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2,316 full-text articles. Page 49 of 87.

Infrared Energy Conversion In Plasmonic Fields At Two-Dimensional Semiconductors, Gregory Thomas Forcherio 2017 University of Arkansas, Fayetteville

Infrared Energy Conversion In Plasmonic Fields At Two-Dimensional Semiconductors, Gregory Thomas Forcherio

Graduate Theses and Dissertations

Conversion of infrared energy within plasmonic fields at two-dimensional, semiconductive transition metal dichalcogenides (TMD) through plasmonic hot electron transport and nonlinear frequency mixing has important implications in next-generation optoelectronics. Drude-Lorentz theory and approximate discrete dipole (DDA) solutions to Maxwell’s equations guided metal nanoantenna design towards strong infrared localized surface plasmon resonance (LSPR). Excitation and damping dynamics of LSPR in heterostructures of noble metal nanoantennas and molybdenum- or tungsten-disulfide (MoS2; WS2) monolayers were examined by parallel synthesis of (i) DDA electrodynamic simulations and (ii) near-field electron energy loss (EELS) and far-field optical transmission UV-vis spectroscopic measurements. Susceptibility to second-order nonlinear frequency …


Characterization Of Coupled Gold Nanoparticles In A Sparsely Populated Square Lattice, Roy Truett French III 2017 University of Arkansas, Fayetteville

Characterization Of Coupled Gold Nanoparticles In A Sparsely Populated Square Lattice, Roy Truett French Iii

Graduate Theses and Dissertations

Metal nanoparticles deposited in regular arrays spaced at optical wavelengths support a resonance due to a coherent coupling between localized surface plasmon mode and lattice diffraction allowing for engineering of tunable devices for use in biological sensors, nanoantennae, and enhanced spectroscopy. Techniques such as electron beam lithography, focused ion beam lithography, nanosphere lithography, and nanoimprint lithography are used for fabrication but are limited by cost, device throughput, and small deposition. Polymer soft lithography and continuous dewetting of particles is a potentially viable alternative showing promise in all of those areas. This thesis developed the fabrication of a refined hydrophilic nanoimprinted …


Plasmon-Mediated Energy Conversion In Metal Nanoparticle-Doped Hybrid Nanomaterials, Jeremy Dunklin 2017 University of Arkansas, Fayetteville

Plasmon-Mediated Energy Conversion In Metal Nanoparticle-Doped Hybrid Nanomaterials, Jeremy Dunklin

Graduate Theses and Dissertations

Climate change and population growth demand long-term solutions for clean water and energy. Plasmon-active nanomaterials offer a promising route towards improved energetics for efficient chemical separation and light harvesting schemes. Two material platforms featuring highly absorptive plasmonic gold nanoparticles (AuNPs) are advanced herein to maximize photon conversion into thermal or electronic energy. Optical extinction, attributable to diffraction-induced internal reflection, was enhanced up to 1.5-fold in three-dimensional polymer films containing AuNPs at interparticle separations approaching the resonant wavelength. Comprehensive methods developed to characterize heat dissipation following plasmonic absorption was extended beyond conventional optical and heat transfer descriptions, where good agreement was …


Analysis Of Beam Deflection Measurements In The Presence Of Linear Absorption, Manuel R. Ferdinandus, Jennifer Reed, Kent L. Averett, F. Kenneth Hopkins, Augustine Urbas 2017 Air Force Institute of Technology

Analysis Of Beam Deflection Measurements In The Presence Of Linear Absorption, Manuel R. Ferdinandus, Jennifer Reed, Kent L. Averett, F. Kenneth Hopkins, Augustine Urbas

Faculty Publications

We develop a series of analytical approximations allowing for rapid extraction of the nonlinear parameters from beam deflection measurements. We then apply these approximations to the analysis of cadmium silicon phosphide and compare the results against previously published parameter extraction methods and find good agreement for typical experimental conditions.


Key Encryption Through Quantum Optics, Madison Durrance, Zach Galberd, Abbey Savage, Tristan Cabrera, Josh Hoffman 2017 Georgia College and State University

Key Encryption Through Quantum Optics, Madison Durrance, Zach Galberd, Abbey Savage, Tristan Cabrera, Josh Hoffman

Georgia College Student Research Events

Cryptography has been around since the dawn of human civilization to send private messages for commercial, military, and political purposes. Some of the most important ciphers are the Vigenère cipher, the enigma, and the more modern RSA. Because of the development of the internet, private encryption has also become increasingly more important. The weakest link of encryption is the key creation and key distribution. A key is needed to encrypt and decipher codes and is needed by both the user and sender. A solution to this problem is the generation of quantum key distributions. In our experiment, we are now …


Angle- Scanning Spectropolarimetry: From The Ultraviolet To The Infrared, Sahar A. Nouri 2017 University of Alabama in Huntsville

Angle- Scanning Spectropolarimetry: From The Ultraviolet To The Infrared, Sahar A. Nouri

Research Horizons Day Posters

No abstract provided.


