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2021 Full-Text Articles 2920 Authors 366249 Downloads 53 Institutions

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2021 full-text articles. Page 1 of 57.

Chiral Light Intrinsically Couples To Extrinsic/Pseudo-Chiral Metasurfaces Made Of Tilted Gold Nanowires, Alessandro Belardini, Marco Centini, Grigore Leahu, David C. Hooper, Roberto Li Voti, Eugenio Fazio, Joseph W. Haus, Andrew Sarangan, Ventsislav K. Valev, Concita Sibilia 2017 Sapienza Università di Roma

Chiral Light Intrinsically Couples To Extrinsic/Pseudo-Chiral Metasurfaces Made Of Tilted Gold Nanowires, Alessandro Belardini, Marco Centini, Grigore Leahu, David C. Hooper, Roberto Li Voti, Eugenio Fazio, Joseph W. Haus, Andrew Sarangan, Ventsislav K. Valev, Concita Sibilia

Andrew Sarangan

Extrinsic or pseudo-chiral (meta)surfaces have an achiral structure, yet they can give rise to circular dichroism when the experiment itself becomes chiral. Although these surfaces are known to yield differences in reflected and transmitted circularly polarized light, the exact mechanism of the interaction has never been directly demonstrated. Here we present a comprehensive linear and nonlinear optical investigation of a metasurface composed of tilted gold nanowires. In the linear regime, we directly demonstrate the selective absorption of circularly polarised light depending on the orientation of the metasurface. In the nonlinear regime, we demonstrate for the first time how second ...


Chiral Light Intrinsically Couples To Extrinsic/Pseudo-Chiral Metasurfaces Made Of Tilted Gold Nanowires, Alessandro Belardini, Marco Centini, Grigore Leahu, David C. Hooper, Roberto Li Voti, Eugenio Fazio, Joseph W. Haus, Andrew Sarangan, Ventsislav K. Valev, Concita Sibilia 2017 Sapienza Università di Roma

Chiral Light Intrinsically Couples To Extrinsic/Pseudo-Chiral Metasurfaces Made Of Tilted Gold Nanowires, Alessandro Belardini, Marco Centini, Grigore Leahu, David C. Hooper, Roberto Li Voti, Eugenio Fazio, Joseph W. Haus, Andrew Sarangan, Ventsislav K. Valev, Concita Sibilia

Joseph W Haus

Extrinsic or pseudo-chiral (meta)surfaces have an achiral structure, yet they can give rise to circular dichroism when the experiment itself becomes chiral. Although these surfaces are known to yield differences in reflected and transmitted circularly polarized light, the exact mechanism of the interaction has never been directly demonstrated. Here we present a comprehensive linear and nonlinear optical investigation of a metasurface composed of tilted gold nanowires. In the linear regime, we directly demonstrate the selective absorption of circularly polarised light depending on the orientation of the metasurface. In the nonlinear regime, we demonstrate for the first time how second ...


Role Of Antenna Modes And Field Enhancement In Second Harmonic Generation From Dipole Nanoantennas, Domenico de Ceglia, Maria Antonietta Vincenti, Costantino De Angelis, Andrea Locatelli, Joseph W. Haus, Michael Scalora 2017 Charles M. Bowden Research Center

Role Of Antenna Modes And Field Enhancement In Second Harmonic Generation From Dipole Nanoantennas, Domenico De Ceglia, Maria Antonietta Vincenti, Costantino De Angelis, Andrea Locatelli, Joseph W. Haus, Michael Scalora

Joseph W Haus

We study optical second harmonic generation from metallic dipole antennas with narrow gaps. Enhancement of the fundamental-frequency field in the gap region plays a marginal role on conversion efficiency. In the symmetric configuration, i.e., with the gap located at the center of the antenna axis, reducing gap size induces a significant red-shift of the maximum conversion efficiency peak. Either enhancement or inhibition of second-harmonic emission may be observed as gap size is decreased, depending on the antenna mode excited at the harmonic frequency. The second-harmonic signal is extremely sensitive to the asymmetry introduced by gap’s displacements with respect ...


Design Of Radio-Frequency Arrays For Ultra-High Field Mri, Ian R O Connell 2017 The University of Western Ontario

Design Of Radio-Frequency Arrays For Ultra-High Field Mri, Ian R O Connell

Electronic Thesis and Dissertation Repository

Magnetic Resonance Imaging (MRI) is an indispensable, non-invasive diagnostic tool for the assessment of disease and function. As an investigational device, MRI has found routine use in both basic science research and medicine for both human and non-human subjects.

