laser Spectroscopy For Elemental And Molecular Analysis, Yuan Liu
Electronic Theses and Dissertations
Laser-Induced Breakdown Spectroscopy (LIBS) and Raman spectroscopy are still growing analytical and sensing spectroscopic techniques. They significantly reduce the time and labor cost in analysis with simplified instrumentation, and lead to minimal or no sample damage. In this dissertation, fundamental studies to improve LIBS analytical performance were performed and its fusion with Raman into one single sensor was explored. On the fundamental side, Thomson scattering was reported for the first time to simultaneously measure the electron density and temperature of laser plasmas from a solid aluminum target at atmospheric pressure. Comparison between electron and excitation temperatures brought insights into the …
Optically Isotropic Liquid Crystals For Display And Photonic Applications,
2013
University of Central Florida
Optically Isotropic Liquid Crystals For Display And Photonic Applications, Jin Yan
Electronic Theses and Dissertations
For the past few decades, tremendous progress has been made on liquid crystal display (LCD) technologies in terms of stability, resolution, contrast ratio, and viewing angle. The remaining challenge is response time. The state-of-the-art response time of a nematic liquid crystal is a few milliseconds. Faster response time is desirable in order to reduce motion blur and to realize color sequential display using RGB LEDs, which triples the optical efficiency and resolution density. Polymer-stabilized blue phase liquid crystal (PS-BPLC) is a strong candidate for achieving fast response time because its self-assembled cubic structure greatly reduces the coherence length. The response …
Inverse Problems In Multiple Light Scattering,
2013
University of Central Florida
Inverse Problems In Multiple Light Scattering, John Broky
Electronic Theses and Dissertations
The interaction between coherent waves and material systems with complex optical properties is a complicated, deterministic process. Light that scatters from such media gives rise to random fields with intricate properties. It is common perception that the randomness of these complex fields is undesired and therefore is to be removed, usually through a process of ensemble averaging. However, random fields emerging from light matter interaction contain information about the properties of the medium and a thorough analysis of the scattered light allows solving specific inverse problems. Traditional attempts to solve these kinds of inverse problems tend to rely on statistical …
Reduced Susceptibility Of Deformation Due To Vibrational And Gravitational Effects On A Focus Variable Adaptive Lens,
2013
University of Central Florida
Reduced Susceptibility Of Deformation Due To Vibrational And Gravitational Effects On A Focus Variable Adaptive Lens, Victoriya Relina
Electronic Theses and Dissertations
Orthodox optical devices, such as lenses, mirrors, and prisms, are composed of solidstate materials, which although well studied and implemented ubiquitously are severely limited in their adaptable properties. An arguably new field of adaptive optics has emerged to further expand photonic manipulation competences of optical components. Fluid-based adaptive optical components were introduced as early as 1968 [1]; such components have the ability to change the shape of their interface surface, thus allowing for a variable curvature profile. The method of manipulation varies greatly, as does the range of surface deformations. A solid-state optical component is affected by system vibration variation …
Ytterbium-Doped Fiber-Seeded Thin-Disk Master Oscillator Power Amplifier Laser System,
2013
University of Central Florida
Ytterbium-Doped Fiber-Seeded Thin-Disk Master Oscillator Power Amplifier Laser System, Christina Willis-Ott
Electronic Theses and Dissertations
Lasers which operate at both high average power and energy are in demand for a wide range of applications such as materials processing, directed energy and EUV generation. Presented in this dissertation is a high-power 1 μm ytterbium-based hybrid laser system with temporally tailored pulse shaping capability and up to 62 mJ pulses, with the expectation the system can scale to higher pulse energies. This hybrid system consists of a low power fiber seed and pre-amplifier, and a solid state thin-disk regenerative amplifier. This system has been designed to generate high power temporally tailored pulses on the nanosecond time scale. …
High Energy, High Average Power, Picosecond Laser Systems To Drive Few-Cycle Opcpa,
2013
University of Central Florida
High Energy, High Average Power, Picosecond Laser Systems To Drive Few-Cycle Opcpa, Andreas Vaupel