Coherent Response Of Two Dimensional Electron Gas Probed By Two Dimensional Fourier Transform Spectroscopy, Jagannath Paul 2017 University of South Florida

Coherent Response Of Two Dimensional Electron Gas Probed By Two Dimensional Fourier Transform Spectroscopy, Jagannath Paul

USF Tampa Graduate Theses and Dissertations

Advent of ultrashort lasers made it possible to probe various scattering phenomena in materials that occur in a time scale on the order of few femtoseconds to several tens of picoseconds. Nonlinear optical spectroscopy techniques, such as pump-probe, transient four wave mixing (TFWM), etc., are very common to study the carrier dynamics in various material systems. In time domain, the transient FWM uses several ultrashort pulses separated by time delays to obtain the information of dephasing and population relaxation times, which are very important parameters that govern the carrier dynamics of materials. A recently developed multidimensional nonlinear optical spectroscopy is …


Interference Of Light In Multilayer Metasurfaces: Perfect Absorber And Antireflection Coating, Khagendra Prasad Bhattarai 2017 University of South Florida

Interference Of Light In Multilayer Metasurfaces: Perfect Absorber And Antireflection Coating, Khagendra Prasad Bhattarai

USF Tampa Graduate Theses and Dissertations

We have studied several metamaterials structures with multiple layers by explaining them theoretically and verifying experimentally. The engineered structures we have designed work either as a perfect absorber or antireflection coating. The multilayer model as we call it Three Layer Model (TLM) has been developed, which gives the total reflection and transmission as a function of reflection and transmission of individual layers. By manipulating the amplitude and phase of the reflection and the transmission of the individual layers, we can get the required functionality of the optoelectronic devices. To get zero reflection in the both perfect absorber and the antireflection …


Superpositioning High Power Lasers For Mid-Air Image Formations, Auston Viotto 2017 University of Nebraska-Lincoln

Superpositioning High Power Lasers For Mid-Air Image Formations, Auston Viotto

UCARE: Research Products

This research evaluates different methods to create voxels, 3-dimensional pixels, in air without the need for special glasses or reflections off of surfaces. Research on the advantages of superimposing or the culmination, focusing, of laser light will be conducted. The point of superpositioning/culmination will be evaluated by the brightness of the voxel due to the Rayleigh Scatter Effect. The voxel’s brightness is dependent on the laser output strength and inversely proportional to its wavelength. Once a superimposed/culminated voxel has been created in the lab the next step will be to manipulate the location of the voxel through 3-dimensional space. This …


Cavity Perturbation Technique Of 10 Ghz Cylindrical Resonator For Modeling Rf/Ir Sensor Radomes/Windows, Marvin-Ray Arida 2017 Air Force Institute of Technology

Cavity Perturbation Technique Of 10 Ghz Cylindrical Resonator For Modeling Rf/Ir Sensor Radomes/Windows, Marvin-Ray Arida

Theses and Dissertations

The dielectric properties of candidate materials for radomes or sensor windows on hypersonic vehicles, which can reach temperatures above 1,500° Celsius when traveling greater than Mach 5, are required. Although there has been recent scientific interest in the temperature dependence of the dielectric constant, little is known for temperatures near 1,500° Celsius and above. Current research utilizes large laboratory-sized furnaces to achieve these temperatures. This also requires large sample sizes, which are expensive; such expense is greatly multiplied when sweeping through hundreds of materials for research and development. In an effort to reduce these costs, this thesis modeled a 7.0 …


Using Principal Component Analysis To Improve Fallout Characterization, Derek W. Haws 2017 Air Force Institute of Technology

Using Principal Component Analysis To Improve Fallout Characterization, Derek W. Haws