Due to the potential increase in spatial resolution, signal-to-noise ratio (SNR), and the ability to exploit novel tissue contrasts, the main magnetic field strength of human MRI scanners has steadily increased since inception. Beginning in the early 1980’s, 0.15 T human MRI scanners have steadily risen in main magnetic field strength with ultra-high field (UHF) 8 T MRI systems ...


Topography Measurements Using An Airborne Ka-Band Fmcw Interferometric Synthetic Aperture Radar, Kan Fu 2017 University of Massachusetts - Amherst

Topography Measurements Using An Airborne Ka-Band Fmcw Interferometric Synthetic Aperture Radar, Kan Fu

Doctoral Dissertations May 2014 - current

Radar interferometry at millimeter-wave frequencies has the ability of topography measurement of different types of terrain, such as water surfaces and tree canopies. A Ka-band interferometric radar was mounted on an airborne platform, and flown over the Connecticut river region in western Massachusetts near Amherst on June 11, 2012. More than 20 Gigabytes of raw data was recorded. This dissertation outline presents the results of the data processing, which includes (1) the estimation and removal of the embedded high frequency phase error in the raw data; (2) the synthetic aperture processing; (3) the interferometric processing. The digital elevation model (DEM ...


Scatterometry Of 50 Nm Half Pitch Features, ruichao zhu 2016 university of new mexico

Scatterometry Of 50 Nm Half Pitch Features, Ruichao Zhu

Optical Science and Engineering ETDs

Metrology technologies are an essential adjunct to Integrated Circuit (I.C.) Semiconductor manufacturing. Scatterometry, an optical metrology, was chosen to measure 50 nm half pitch feature structures. A bread-board scatterometry system has been assembled to provide a non-contact, non-destructive, accurate and flexible measurement. A real-time, on-line scatterometry system has also been demonstrated and proven to provide a high throughput measurement.

Three different types of samples have been measured using the scatterometry setup. The wire-grid polarizer (WGP) sample has been made by Jet and Flash Nanoimprint Lithography with ~100 nm pitch and ~50 nm wide ~200 nm tall Al gratings on ...


Effects Of Position, Orientation, And Metal Loss On Ground Penetrating Radar Signals From Structural Rebar, David J. Eisenmann, Frank J. Margetan, Chien-Ping T. Chou, Shelby Ellis 2016 Iowa State University

Effects Of Position, Orientation, And Metal Loss On Ground Penetrating Radar Signals From Structural Rebar, David J. Eisenmann, Frank J. Margetan, Chien-Ping T. Chou, Shelby Ellis

David Eisenmann

Past experimental work on a highway bridge in central Iowa [1] suggested that ground penetrating radar (GPR) signals could possibly be used to differentiate intact rebar from those having substantial metal loss due to corrosion. That study made use of the amplitudes of GPR signals reflected by rebar, as obtained using a commercial instrument operated in pulse/echo mode. Many factors can contribute to the strength of the echo seen from a given rebar, including the rebar’s length, its distance from and tilt angle relative to the antenna, and the location and size of the metal-loss region. In this ...


Vector Magneto-Optical Generalized Ellipsometry For Determining Magneto-Optical Properties Of Thin Films, Chad Briley 2016 University of Nebraska-Lincoln

Vector Magneto-Optical Generalized Ellipsometry For Determining Magneto-Optical Properties Of Thin Films, Chad Briley

Theses and Dissertations from Electrical & Computer Engineering

Modern growth techniques allow for highly complex nano scale thin films to be created. These new films possess highly anisotropic properties structurally, optically, and magnetically that are significantly different from that of their bulk counterparts and must be accurately characterized in order to optimize desired properties for applications in next generation devices. Current magnetometry techniques focus on high symmetry characterization, namely in and out of the sample plane, and therefore do not possess the capabilities to fully explore these anisotropic properties without complicated setups and multiple sample manipulations. The author describes a setup that combines generalized ellipsometry with an octu-pole ...


Photoluminescence Studies Of Amorphous Boron Carbide And Tungsten Diselenide Thin Films, David M. Allendorfer 2016 University of Nebraska - Lincoln

Photoluminescence Studies Of Amorphous Boron Carbide And Tungsten Diselenide Thin Films, David M. Allendorfer

Theses and Dissertations from Electrical & Computer Engineering

For many years scientists and engineers have been researching semi-conducting materials for use in a broad array of electronic devices. With the growing demand for faster, smaller and more efficient electronics, new materials must be characterized and their properties quantified. The focus of this thesis is to develop a system to measure photoluminescence in opto-electronic materials. Photoluminescence measurements are important because it can give researchers valuable information about a material’s band structure. This thesis begins by presenting the carrier recombination mechanisms and how they apply to photoluminescence. A system was developed to measure photoluminescence spectroscopy. This system was tested ...


