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Electrical and Computer Engineering

2020

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Articles 31 - 60 of 76

Full-Text Articles in Physics

One-Dimensional Multi-Frame Blind Deconvolution Using Astronomical Data For Spatially Separable Objects, Marc R. Brown Mar 2020

One-Dimensional Multi-Frame Blind Deconvolution Using Astronomical Data For Spatially Separable Objects, Marc R. Brown

Theses and Dissertations

Blind deconvolution is used to complete missions to detect adversary assets in space and to defend the nation's assets. A new algorithm was developed to perform blind deconvolution for objects that are spatially separable using multiple frames of data. This new one-dimensional approach uses the expectation-maximization algorithm to blindly deconvolve spatially separable objects. This object separation reduces the size of the object matrix from an NxN matrix to two singular vectors of length N. With limited knowledge of the object and point spread function the one-dimensional algorithm successfully deconvolved the objects in both simulated and laboratory data.


Syllabus Ee330 Electromagnetics, Nicholas Madamopoulos Mar 2020

Syllabus Ee330 Electromagnetics, Nicholas Madamopoulos

Open Educational Resources

Concepts covered in the undergraduate electrical engineering class of electromagnetics


Infrared-Active Phonon Modes In Single-Crystal Thorium Dioxide And Uranium Dioxide, Sean Knight, Rafal Korlacki, Christina Dugan, James C. Petrosky, Alyssa Lynn Mock, Peter A. Dowben, J. Matthew Mann, Martin M. Kimani, Mathias Schubert Mar 2020

Infrared-Active Phonon Modes In Single-Crystal Thorium Dioxide And Uranium Dioxide, Sean Knight, Rafal Korlacki, Christina Dugan, James C. Petrosky, Alyssa Lynn Mock, Peter A. Dowben, J. Matthew Mann, Martin M. Kimani, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

The infrared-active phonon modes, in single-crystal samples of thorium dioxide (ThO2) and uranium dioxide (UO2), were investigated using spectroscopic ellipsometry and compared with density functional theory. Both ThO2 and UO2 are found to have one infrared-active phonon mode pair [consisting of one transverse optic (TO) and one associated longitudinal optic (LO) mode], which is responsible for the dominant features in the ellipsometric data. At room temperature, our results for the mode pair’s resonant frequencies and broadening parameters are comparable with previous reflectance spectroscopy characterizations and density functional theory predictions. For ThO2, our …


Optimizing Llrf Parameters In The Electron-Ion Collider, William M. Bjorndahl Mar 2020

Optimizing Llrf Parameters In The Electron-Ion Collider, William M. Bjorndahl

Physics

To improve particle interaction in the future Electron-Ion Collider (EIC), we investigated different feedback implementations to control the accelerating voltage and examined the power and beam phase for each instance. Using MATLAB, we studied three feedback mechanisms: Direct, One Turn, and Feedforward. Enacting feedforward yielded the best performance. To minimize the klystron power consumption, we analyzed different Low-Level Radio Frequency (LLRF) parameters such as detuning. Combining theory and simulated results, we found the optimal detuning value that minimizes klystron power consumption.


Measurement Of The 160Gd(P,N)160Tb Excitation Function From 4 18 Mev, Using A Stacked Foil Technique, Ryan K. Chapman Mar 2020

Measurement Of The 160Gd(P,N)160Tb Excitation Function From 4 18 Mev, Using A Stacked Foil Technique, Ryan K. Chapman

Theses and Dissertations

A stack of thin Gd, Ti, and Cu foils were irradiated with an 18 MeV proton beam at Lawrence-Berkeley National Laboratory's 88-Inch Cyclotron to investigate the 160Gd(p,n)160Tb nuclear reaction for nuclear forensics applications. This experiment will improve knowledge of 160Tb production rates, allowing 160Tb to be efficiently created in a foil stack consisting of other proton induced isotopes for forensics applications. A set of 15 measured cross sections between 4-18 MeV for 160Gd(p,n)160Tb were obtained using a stacked foil technique. The foil stack consisted of one stainless steel, one iron, fifteen gadolinium, …


Synthesizing General Electromagnetic Partially Coherent Sources From Random, Correlated Complex Screens, Milo W. Hyde Iv Mar 2020

