Generation Of Generalized-Gauss Laser Beams Via A Spatial Light Modulator,
2018
Arkansas Tech University
Generation Of Generalized-Gauss Laser Beams Via A Spatial Light Modulator, Jessica P. Conry Young, Samantha Dix
Journal of the Arkansas Academy of Science
Generalized-Gauss laser beams can be described as a continuous transition between the well-known Hermite-Gauss (HG) and Laguerre-Gauss (LG) laser beams. A spatial light modulator (SLM) was made by removing the liquid crystal display (LCD) from an overhead projector. The homemade SLM, encoded with a computer-generated hologram, was then used to convert a fundamental Gaussian beam from a small frame Helium-Neon (HeNe) laser into several different orders of Generalized-Gauss (GG) beams. The experimentally generated GG beam profiles matched the theoretically expected profiles.
Datanet: Deep Learning Based Encrypted Network Traffic Classification In Sdn Home Gateway,
2018
Nanjing University of Posts and Telecommunications
Datanet: Deep Learning Based Encrypted Network Traffic Classification In Sdn Home Gateway, Pan Wang, Feng Ye, Xuejiao Chen, And Yi Qian
Electrical and Computer Engineering Faculty Publications
A smart home network will support various smart devices and applications, e.g., home automation devices, E-health devices, regular computing devices, and so on. Most devices in a smart home access the Internet through a home gateway (HGW). In this paper, we propose a software-defined- network (SDN)-HGW framework to better manage distributed smart home networks and support the SDN controller of the core network. The SDN controller enables efficient network quality-of-service management based on real-time traffic monitoring and resource allocation of the core network. However, it cannot provide network management in distributed smart homes. Our proposed SDN-HGW extends the control to …
Photonic Grating Coupler Designs For Optical Benching,
2018
University at Albany, State University of New York
Photonic Grating Coupler Designs For Optical Benching, Eng Wen Ong
Legacy Theses & Dissertations (2009 - 2024)
Background: Silicon Photonics has been rapidly developing as a field. The primary reason for this is its lower operating costs and faster switching rates for use in big data centres. Instead of microns-wide copper lines to transmit signals, silicon photonic chips use waveguides, usually of silicon or silicon nitride. Photonic signals bypass the issues of resistive-capacitance lag (RC-lag) and resistive-heating encountered by copper lines. Additionally, a single waveguide may transmit multiple signals along different carrier wavelengths.
Illumination Modulation For Improved Propagation-Based Phase Imaging,
2018
University at Albany, State University of New York
Illumination Modulation For Improved Propagation-Based Phase Imaging, Tonmoy Chakraborty
Legacy Theses & Dissertations (2009 - 2024)
Propagation-based phase imaging enables the quantitative reconstruction of a light beam's phase from measurements of its intensity. Because the intensity depends on the time-averaged square of the field the relationship between intensity and phase is, in general, nonlinear. The transport of intensity equation (TIE), is a linear equation relating phase and propagated intensity that arises from restricting the propagation distance to be small. However, the TIE limits the spatial frequencies that can be reliably reconstructed to those below some cutoff, which limits the accuracy of reconstruction of fine features in phase. On the other hand, the low frequency components suffer …
Fiber Optimization For Operation Beyond Transverse Mode Instability Limitations,
2018
University of Central Florida
Fiber Optimization For Operation Beyond Transverse Mode Instability Limitations, Joshua Bradford
Electronic Theses and Dissertations
Transverse Mode Instabilities (TMIs) stand as a fundamental limitation to power and brightness scaling in laser systems based upon optical fiber technologies. This work comprises experimental and theoretical investigations into fiber laser design that should minimize the effects of Stimulated Thermal Rayleigh Scattering. Theoretical discussions and simulations focus on how fiber parameters affect transverse mode coupling. These include core geometry optimization, pump geometry optimization, in addition to the effects of HOM content and losses on the TMI threshold. Experimentally, a high-power laser facility is commissioned with beam quality diagnostics to quantify the thresholds of the onset of modal interferences and …
Non-Hermitian Optics,
2018
University of Central Florida
Non-Hermitian Optics, Absar Ulhassan
Electronic Theses and Dissertations
