Electromagnetics and Photonics Commons^™

Simulation Design For Photovoltaics Using Finite Difference Time Domain And Quadratic Complex Rational Function Methods, Jacob R. Duritsch, Haejun Chung, Peter Bermel

The Summer Undergraduate Research Fellowship (SURF) Symposium

Photovoltaics (PV) can in principle supply enough renewable energy to offset a great deal of fossil fuel usage. To achieve this transition, it is critical to develop improved PV cells with decreased material costs and improved efficiencies. This goal can be greatly facilitated by a tool simulating the absorption and efficiency of experimentally relevant 3-D PV designs made of realistic materials, including those that have not yet been discovered. By incorporating the quadratic complex rational function algorithm (QCRF) with the finite difference time domain methods (FDTD), simulations can include frequency response and optical properties, while allowing full customization of tandem …

Mass-Positioning Of Nanodiamonds Using Squeegee Technique, Ran Cui, Mikhail Y. Shalaginov, Vladimir M. Shalaev

The Summer Undergraduate Research Fellowship (SURF) Symposium

Fluorescent color centers in diamond nanocrystals have recently become the focus of researchers because of their potential applications in quantum information processing, nano-sensing, biomarking, and bioimaging. One of the biggest challenges in working with nanodiamonds is how to position them precisely and efficiently to create strong interaction with nanoscale photonic structures. The most popular methods to position nanodiamonds are spin-coating and transporting via scanning probe microscope tip. On the one hand, spin-coating, where nanodiamonds are randomly located, is not precise; on the other hand, the tip-based technique, where a single nanodiamond is picked and dropped, is tedious and time-consuming. Hence, …

Simplified Generation Of The Input Models Of Object Oriented Micromagnetic Framework (Oommf), Jinyang Yu, Rafatul Faria, Supriyo Datta, Tanya A. Faltens

The Summer Undergraduate Research Fellowship (SURF) Symposium

Object Oriented MicroMagnetic Framework (OOMMF) is a micromagnetic simulation tool. It takes a memory initialization file (MIF) as the input and outputs various forms of data such as data table, graph and magnetic configuration plots. It is accurate and fast compared to other existing tools such as MATLAB. Few experimentalists used it in the past, however, due to two main reasons. First, OOMMF requires a specific version of programming environment on the local computer which is difficult to be installed. Second, MIF file is very complicated to code and it also requires users to read a lengthy guidelines. Our solution …

Creation Of Carbon Nanotube Based Biosensors Through Dielectrophoretic Assembly, Nilan S. Mani, Steve Kim, Kaushik Annam, Danielle Bane, Guru Subramanyam

Electrical and Computer Engineering Faculty Publications

Due to their excellent electrical, optical, and mechanical properties, nanosized single wall carbon nanotubes (SWNTs) have attracted significant attention as a transducing element in nano-bio sensor research. Controlled assembly, device fabrication, and bio-functionalization of the SWNTs are crucial in creating the sensors. In this study, working biosensor platforms were created using dielectrophoretic assembly of single wall carbon nanotubes (SWNTs) as a bridge between two gold electrodes. SWNTs in a commercial SDS surfactant solution were dispensed in the gap between the two gold electrodes, followed by applying an ac voltage across the two electrodes. The dielectrophoresis aligns the CNTs and forms …

Automatic Registration Of Optical Aerial Imagery To A Lidar Point Cloud For Generation Of City Models, Bernard Olushola Abayowa, Alper Yilmaz, Russell C. Hardie

Electrical and Computer Engineering Faculty Publications

This paper presents a framework for automatic registration of both the optical and 3D structural information extracted from oblique aerial imagery to a Light Detection and Ranging (LiDAR) point cloud without prior knowledge of an initial alignment. The framework employs a coarse to fine strategy in the estimation of the registration parameters. First, a dense 3D point cloud and the associated relative camera parameters are extracted from the optical aerial imagery using a state-of-the-art 3D reconstruction algorithm. Next, a digital surface model (DSM) is generated from both the LiDAR and the optical imagery-derived point clouds. Coarse registration parameters are then …