Synthesizing General Electromagnetic Partially Coherent Sources From Random, Correlated Complex Screens, Milo W. Hyde Iv

Faculty Publications

We present a method to generate any genuine electromagnetic partially coherent source (PCS) from correlated, stochastic complex screens. The method described here can be directly implemented on existing spatial-light-modulator-based vector beam generators and can be used in any application which utilizes electromagnetic PCSs. Our method is based on the genuine cross-spectral density matrix criterion. Applying that criterion, we show that stochastic vector field realizations (corresponding to a desired electromagnetic PCS) can be generated by passing correlated Gaussian random numbers through “filters” with space-variant transfer functions. We include step-by-step instructions on how to generate the electromagnetic PCS field realizations. As an …


Measuring Localization Confidence For Quantifying Accuracy And Heterogeneity In Single-Molecule Super-Resolution Microscopy, Hesam Mazidi, Tianben Ding, Arye Nehorai, Matthew D. Lew Feb 2020

Measuring Localization Confidence For Quantifying Accuracy And Heterogeneity In Single-Molecule Super-Resolution Microscopy, Hesam Mazidi, Tianben Ding, Arye Nehorai, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

We present a computational method, termed Wasserstein-induced flux (WIF), to robustly quantify the accuracy of individual localizations within a single-molecule localization microscopy (SMLM) dataset without ground- truth knowledge of the sample. WIF relies on the observation that accurate localizations are stable with respect to an arbitrary computational perturbation. Inspired by optimal transport theory, we measure the stability of individual localizations and develop an efficient optimization algorithm to compute WIF. We demonstrate the advantage of WIF in accurately quantifying imaging artifacts in high-density reconstruction of a tubulin network. WIF represents an advance in quantifying systematic errors with unknown and complex distributions, …


A Computationally-Efficient Bound For The Variance Of Measuring The Orientation Of Single Molecules, Tingting Wu, Tianben Ding, Hesam Mazidi, Oumeng Zhang, Matthew D. Lew Feb 2020

A Computationally-Efficient Bound For The Variance Of Measuring The Orientation Of Single Molecules, Tingting Wu, Tianben Ding, Hesam Mazidi, Oumeng Zhang, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

Modulating the polarization of excitation light, resolving the polarization of emitted fluorescence, and point spread function (PSF) engineering have been widely leveraged for measuring the orientation of single molecules. Typically, the performance of these techniques is optimized and quantified using the Cramér-Rao bound (CRB), which describes the best possible measurement variance of an unbiased estimator. However, CRB is a local measure and requires exhaustive sampling across the measurement space to fully characterize measurement precision. We develop a global variance upper bound (VUB) for fast quantification and comparison of orientation measurement techniques. Our VUB tightly bounds the diagonal elements of the …


In-Situ Gold-Ceria Nanoparticles: Superior Optical Fluorescence Quenching Sensor For Dissolved Oxygen, Nader Shehata, Ishac Kandas, Effat Samir Feb 2020

In-Situ Gold-Ceria Nanoparticles: Superior Optical Fluorescence Quenching Sensor For Dissolved Oxygen, Nader Shehata, Ishac Kandas, Effat Samir

Electrical & Computer Engineering Faculty Publications

Cerium oxide (ceria) nanoparticles (NPs) have been proved to be an efficient optical fluorescent material through generating visible emission (~530 nm) under violet excitation. This feature allowed ceria NPs to be used as an optical sensor via the fluorescence quenching Technique. In this paper, the impact of in-situ embedded gold nanoparticles (Au NPs) inside ceria nanoparticles was studied. Then, gold–ceria NPs were used for sensing dissolved oxygen (DO) in aqueous media. It was observed that both fluorescence intensity and lifetime were changed due to increased concentration of DO. Added gold was found to enhance the sensitivity of ceria to DO …


Dual-Axis Solar Tracker, Bryan Kennedy Jan 2020

Dual-Axis Solar Tracker, Bryan Kennedy

All Undergraduate Projects

Renewable energies, and fuels that are not fossil fuel-based, are one of the prolific topics of debate in modern society. With climate change now becoming a primary focus for scientists and innovators of today, one of the areas for the largest amount of potential and growth is that of the capturing and utilization of Solar Energy. This method involves using a mechanical system to track the progression of the sun as it traverses the sky throughout the day. A dual-axis solar tracker such as the one designed and built for this project, can follow the sun both azimuthally and in …