A Multi-Channel 3d-Printed Bioreactor For Evaluation Of Growth And Production In The Microalga Dunaliella Sp, Cristian A. Cox 2016 University of Maine

A Multi-Channel 3d-Printed Bioreactor For Evaluation Of Growth And Production In The Microalga Dunaliella Sp, Cristian A. Cox

Electronic Theses and Dissertations

We explored the capabilities of additive manufacturing using a photo-cured jetted material 3D printer to manufacture a milli-microfluidic device with direct application in microalgae Dunaliella sp growth and intracellular compounds biosynthesis tests. A continuous microbioreactor for microalgae culture was CAD designed and successfully built in 1 hour and 49 minutes using black photopolymer cured by UV and a support material. The microreactor was made up of 2 parts including the bioreactor itself and a microchannel network for culture media fluids and microalgae. Both parts were assembled to form a single unit. Additional optical and auxiliar components were added. An external ...


Time Domain Analysis Of Terahertz Photoconductive Antennas Using High- Frequency Structure Simulator (Hfss), David Carballo 2016 University of Arkansas, Fayetteville

Time Domain Analysis Of Terahertz Photoconductive Antennas Using High- Frequency Structure Simulator (Hfss), David Carballo

Electrical Engineering Undergraduate Honors Theses

In this thesis, an in-depth guide and description on how to model and perform frequency and mainly time domain analysis of a THz photoconductive antenna using HFSS will be presented. The main purpose of this thesis is to master and document the procedures for transient domain analysis in HFSS to fill the lack of documentation about this topic. Moreover, another goal is to compare the results from HFSS with the ones from another program, COMSOL (conducted by a PhD student), in order to validate the correctness of the procedure.

From this thesis, it can be concluded that in order to ...


Development Of Breast Tissue Phantoms For Enhanced Terahertz Imaging Utilizing Microdiamond And Nano-Onion Particles, Alec Walter 2016 University of Arkansas, Fayetteville

Development Of Breast Tissue Phantoms For Enhanced Terahertz Imaging Utilizing Microdiamond And Nano-Onion Particles, Alec Walter

Electrical Engineering Undergraduate Honors Theses

This thesis presents the work performed to develop tissue phantoms and a contrast agent that will be used in future research of terahertz time-domain imaging of breast tumor margins. Since an excised breast tumor can contain healthy fibrous and fatty tissues along with invasive ductal carcinoma (IDC), three phantom materials were developed. Solid phantom materials were made by using TX151 to solidify water in order to tune the refractive index and absorption coefficient of the fibrous tissue phantom and IDC phantom to the properties of freshly excised breast tissue. Various amounts of olive oil were added to the water prior ...


Segmentation Of Pulmonary Nodules In Computed Tomography Using A Regression Neural Network Approach And Its Application To The Lung Image Database Consortium And Image Database Resource Initiative Dataset, Temesguen Messay, Russell C. Hardie, Timothy R. Tuinstra 2016 University of Dayton

Segmentation Of Pulmonary Nodules In Computed Tomography Using A Regression Neural Network Approach And Its Application To The Lung Image Database Consortium And Image Database Resource Initiative Dataset, Temesguen Messay, Russell C. Hardie, Timothy R. Tuinstra

Timothy R Tuinstra, Ph.D.

We present new pulmonary nodule segmentation algorithms for computed tomography (CT). These include a fully-automated (FA) system, a semi-automated (SA) system, and a hybrid system. Like most traditional systems, the new FA system requires only a single user-supplied cue point. On the other hand, the SA system represents a new algorithm class requiring 8 user-supplied control points. This does increase the burden on the user, but we show that the resulting system is highly robust and can handle a variety of challenging cases. The proposed hybrid system starts with the FA system. If improved segmentation results are needed, the SA ...


Rain Attenuation Effects On Signal Propagation At W/V-Band Frequencies, Nadine Daoud 2016 University of New Mexico

Rain Attenuation Effects On Signal Propagation At W/V-Band Frequencies, Nadine Daoud

Electrical and Computer Engineering ETDs

The current frequency spectrum congestion in space is begging for the exploration and utilization of a new range of frequencies. The W/V-band Terrestrial Link Experiment (WTLE) project run jointly by AFRL, NASA and the University of New Mexico, focuses on using higher frequencies for satellite communications, more precisely, at 72 GHz and 84 GHz.