From the viewpoint of quantum mechanics, a system must always be Hermitian since all its corresponding eigenvalues must be real. In contrast, the eigenvalues of open systems-unrestrained because of either decay or amplification-can be in general complex. Not so long ago, a certain class of non-Hermitian Hamiltonians was discovered that could have a completely real eigenvalue spectrum. This special class of Hamiltonians was found to respect the property of commutation with the parity-time (PT) operator. Translated into optics, this implies a balance between regions exhibiting gain and loss. Traditionally, loss has been perceived as a foe in optics and something …
Power Scaling Of High Power Solid State Lasers.,
2018
University of Central Florida
Power Scaling Of High Power Solid State Lasers., Bumjin Oh
Electronic Theses and Dissertations
The solid-state laser is one of the most widely used lasers in scientific research and industrial applications. This thesis describes detailed investigations of two modern architectures of high power cw solid-state lasers, a 20 W diode-pumped Yb:YAG thin disc laser and 300 W diode-pumped Nd:YAG rod laser. With the thin disc laser architecture, the signal beam must fit to the pump area on the disc defined by the multi-pass diode pump configuration. The beam propagation, beam diameter, phase and thermal effects for various cavity configurations are investigated theoretically and experimentally. In addition, the internal loss, small signal gain, and thermal …
Development Of A Tabletop Coherent Soft X-Ray Source,
2018
University of Central Florida
Development Of A Tabletop Coherent Soft X-Ray Source, Hanfu Kong
Electronic Theses and Dissertations
The goal of this thesis is to design a tabletop coherent soft X-ray source for attosecond high resolution imaging. We collect signals from gas cells with different length and lens with different focal length. A spectrometer with a grating and a CCD camera is applied to observe and measure the spectrum of the X-ray attosecond pulses. This thesis first introduces the theory background of ultrafast lasers, then mainly explains high harmonic generation, which is the key method for attosecond pulses generation, subsequently presents the experiment system and analyzes the results from the experiment, also compares different combinations of parameters of …
Liquid Crystal Phase Modulation For Beam Steering And Near-Eye Displays,
2018
University of Central Florida
Liquid Crystal Phase Modulation For Beam Steering And Near-Eye Displays, Yun-Han Lee
Electronic Theses and Dissertations
Liquid crystal spatial phase modulator plays an important role in laser beam steering, wave-front shaping and correction, optical communication, optical computation and holography. One fundamental limitation lays in the response time of liquid crystal reorientation. To achieve fast response time, polymer-network liquid crystals are therefore proposed. By incorporating polymer network in a liquid crystal host, the response time can be reduced by a factor of 100. However, the polymer network introduces hysteresis, light scattering, and high voltage. The motivation for a fast-response liquid crystal phase modulator will be discussed in the first chapter. In the second chapter, we introduce our …
Handwritten Bangla Character Recognition Using The State-Of-The-Art Deep Convolutional Neural Networks,
2018
University of Dayton
Handwritten Bangla Character Recognition Using The State-Of-The-Art Deep Convolutional Neural Networks, Md Zahangir Alom, Paheding Sidike, Mahmudul Hasan, Tarek M. Taha, Vijayan K. Asari
Electrical and Computer Engineering Faculty Publications
In spite of advances in object recognition technology, handwritten Bangla character recognition (HBCR) remains largely unsolved due to the presence of many ambiguous handwritten characters and excessively cursive Bangla handwritings. Even many advanced existing methods do not lead to satisfactory performance in practice that related to HBCR. In this paper, a set of the state-of-the-art deep convolutional neural networks (DCNNs) is discussed and their performance on the application of HBCR is systematically evaluated. The main advantage of DCNN approaches is that they can extract discriminative features from raw data and represent them with a high degree of invariance to object …
Universal Wavefront Transmission Through Disordered Media,
2018
Missouri University of Science and Technology
Universal Wavefront Transmission Through Disordered Media, Jayson Robert Summers
Masters Theses