Resource Efficient Design Of Quantum Circuits For Cryptanalysis And Scientific Computing Applications, Edgard Munoz-Coreas Jan 2020

Resource Efficient Design Of Quantum Circuits For Cryptanalysis And Scientific Computing Applications, Edgard Munoz-Coreas

Theses and Dissertations--Electrical and Computer Engineering

Quantum computers offer the potential to extend our abilities to tackle computational problems in fields such as number theory, encryption, search and scientific computation. Up to a superpolynomial speedup has been reported for quantum algorithms in these areas. Motivated by the promise of faster computations, the development of quantum machines has caught the attention of both academics and industry researchers. Quantum machines are now at sizes where implementations of quantum algorithms or their components are now becoming possible. In order to implement quantum algorithms on quantum machines, resource efficient circuits and functional blocks must be designed. In this work, we …


Improved Contacts And Device Performance In Mos2 Transistors Using 2d Semiconductor Interlayers, Kraig Andrews Jan 2020

Improved Contacts And Device Performance In Mos2 Transistors Using 2d Semiconductor Interlayers, Kraig Andrews

Wayne State University Dissertations

The rapid growth of modern electronics industry over the past half-century has been sustained by the continued miniaturization of silicon-based electronics. However, as fundamental limits approach, there is a need to search for viable alternative materials for next-generation electronics in the post-silicon era. Two-dimensional (2D) semiconductors such as transition metal dichalcogenides (TMDs) have attracted much attention due to their atomic thickness, absence of dangling bonds and moderately high carrier mobility. However, achieving low-resistance contacts has been major impediment in developing high-performance field-effect transistors (FETs) based on 2D semiconductors. A substantial Schottky barrier (SB) is often present at the metal/2D-semicondcutor interface, …


Simultaneous Measurement Of Displacement And Temperature Based On Two Cascaded Balloon-Like Bent Fibre Structures, Ke Tian, Ruoning Wang, Meng Zhang, Xiafan Wang, Xin Wang, Guoyong Jin, Elfed Lewis, Gerald Farrell, Pengfei Wang Jan 2020

Simultaneous Measurement Of Displacement And Temperature Based On Two Cascaded Balloon-Like Bent Fibre Structures, Ke Tian, Ruoning Wang, Meng Zhang, Xiafan Wang, Xin Wang, Guoyong Jin, Elfed Lewis, Gerald Farrell, Pengfei Wang

Articles

A low-cost optical fibre sensor based on two cascaded balloon-like bent fibre (BBF) structures for simultaneous displacement and temperature measurement is reported. The sensor is fabricated by cascading two balloon-like bent single-mode fibres (SMFs) which with different bending radii, generating two separate interference dips within a limited wavelength range. The wavelength of the two interference dips exhibits different responses to external displacement and temperature variations, hence simultaneous measurement of displacement and temperature is realized. Experimental results show that the proposed optical fibre sensor achieves a displacement sensitivity of −318.8 pm/μm and a temperature sensitivity of 47.4 pm/°C. Taking advantage of …


Microfluidic Flow Direction And Rate Vector Sensor Based On A Partially Gold-Coated Tfbg, Changyu Shen, Dejun Liu, Xiaokang Lian, Tingting Lang, Chunliu Zhao, Yuliya Semenova, Jacques Albert Jan 2020

Microfluidic Flow Direction And Rate Vector Sensor Based On A Partially Gold-Coated Tfbg, Changyu Shen, Dejun Liu, Xiaokang Lian, Tingting Lang, Chunliu Zhao, Yuliya Semenova, Jacques Albert

Articles

In microfluidic chips applications, the monitoring of the rate and the direction of a microfluidic flow is very important. Here, we demonstrate a liquid flow rate and a direction sensor using a partially gold-coated tilted fiber Bragg grating (TFBG) as the sensing element. Wavelength shifts and amplitude changes of the TFBG transmission resonances in the near infrared reveal the direction of the liquid flowing along the fiber axis in the vicinity of the TFBG due to a nanoscale gold layer over part of the TFBG. For a device length of 10 mm (and a diameter of 125 µm for easy …