In this thesis, the rain effect on the propagating signal is studied. First, instantaneous comparisons between the experiment and two different models, the ITU-R and the Siva-Mello, is presented. Second, the WTLE link was analyzed statistically over a period of approximately 10 months, and the ...


Optimal And Miniaturized Strongly Coupled Magnetic Resonant Systems, Hao Hu 2016 Florida International University

Optimal And Miniaturized Strongly Coupled Magnetic Resonant Systems, Hao Hu

FIU Electronic Theses and Dissertations

Wireless power transfer (WPT) technologies for communication and recharging devices have recently attracted significant research attention. Conventional WPT systems based either on far-field or near-field coupling cannot provide simultaneously high efficiency and long transfer range. The Strongly Coupled Magnetic Resonance (SCMR) method was introduced recently, and it offers the possibility of transferring power with high efficiency over longer distances. Previous SCMR research has only focused on how to improve its efficiency and range through different methods. However, the study of optimal and miniaturized designs has been limited. In addition, no multiband and broadband SCMR WPT systems have been developed and ...


Thermoelectric Magnetohydrodynamic Effects In Solidification Processes, Andrew Kao, Koulis Pericleous, Peter Lee, Biao Cai, Jianrong Gao 2016 University of Manchester

Thermoelectric Magnetohydrodynamic Effects In Solidification Processes, Andrew Kao, Koulis Pericleous, Peter Lee, Biao Cai, Jianrong Gao

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


Analysis Of Interference Between Electromagnetic Articulography And Electroglottograph Systems, Kelly Vonderhaar 2016 Marquette University

Analysis Of Interference Between Electromagnetic Articulography And Electroglottograph Systems, Kelly Vonderhaar

Master's Theses (2009 -)

Electromagnetic Articulography (EMA) has become an integral tool for researchers and clinicians who seek to characterize speech kinematics. The position and orientation of the articulators – which include the jaw, lips, and tongue – are recorded by attaching sensors to the articulators and tracking the movement of the sensors through an electromagnetic field. This has been used by researchers and clinicians to better understand dysarthria and synthesize speech, among other applications. Another speech tool, electroglottography (EGG), is used to analyze the movement of the vocal folds during speech production. This is achieved by measuring the time variation of the contact of the ...


Optimization Of The Bowtie Gap Geometry For A Maximum Electric Field Enhancement, Tsenguun Byambadorj 2016 Marquette University

Optimization Of The Bowtie Gap Geometry For A Maximum Electric Field Enhancement, Tsenguun Byambadorj

Master's Theses (2009 -)

Optimization of the geometry of a metallic bowtie gap at radio frequency is presented in this thesis. Since the design and fabrication of a plasmonic device (nanogap) at nanoscale is challenging, the results of this study can be used to estimate the best design parameters for nanogap structure. The geometry of the bowtie gap including gap size, tip width, metal thickness, and tip angle are investigated at macroscale to find the maximum electric field enhancement across the gap. This thesis focuses on the simulation portion of a work that consists of experimental and simulation platforms. The simulation platform is created ...


Anisoplanatic Electromagnetic Image Propagation Through Narrow Or Extended Phase Turbulence Using Altitude-Dependent Structure Parameter, Monish Ranjan Chatterjee, Ali Mohamed 2016 University of Dayton

Anisoplanatic Electromagnetic Image Propagation Through Narrow Or Extended Phase Turbulence Using Altitude-Dependent Structure Parameter, Monish Ranjan Chatterjee, Ali Mohamed

Electrical and Computer Engineering Faculty Publications

The effects of turbulence on anisoplanatic imaging are often modeled through the use of a sequence of phase screens distributed along the optical path. We implement the split-step wave algorithm to examine turbulence-corrupted images.


Negative Index In Chiral Metamaterials Under Conductive Loss And First-Order Material Dispersion Using Lorentzian, Condon And Drude Models, Monish Ranjan Chatterjee, Tarig A. Algadey 2016 University of Dayton

Negative Index In Chiral Metamaterials Under Conductive Loss And First-Order Material Dispersion Using Lorentzian, Condon And Drude Models, Monish Ranjan Chatterjee, Tarig A. Algadey

Electrical and Computer Engineering Faculty Publications

Emergence of negative index (NIM) in chiral materials with conductive loss using standard dispersive models is reported. Positive and negative phase and group indices are realized as expected for NIM behavior for sidebands with opposite polarities.


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