Theses and Dissertations

Previous research conducted at Lawrence Livermore National Laboratory (LLNL) and the Air Force Institute of Technology (AFIT) has shown a correlation between actinide location and elemental composition in fallout from historic weapons testing. Fifty spherical fallout samples were collected from near ground zero of a surface burst weapons test. The samples were mounted in an aluminum puck then ground and polished to a hemisphere exposing the central plane. Physical morphologies of the samples ranged from clear to opaque with inclusions, voids, and/or uniform characteristics. Spectroscopy data were collected using optical microscopes and scanning electron microscopy (SEM), with radioactivity recorded through …


Synthesizing Time-Evolving Partially-Coherent Schell-Model Sources, Noah R. Van Zandt, Milo W. Hyde IV, Santasri R. Bose-Pillai, David G. Voelz, Xifeng Xiao, Steven T. Fiorino 2017 Air Force Institute of Technology

Synthesizing Time-Evolving Partially-Coherent Schell-Model Sources, Noah R. Van Zandt, Milo W. Hyde Iv, Santasri R. Bose-Pillai, David G. Voelz, Xifeng Xiao, Steven T. Fiorino

Faculty Publications

Time-evolving simulation of sources with partial spatial and temporal coherence is sometimes instructive or necessary to explain optical coherence effects. Yet, existing time-evolving synthesis techniques often require prohibitive amounts of computer memory. This paper discusses three methods for the synthesis of continuous or pulsed time-evolving sources with nearly arbitrary spatial and temporal coherence. One method greatly reduces computer memory requirements, making this type of synthesis more practical. The utility of all three methods is demonstrated via a modified form of Young's experiment. Numerical simulation and laboratory results for time-averaged irradiance are presented and compared with theory to validate the synthesis …


The Fresnel Zone Light Field Spectral Imager, Francis D. Hallada 2017 Air Force Institute of Technology

The Fresnel Zone Light Field Spectral Imager, Francis D. Hallada

Theses and Dissertations

This thesis provides a computational model and the first experimental demonstration of a Fresnel zone light field spectral imaging (FZLFSI) system. This type of system couples an axial dispersion binary diffractive optic with light field (plenoptic) camera designs providing a snapshot spectral imaging capability. A computational model of the system was developed based on wave optics methods using Fresnel propagation. It was validated experimentally and provides excellent demonstration of system capabilities. The experimentally demonstrated system was able to synthetically refocus monochromatic images across greater than a 100nm bandwidth. Furthermore, the demonstrated system was modeled to have a full range of …


Numerical Wave Optics Investigation Of Optical Scatter From Statistically Rough Surface, Ann M. Lanari 2017 Air Force Institute of Technology

Numerical Wave Optics Investigation Of Optical Scatter From Statistically Rough Surface, Ann M. Lanari

Theses and Dissertations

The Bidirectional Reflectance Distribution Function (BRDF) describes optical scatter from rough surfaces. Numerical methods can control incident wavelength and surface features. Utilizing Fourier techniques for propagation to the far field, scatter resulting from Gaussian distributed and correlated surfaces is compared to predictions of physical optics and microfacet BRDF models. For RMS surface heights greater than /2, physical optics models are shown to be consistent with resulting scatter for incident light of wavelength 3μm to 5μm and scattered angles of −2 μrad to 2 μrad illuminated at normal incidence, while microfacet models fail to predict scatter width for shorter wavelengths.


Index Of Refraction From The Near-Ultraviolet To The Near-Infrared From A Single Crystal Microwave-Assisted Cvd Diamond, Giorgio Turri, Scott Webster, Ying Chen, Benjamin Wickham, Andrew Bennett, Michael Bass 2017 Embry-Riddle Aeronautical University

Index Of Refraction From The Near-Ultraviolet To The Near-Infrared From A Single Crystal Microwave-Assisted Cvd Diamond, Giorgio Turri, Scott Webster, Ying Chen, Benjamin Wickham, Andrew Bennett, Michael Bass

Publications

The refractive index of a type IIa CVD-grown single-crystal diamond was measured by ellipsometry from the near ultraviolet to the near infrared region of the spectrum. As a consequence, a one term Sellmeier Equation with coefficents of B-1 = 4.658 and C-1 = 112.5 for the refractive index of diamond, for the wavelength range from 300 to 1650 nm, was derived that is only as accurate as the input data, +/- 0.002. The experimental results in this paper between 800 and 1650 nm are new, adding to the values available in the literature.