Nis2 As A Broadband Saturable Absorber For Ultrafast Pulse Lasers, Pengfei Wang, Han Zhang, Yu Yin, Qiuyun Ouyang, Yujin Chen, Elfed Lewis, Gerald Farrell, Masaki Tokurakawa, Sulaiman Wadi Harun, Cong Wang, Shi Li Jan 2020

Nis2 As A Broadband Saturable Absorber For Ultrafast Pulse Lasers, Pengfei Wang, Han Zhang, Yu Yin, Qiuyun Ouyang, Yujin Chen, Elfed Lewis, Gerald Farrell, Masaki Tokurakawa, Sulaiman Wadi Harun, Cong Wang, Shi Li

Articles

Nickel disulfide (NiS2) has recently been found to possess strong nonlinear saturable absorption properties. This feature is highly attractive for nonlinear photonics applications. Ultrafast pulse generation is successfully demonstrated in this article for both Ytterbium- and Erbium-doped fibre lasers using micro-fibre deposited nickel disulfide (NiS2) as a saturable absorber (SA). The fabricated SA device has a modulation depth of 23% at 1.06 μm and 30.8% at 1.55 μm. Stable dissipative soliton operation was achieved at 1064.5 nm with a pulse duration of 11.7 ps and another stable conventional soliton pulse train was also obtained at 1560.2 nm with a pulse …


Intense Mid-Infrared Emission At 3.9 Μm In Ho3+-Doped Zbya Glasses For Potential Use As A Fiber Laser, Haiyan Zhao, Ruicong Wang, Xin Wang, Shijie Jia, Yaxian Fan, Elfed Lewis, Gerald Farrell, Shunbin Wang, Pengfei Wang Jan 2020

Intense Mid-Infrared Emission At 3.9 Μm In Ho3+-Doped Zbya Glasses For Potential Use As A Fiber Laser, Haiyan Zhao, Ruicong Wang, Xin Wang, Shijie Jia, Yaxian Fan, Elfed Lewis, Gerald Farrell, Shunbin Wang, Pengfei Wang

Articles

Intense mid-infrared emission at 3.9 µm in Ho3+-doped ZBYA glasses with direct upper laser level (Ho3+ : 5 I5) pumping at a wavelength of 888 nm is reported for the first time, to the best of our knowledge. Spectroscopic parameters were determined using the Judd–Ofelt theory and the measured absorption spectrum. The maximum emission cross section of the Ho3+-doped ZBYA glass is estimated to be 2.7 × 10−21 cm2 at 3906 nm. Additionally, fluorescence spectra and lifetimes of ZBYA glasses with different Ho3+ ion doping concentrations were measured. The results provide theoretical and experimental basis for better selection of rare-earth-doped …


Electric Field Control Of Fixed Magnetic Skyrmions For Energy Efficient Nanomagnetic Memory, Dhritiman Bhattacharya Jan 2020

Electric Field Control Of Fixed Magnetic Skyrmions For Energy Efficient Nanomagnetic Memory, Dhritiman Bhattacharya

Theses and Dissertations

To meet the ever-growing demand of faster and smaller computers, increasing number of transistors are needed in the same chip area. Unfortunately, Silicon based transistors have almost reached their miniaturization limits mainly due to excessive heat generation. Nanomagnetic devices are one of the most promising alternatives of CMOS. In nanomagnetic devices, electron spin, instead of charge, is the information carrier. Hence, these devices are non-volatile: information can be stored in these devices without needing any external power which could enable computing architectures beyond traditional von-Neumann computing. Additionally, these devices are also expected to be more energy efficient than CMOS devices …


Independent And Simultaneous Control Of Electromagnetic Wave Properties In Self-Collimating Photonic Crystals Using Spatial Variance, Jesus Javier Gutierrez Jan 2020

Independent And Simultaneous Control Of Electromagnetic Wave Properties In Self-Collimating Photonic Crystals Using Spatial Variance, Jesus Javier Gutierrez