”When electromagnetic waves propagate through random dielectric media, they scatter in a predictable, deterministic way. The process is also fully reversible. If one sends an exiting wave backward through the same material, it will converge back to its original form and location in the same amount of time it took to originally propagate through the material. Due to this predictability, a great deal of research has went into studying these scattering processes in multimode fibers, diffusers, biological tissues, and other media. Scientists have turned random scattering material into focusing lenses, image transmitters, and highly transmitting media by controlling the impinging …
Cavity-Coupled Plasmonic Systems For Enhanced Light-Matter Interactions,
2018
University of Central Florida
Cavity-Coupled Plasmonic Systems For Enhanced Light-Matter Interactions, Abraham Vazquez-Guardado
Electronic Theses and Dissertations
Light-matter interaction is a pivotal effect that involves the synergetic interplay of electromag- netic fields with fundamental particles. In this regard localized surface plasmons (LSP) arise from coherent interaction of the electromagnetic field with the collective oscillation of free electrons in confined sub-wavelength environments. Their most attractive properties are strong field en- hancements at the near field, highly inhomogeneous, peculiar temporal and spatial distributions and unique polarization properties. LSP systems also offer a unique playground for fundamental electromagnetic physics where micro-scale systemic properties can be studied in the macro-scale. These important properties and opportunities are brought up in this work …
Analysis Of The Red And Green Optical Absorption Spectrum Of Gas Phase Ammonia,
2018
Old Dominion University
Analysis Of The Red And Green Optical Absorption Spectrum Of Gas Phase Ammonia, Nikolai F. Zobov, Phillip A. Coles, Roman I. Ovsyannikov, Aleksandra A. Kyuberis, Robert J. Hargreaves, Peter F. Bernath, Jonathan Tennyson, Sergei N. Yurchenko, Oleg L. Polyansky
Chemistry & Biochemistry Faculty Publications
Room temperature NH3 absorption spectra recorded at the Kitt Peak National Solar Observatory in 1980 are analyzed. The spectra cover two regions in the visible: 15,200 - 15,700 cm-1 and 17,950 - 18,250 cm-1. These high overtone rotation-vibration spectra are analyzed using both combination differences and variational line lists. Two variational line lists were computed using the TROVE nuclear motion program: one is based on an ab initio potential energy surface (PES) while the other used a semi-empirical PES. Ab initio dipole moment surfaces are used in both cases. 95 energy levels with J = 1 …
Light Scattering From An Atomic Gas Under Conditions Of Quantum Degeneracy,
2018
Old Dominion University
Light Scattering From An Atomic Gas Under Conditions Of Quantum Degeneracy, V. M. Porozova, L. V. Gerasimov, M. D. Havey
Physics Faculty Publications
Elastic light scattering from a macroscopic atomic sample existing in the Bose-Einstein condensate phase reveals a unique physical configuration of interacting light and matter waves. However, the joint coherent dynamics of the optical excitation induced by an incident photon is influenced by the presence of incoherent scattering channels. For a sample of sufficient length the excitation transports as a polariton wave and the propagation Green's function obeys the scattering equation which we derive. The polariton dynamics could be tracked in the outgoing channel of the scattered photon as we show via numerical solution of the scattering equation for one-dimensional geometry. …
Identification Of Streptococcus Pyogenes Using Raman Spectroscopy,
2018
Wayne State University
Identification Of Streptococcus Pyogenes Using Raman Spectroscopy, Ehsan Majidi
Wayne State University Dissertations
Despite the attention that Raman Spectroscopy has gained recently in the area of pathogen identification, the spectra analyses techniques are not well developed. In most scenarios, they rely on expert intervention to detect and assign the peaks of the spectra to specific molecular vibration. Although some investigators have used machine-learning techniques to classify pathogens, these studies are usually limited to a specific application, and the generalization of these techniques is not clear. Also, a wide range of algorithms have been developed for classification problems, however, there is less insight to applying such methods on Raman spectra. Furthermore, analyzing the Raman …
Magnetless And Topological Edge Mode-Based On-Chip Isolators And Spin-Orbit Coupling In Magneto-Optic Media,
2018
Michigan Technological University
Magnetless And Topological Edge Mode-Based On-Chip Isolators And Spin-Orbit Coupling In Magneto-Optic Media, Dolendra Karki
Dissertations, Master's Theses and Master's Reports