Electronic Theses and Dissertations
The invention of chirped-pulse amplification (CPA) in 1985 led to a tremendous increase in obtainable laser pulse peak intensities. Since then, several table-top, Ti:sapphire-based CPA systems exceeding the 100 TW-level with more than 10 W average power have been developed and several systems are now commercially available. Over the last decade, the complementary technology of optical parametric chirped-pulse amplification (OPCPA) has improved in its performance to a competitive level. OPCPA allows direct amplification of an almost-octave spanning bandwidth supporting few-cycle pulse durations at center wavelengths ranging from the visible to the mid-IR. The current record in peak power from a …
Pulsed Tm-Fiber Laser For Mid-Ir Generation,
2013
University of Central Florida
Pulsed Tm-Fiber Laser For Mid-Ir Generation, Pankaj Kadwani
Electronic Theses and Dissertations
The thulium fiber laser has gained interest due to its long emission wavelength, large bandwidth (~1.8 – 2.1 µm), high efficiencies (~60 %), and high output power levels both in cw as well as pulsed regimes. Applications like remote sensing, machining, medical tissue ablation, and mid-infrared generation benefit from high peak power thulium laser sources. Pulsed thulium fiber laser systems are advancing rapidly towards higher peak power levels and are becoming the preferred sources for these applications. This dissertation work describes the development of novel nanosecond pulsed thulium fiber laser systems with record high peak power levels targeting mid-infrared generation. …
Magneto-Photonic Crystals For Optical Sensing Applications,
2013
Michigan Technological University
Magneto-Photonic Crystals For Optical Sensing Applications, Neluka Dissanayake
Dissertations, Master's Theses and Master's Reports - Open
Among the optical structures investigated for optical sensing purpose, a significant amount of research has been conducted on photonic crystal based sensors. A particular advantage of photonic crystal based sensors is that they show superior sensitivity for ultra-small volume sensing. In this study we investigate polarization changes in response to the changes in the cover index of magneto-optic active photonic band gap structures. One-dimensional photonic-band gap structures fabricated on iron garnet materials yield large polarization rotations at the band gap edges. The enhanced polarization effects serve as an excellent tool for chemical sensing showing high degree of sensitivity for photonic …
Investigation Of Colored Dissolved Organic Matter (Cdom) Optical Properties, Nutrients, And Salinity In Coastal Florida: Springshed To Estuaries,
2013
University of South Florida
Investigation Of Colored Dissolved Organic Matter (Cdom) Optical Properties, Nutrients, And Salinity In Coastal Florida: Springshed To Estuaries, Ana Rosa Arellano
USF Tampa Graduate Theses and Dissertations
Optical parameters measured via absorption spectroscopy and high-resolution fluorescence spectroscopy were used to characterize dissolved organic matter (DOM) in the springshed of Kings Bay, a spring-fed estuary located on Florida's Springs Coast. Over the past 40 years, springs supplying groundwater to Kings Bay have shown an increase in nitrate concentration. The overall goal of this project was to fingerprint wells and spring sites with elevated nitrogen concentrations using CDOM optical properties and establish relationships between nutrient and optical parameters. Samples were obtained from various sites: springs, Kings Bay surface (KBS), wells, coastal waters in and at the mouth of Crystal …
Investigation Of Optical Dipole Traps For Trapping Neutral Atoms For Quantum Computing,
2012
California Polytechnic State University - San Luis Obispo
Investigation Of Optical Dipole Traps For Trapping Neutral Atoms For Quantum Computing, Danielle May
Physics
No abstract provided.
Logistic Curves, Extraction Costs And Peak Oil,
2012
University of Dayton
Logistic Curves, Extraction Costs And Peak Oil, Robert J. Brecha
Physics Faculty Publications
Debates about the possibility of a near-term maximum in world oil production have become increasingly prominent over the past decade, with the focus often being on the quantification of geologically available and technologically recoverable amounts of oil in the ground. Economically, the important parameter is not a physical limit to resources in the ground, but whether market price signals and costs of extraction will indicate the efficiency of extracting conventional or nonconventional resources as opposed to making substitutions over time for other fuels and technologies. We present a hybrid approach to the peak-oil question with two models in which the …