Open Access Theses & Dissertations

Photonic crystals are engineered periodic structures that provide great control over electromagnetic waves. One of these mechanisms is self-collimation, in which the electromagnetic wave travels through the photonic crystal along an axis of the lattice without diffracting or spreading. This mechanism of self-collimation is a dispersion phenomenon, which is dependent on the unit cell's physical and geometrical characteristics. An algorithm for generating spatially variant lattices (SVL) was developed that can change geometrical properties in photonic crystals as a function of position, like unit cell orientation, fill fraction, symmetry, and others in a manner that is smooth, continuous, and virtually free …


Recent Developments In The Pyscf Program Package, Qiming Sun, Xing Zhang, Samragni Banerjee, Peng Bao, Marc Barbry, Nick S. Blunt, Nikolay A. Bogdanov, George H. Booth, Jia Chen, Zhi-Hao Cui, Janus J. Eriksen, Yang Gao, Sheng Gun, Jan Hermann, Matthew R. Hermes, Kevin Koh, Peter Koval, Susi Lehtola, Zhendong Li, Junzi Liu, Narbe Mardirossian, James D. Mcclain, Mario Motta, Bastien Mussard, Hung Q. Pham, Artem Pulkin, Wirawan Purwanto, Paul J. Robinson, Enrico Ronca, Elvira R. Sayfutyarova, Maximillian Scheurer, Henry F. Schurkus, James E.T. Smith, Chong Sun, Shi-Ning Sun, Shiv Upadhyay, Lucas K. Wagner, Xiao Wang, Alec White, James Daniel Whitfield, Mark J. Williamson, Sebastian Wouters, Jun Yang, Jason M. Yu, Tianyu Zhu, Timothy C. Berkelbach, Sandeep Sharma, Alexander Yu Sokolov, Garnet Kin-Lic Chan Jan 2020

Recent Developments In The Pyscf Program Package, Qiming Sun, Xing Zhang, Samragni Banerjee, Peng Bao, Marc Barbry, Nick S. Blunt, Nikolay A. Bogdanov, George H. Booth, Jia Chen, Zhi-Hao Cui, Janus J. Eriksen, Yang Gao, Sheng Gun, Jan Hermann, Matthew R. Hermes, Kevin Koh, Peter Koval, Susi Lehtola, Zhendong Li, Junzi Liu, Narbe Mardirossian, James D. Mcclain, Mario Motta, Bastien Mussard, Hung Q. Pham, Artem Pulkin, Wirawan Purwanto, Paul J. Robinson, Enrico Ronca, Elvira R. Sayfutyarova, Maximillian Scheurer, Henry F. Schurkus, James E.T. Smith, Chong Sun, Shi-Ning Sun, Shiv Upadhyay, Lucas K. Wagner, Xiao Wang, Alec White, James Daniel Whitfield, Mark J. Williamson, Sebastian Wouters, Jun Yang, Jason M. Yu, Tianyu Zhu, Timothy C. Berkelbach, Sandeep Sharma, Alexander Yu Sokolov, Garnet Kin-Lic Chan

University Administration Publications

PySCF is a Python-based general-purpose electronic structure platform that supports first-principles simulations of molecules and solids as well as accelerates the development of new methodology and complex computational workflows. This paper explains the design and philosophy behind PySCF that enables it to meet these twin objectives. With several case studies, we show how users can easily implement their own methods using PySCF as a development environment. We then summarize the capabilities of PySCF for molecular and solid-state simulations. Finally, we describe the growing ecosystem of projects that use PySCF across the domains of quantum chemistry, materials science, machine learning, and …


Nonlinear Optical Mechanisms In Semiconductors And Enhanced Nonlinearities At Epsilon-Near-Zero, Sepehr Ahmadzadeh Benis Jan 2020

Nonlinear Optical Mechanisms In Semiconductors And Enhanced Nonlinearities At Epsilon-Near-Zero, Sepehr Ahmadzadeh Benis

Electronic Theses and Dissertations, 2020-

Light does not interact with itself in linear optical materials. Such interactions occur only in non-linear optical (NLO) materials and typically require high intensity optical beams to be signifi-cant. The ever-increasing role of NLO, where intense light may change the properties of the me-dium, has created a pressing demand to invent materials for achieving more efficient light-light and light-matter interaction due to their potential capacity to augment and possibly replace cur-rent technologies with more efficient devices. There are numerous applications of NLO devices in fundamental science, technology, health, and defense such as all-optical computation and sig-nal processing, ultrashort laser technology, …