The rapid growth of optical communication networks requires monolithic integration of various optical components such as lasers, modulators, detectors, amplifiers. Optical feedback due to reflected light at the interfaces of several components in a photonic circuit has detrimental effects to the normal operation of laser by increasing noise, forcing laser to oscillate into different lasing modes etc. So optical isolators are crucial components to make complex optical circuits possible by preventing the feedback signal from coupling back to the lasers sources. For this purpose, an optical isolator that can reduce the feedback signal by > 30 dB and at the same …
Magneto-Optical Properties Of Thin Permalloy Films: A Study Of The Magneto-Optical Generation Of Light Carrying Angular Momentum,
2018
University of Kentucky
Magneto-Optical Properties Of Thin Permalloy Films: A Study Of The Magneto-Optical Generation Of Light Carrying Angular Momentum, Patrick D. Montgomery
Theses and Dissertations--Electrical and Computer Engineering
Magneto-optical materials such as permalloy can be used to create artificial spin- ice (ASI) lattices with antiferromagnetic ordering. Magneto-optical materials used to create diffraction lattices are known to exhibit magnetic scattering at the half- order Bragg peak while in the ground state. The significant drawbacks of studying the magneto-optical generation of OAM using x-rays are cost, time, and access to proper equipment. In this work, it is shown that the possibility of studying OAM and magneto-optical materials in the spectrum of visible light at or around 2 eV is viable. Using spectroscopic ellipsometry it is possible to detect a change …
Effects Of Light Reflection On Spatial Visualization Ability And Implications For Engineering Technology Students,
2018
Old Dominion University
Effects Of Light Reflection On Spatial Visualization Ability And Implications For Engineering Technology Students, Petros Katsioloudis, Mildred Jones
STEMPS Faculty Publications
Results from a number of studies indicate that the type of light generated by the reflection on the surface of different types of surfaces can influence the spatial visualization ability; however, research provides inconsistent results. Considering this, a quasi-experimental study was conducted to identify the existence of statistically significant effects on spatial visualization ability as measured by the Mental Cutting Test and Sectional View drawing ability due to the impacts of light reflection. In particular, the study compared three types of light reflection; mirror, specular and diffuse and whether a significant difference exists among engineering technology students. According to the …
Plasmon-Enhanced Optical Sensing By Engineering Metallic Nanostructures,
2018
West Virginia University
Plasmon-Enhanced Optical Sensing By Engineering Metallic Nanostructures, Peng Zheng
Graduate Theses, Dissertations, and Problem Reports (ETD)
The world’s booming population projected to reach 10 billion by 2050 causes enormous stresses on environmental safety, food supply, and healthcare, which in return threatens human civilizations. One of the most promising solutions lies at innovating point-of-care (POC) sensing technologies to conduct detection of environmental hazards, monitoring of food safety, and early diagnosis of diseases in a timely and accurate manner. The discovery of surface-enhanced spectroscopy in the 1970s has significantly stimulated research on light-matter interaction which gives rise to enhanced optical phenomena such as surface-enhanced Raman scattering (SERS), plasmon-enhanced fluorescence (PEF), and particularly, they have found enormous applications in …
Thin-Film Lithium Niobate Photonics For Electro-Optics, Nonlinear Optics, And Quantum Optics On Silicon,
2018
University of Central Florida
Thin-Film Lithium Niobate Photonics For Electro-Optics, Nonlinear Optics, And Quantum Optics On Silicon, Ashutosh Rao
Electronic Theses and Dissertations
Ion-sliced thin-film lithium niobate (LN) compact waveguide technology has facilitated the resurgence of integrated photonics based on lithium niobate. These thin-film LN waveguides offer over an order of magnitude improvement in optical confinement, and about two orders of magnitude reduction in waveguide bending radius, compared to conventional LN waveguides. Harnessing the improved confinement, a variety of miniaturized and efficient photonic devices are demonstrated in this work. First, two types of compact electrooptic modulators are presented – microring modulators, and Mach-Zehnder modulators. Next, two distinct approaches to nonlinear optical frequency converters are implemented – periodically poled lithium niobate, and mode shape …