Slow Light In Flight Imaging, Kali Wilson, Bethany Little, Genevieve Gariepy, Robert Henderson, John C. Howell, Daniele Faccio 2017 Heriot-Watt University

Slow Light In Flight Imaging, Kali Wilson, Bethany Little, Genevieve Gariepy, Robert Henderson, John C. Howell, Daniele Faccio

Mathematics, Physics, and Computer Science Faculty Articles and Research

Slow-light media are of interest in the context of quantum computing and enhanced measurement of quantum effects, with particular emphasis on using slow light with single photons. We use light-in-flight imaging with a single-photon avalanche diode camera array to image in situ pulse propagation through a slow-light medium consisting of heated rubidium vapor. Light-in-flight imaging of slow-light propagation enables direct visualization of a series of physical effects, including simultaneous observation of spatial pulse compression and temporal pulse dispersion. Additionally, the single-photon nature of the camera allows for observation of the group velocity of single photons with measured single-photon fractional delays …


Block Matching And Wiener Filtering Approach To Optical Turbulence Mitigation And Its Application To Simulated And Real Imagery With Quantitative Error Analysis, Russell C. Hardie, Michael Armand Rucci, Barry K. Karch, Alexander J. Dapore 2017 University of Dayton

Block Matching And Wiener Filtering Approach To Optical Turbulence Mitigation And Its Application To Simulated And Real Imagery With Quantitative Error Analysis, Russell C. Hardie, Michael Armand Rucci, Barry K. Karch, Alexander J. Dapore

Electrical and Computer Engineering Faculty Publications

We present a block-matching and Wiener filtering approach to atmospheric turbulence mitigation for long-range imaging of extended scenes. We evaluate the proposed method, along with some benchmark methods, using simulated and real-image sequences. The simulated data are generated with a simulation tool developed by one of the authors. These data provide objective truth and allow for quantitative error analysis. The proposed turbulence mitigation method takes a sequence of short-exposure frames of a static scene and outputs a single restored image. A block-matching registration algorithm is used to provide geometric correction for each of the individual input frames. The registered frames …


Simulation Of Anisoplanatic Imaging Through Optical Turbulence Using Numerical Wave Propagation With New Validation Analysis, Russell C. Hardie, Jonathan D. Power, Daniel A. LeMaster, Douglas R. Droege, Szymon Gladysz, Santasri Bose-Pillai 2017 University of Dayton

Simulation Of Anisoplanatic Imaging Through Optical Turbulence Using Numerical Wave Propagation With New Validation Analysis, Russell C. Hardie, Jonathan D. Power, Daniel A. Lemaster, Douglas R. Droege, Szymon Gladysz, Santasri Bose-Pillai

Electrical and Computer Engineering Faculty Publications

We present a numerical wave propagation method for simulating imaging of an extended scene under anisoplanatic conditions. While isoplanatic simulation is relatively common, few tools are specifically designed for simulating the imaging of extended scenes under anisoplanatic conditions. We provide a complete description of the proposed simulation tool, including the wave propagation method used. Our approach computes an array of point spread functions (PSFs) for a two-dimensional grid on the object plane. The PSFs are then used in a spatially varying weighted sum operation, with an ideal image, to produce a simulated image with realistic optical turbulence degradation. The degradation …


Practical Guide To The Realization Of A Convertible Optical Trapping System, Chenglong Zhao 2017 University of Dayton

Practical Guide To The Realization Of A Convertible Optical Trapping System, Chenglong Zhao

Physics Faculty Publications

In this article, we provide a detailed guide to the construction of a convertible optical trapping system for either single-beam or counter-propagating trap. The single-beam trap maintains all the functionalities that a conventional optical tweezer has. While the counter-propagating trap allows for the trapping of particles that single-beam trap cannot handle. The counter-propagating trap can be easily switched to a single-beam trap, and vice versa. Therefore, this convertible optical trapping system allows for the trapping and manipulation of particles with a wide variety of sizes and materials.


Optical Forces Generated By Plasmonic Nanostructures, Matthew A. Moocarme 2017 CUNY Graduate Center

Optical Forces Generated By Plasmonic Nanostructures, Matthew A. Moocarme

Dissertations, Theses, and Capstone Projects

For millennia, scientists have sought to uncover the secrets of what holds the world together. Optical physicists are often at the forefront, unraveling material properties through investigations of light-matter interactions. As the field has progressed, the smallest unit at which matter can be probed and manipulated has subsequently decreased. The resulting sub-field nanophotonics- which reflects the processing of light at the nanoscale- has blossomed into a vast design space for both applied and theoretical researchers. Plasmonics, the phenomena by which the electron-density of a material oscillates in response to incident electromagnetic radiation, is a subject that has excited nanophotonics researchers …


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