Attosecond Transient Absorption Spectroscopy In The Water Window, Andrew Chew Jan 2020

Attosecond Transient Absorption Spectroscopy In The Water Window, Andrew Chew

Electronic Theses and Dissertations, 2020-

The push to study the atomic and molecular dynamics at ever smaller time scales has been the main driving force for developing laser systems with ever shorter pulse durations. Thus far, picosecond lasers and femtosecond lasers have been used with great success in femtochemistry to study molecular dynamics such as molecular rotation and vibration, which all occur in the tens to hundreds of femtosecond. To study electron dynamics however, which are on the order of attoseconds, one needs attosecond laser sources to be able to have the time resolution required to probe ultrafast electron dynamics such as AC Stark shifts, …


Novel Fibers And Components For Space Division Multiplexing Technologies, Juan Carlos Alvarado Zacarias Jan 2020

Novel Fibers And Components For Space Division Multiplexing Technologies, Juan Carlos Alvarado Zacarias

Electronic Theses and Dissertations, 2020-

Passive devices and amplifiers for space division multiplexing are key components for future deployment of this technology and for the development of new applications exploring the spatial diversity of light. Some important devices include photonic lantern (PL) mode multiplexers supporting several modes, fan-in/fan-out (FIFO) devices for multicore fibers (MCFs), and multimode amplifiers capable of amplifying several modes with low differential modal gain penalty. All these components are required to overcome the capacity limit of single mode fiber (SMF) communication systems, driven by the growing data capacity demand. In this dissertation I propose and develop different passive components and amplifiers for …


Iterative Optical Diffraction Tomography For Reconstruction Of Multiply-Scattering Objects, Shengli Fan Jan 2020

Iterative Optical Diffraction Tomography For Reconstruction Of Multiply-Scattering Objects, Shengli Fan

Electronic Theses and Dissertations, 2020-

As a label-free, non-destructive, high-resolution, and quantitative imaging technique, optical diffraction tomography (ODT) has been widely used to image biological samples and microstructures, such as cells, tissues, and optical fibers. The refractive-index (RI) distribution of an object is reconstructed from multi-view measurements of diffracted fields emerging from the object. Typical ODT setups include the object rotating configuration (ORC) and the illumination scanning configuration (ISC). One major limitation of ODT is that it is only applicable to weakly-scattering objects. In this dissertation, novel methods have been developed to overcome the reconstruction difficulty caused by multiple scattering, so as to extend ODT …


Parallelized X-Ray Tracing With Gpu Ray-Tracing Engine, Joseph Ulseth Jan 2020

Parallelized X-Ray Tracing With Gpu Ray-Tracing Engine, Joseph Ulseth

Electronic Theses and Dissertations, 2020-

X-ray diffraction tomography (XDT) is used to probe material composition of objects, providing improved contrast between materials compared to conventional transmission based computed tomography (CT). In this work, a small angle approximation to Bragg's Equation of diffraction is coupled with parallelized computing using Graphics Processing Units (GPUs) to accelerate XDT simulations. The approximation gives rise to a simple yet useful proportionality between momentum transfer, radial distance of diffracted signal with respect to incoming beam's location, and depth of material, so that ray tracing may be parallelized. NVIDIA's OptiX ray-tracing engine, a parallelized pipeline for GPUs, is employed to perform XDT …


Midwave Vs Longwave Infrared Search And Track And Aerosol Scattering Target Acquisition Performance, Steven Butrimas Jan 2020

Midwave Vs Longwave Infrared Search And Track And Aerosol Scattering Target Acquisition Performance, Steven Butrimas

Electronic Theses and Dissertations, 2020-

The decision on whether to use a mid wave infrared (MWIR) or long wave infrared (LWIR) sensor for a given task can be a formidable verdict. The scope entails facts about the observable source, the atmospheric interactions, and the sensor parameters within the hardware device. Even when all the individual metrics are known, the combination ultimately determines whether a MWIR or LWIR sensor is more appropriate. Despite the vast number of variables at play, the reduction of inputs through focused studies can provide essential insight into MWIR and LWIR comparisons. This dissertation focuses on the roles of point source target …


Heterogeneous Integrated Photonics For Nonlinear Frequency Conversion And Polarization Diversity, Tracy Sjaardema Jan 2020

Heterogeneous Integrated Photonics For Nonlinear Frequency Conversion And Polarization Diversity, Tracy Sjaardema

Electronic Theses and Dissertations, 2020-

Silicon has proven to be one of the materials of choice for many integrated photonic applications. However, silicon photonics is limited by certain material shortcomings. Two shortcomings addressed in this work are zero second-order optical nonlinearity, and the lack of methods available to achieve broadband polarization diversity. Heterogeneous integrated solutions for these shortcomings of silicon photonics are presented in this work. First, nonlinear frequency conversion is demonstrated with thin-film lithium niobate on silicon substrates. The method for reaching the highest-achieved second-harmonic generation conversion efficiency, using active monitoring during periodic poling, is discussed. Additionally, a cascaded approach for generating higher-order harmonics …


High Performance Micro-Scale Light Emitting Diode Display, Fangwang Gou Jan 2020

High Performance Micro-Scale Light Emitting Diode Display, Fangwang Gou

Electronic Theses and Dissertations, 2020-

Micro-scale light emitting diode (micro-LED) is a potentially disruptive display technology because of its outstanding features such as high dynamic range, good sunlight readability, long lifetime, low power consumption, and wide color gamut. To achieve full-color displays, three approaches are commonly used: 1) to assemble individual RGB micro-LED pixels from semiconductor wafers to the same driving backplane through pick-and-place approach, which is referred to as mass transfer process; 2) to utilize monochromatic blue micro-LED with a color conversion film to obtain a white source first, and then employ color filters to form RGB pixels, and 3) to use blue or …


Development Of High-Power Single-Mode Yb-Doped Fiber Amplifiers And Beam Analysis, Steffen Wittek Jan 2020

Development Of High-Power Single-Mode Yb-Doped Fiber Amplifiers And Beam Analysis, Steffen Wittek

Electronic Theses and Dissertations, 2020-

High-power fiber laser systems enjoy a widespread use in manufacturing, medical, and defense applications as well as scientific research, due to their remarkable power scalability, high electrical to optical efficiency, compactness and ruggedness. However, single-mode fiber power scaling has stagnated in the past years, primarily due to the onset of nonlinear effects such as stimulated Brillouin/Raman scattering and transverse modal instabilities. This thesis addresses the analysis and mitigation of transverse modal instabilities in high-power fiber amplifiers. I describe the high-power fiber amplifier testbed that I set up to test fibers fabricated in house. I will show our results of a …


Investigation Of Phonon Polaritons In An Hbn Gan Heterostructure, Catherine G. O'Hearn Jan 2020

Investigation Of Phonon Polaritons In An Hbn Gan Heterostructure, Catherine G. O'Hearn

Graduate Theses, Dissertations, and Problem Reports

There have been many great advances in the generation and manipulation of optics in the visible and near infrared (IR) range over the past decade. This is largely due to plasmonic enhancement, which has led to new technology in biosensing and molecule detection, solid-state lighting, and solar energy harvesting. The field of plasmonics uses quanta of plasma oscillations, plasmons, formed from the interaction between electromagnetic radiation and free electrons to enhance optical near field magnitudes. However, there is still a large region of the electromagnetic spectrum, covering the mid-infrared (MIR) and terahertz (THz) regions, ranging from 3 μm to 1 …


Synthesis Of Graphene Using Plasma Etching And Atmospheric Pressure Annealing: Process And Sensor Development, Andrew Robert Graves Jan 2020

Synthesis Of Graphene Using Plasma Etching And Atmospheric Pressure Annealing: Process And Sensor Development, Andrew Robert Graves

Graduate Theses, Dissertations, and Problem Reports

Having been theorized in 1947, it was not until 2004 that graphene was first isolated. In the years since its isolation, graphene has been the subject of intense, world-wide study due to its incredibly diverse array of useful properties. Even though many billions of dollars have been spent on its development, graphene has yet to break out of the laboratory and penetrate mainstream industrial applications markets. This is because graphene faces a ‘grand challenge.’ Simply put, there is currently no method of manufacturing high-quality graphene on the industrial scale. This grand challenge looms particularly large for electronic applications where the …