Dna Based Electrolyte/Separator For Lithium Battery Application, Jitendra Kumar, Fahima Ouchen-Bouchendouka, Devin A. Smarra, Guru Subramanyam, James Grote

Electrical and Computer Engineering Faculty Publications

In this study, we demonstrated the use of DNA-CTMA (DC) in combination with PolyVinylidene Fluoride (PVDF) as a host matrix or separator for Lithium based electrolyte to form solid polymer/gel like electrolyte for potential application in Li-ion batteries.

The addition of DC provided a better thermal stability of the composite electrolyte as shown by the thermos-gravimetric analysis (TGA). The AC conductivity measurements suggest that the addition of DC to the gel electrolyte had no effect on the overall ionic conductivity of the composite. The obtained films are flexible with high mechanical stretch-ability as compared to the gel type electrolytes only.

Design Method For Wideband Circularly Polarized Slot Antennas, Adam Narbudowicz, Matthias John, Vit Sipal, Xiulong Bao, Max Ammann

Articles

A compact ultrawideband (UWB) circularly polarized (CP) slot antenna is proposed with a methodology for automated reoptimization for packaging with proprietary devices. The slot structure employs a dual-feed with an integrated compact UWB phase shifter. The design process involves an advanced optimization algorithm and demonstrates the use of spline curves for generation of CP signals. These allow easy optimization, while preserving phase coherency across a wideband. The prototyped antennahas a CP bandwidth of 54% (from 3.2 to 6.1 GHz).

Secure Transmission And Retrieval Of Images In Conjunction With Steganography Using Chaos In Nonlinear Acousto-Optic Feedback, Monish Ranjan Chatterjee, Fares S. Almehmadi

Electrical and Computer Engineering Faculty Publications

Digital images are encrypted onto a chaotic carrier in a Bragg cell under hybrid nonlinear feedback and secure data is embedded into the system via steganography. System robustness (with and without channel noise) is analyzed vis-a-vis information security.

Towards Circularly Polarized Reconfigurable Huygens Source, Adam Narbudowicz, Max Ammann, Dirk Heberling

Conference papers

The paper investigates an array of two reconfigurable circularly-polarized antennas with omnidirectional radiation pattern. The results are based on a previously reported antenna, which offers a steerable dipolelike radiation pattern. Its capabilities allow reception of a signal from practically any direction with steering realized by rotation of the pattern around a single axis. In this paper we propose to extend this functionality by forming an array of two such antennas oriented as a Huygens source. Simulations demonstrate six distinctive radiation patterns, each illuminating a different sector of the surrounding sphere. This allows increased antenna gain and simplification of the steering …

Planar Dual-Mode Mimo Antenna With Enhanced Bandwidth, Adam Narbudowicz, Slawomir Koziel, Max Ammann, Dirk Heberling

Conference papers

The paper proposes a dual-port pa MIMO applications, optimized using optimization techniques. The antenna uses two (TM100 and TM200) to generate two indep patterns. To enhance the bandwidth of TM200 ground plane was realized as a meshed surfac approach provides 97 MHz of bandwidth, while profile of 1.5 mm between the patch and the g 3.5). The numerical optimization involved 12 adj parameters.

Fabrication Of Sub-10 Nm Metallic Structures Via Nanomasking Technique For Plasmonic Enhancement Applications, Stephen Joseph Bauman

Graduate Theses and Dissertations

One area of nanoscience that has become popular in recent years is the study of optics at the nanoscale. Due to enhanced fabrication techniques, new geometries and improved dimensional resolutions have been allowing the creation of nanostructures for use in this area. Nanoscale geometries cause unique optical effects such as enhancement of the signal’s electric field strength at the surface of a substrate. Specifically, structures separated by nanogaps (10 nm and smaller) have been shown to exhibit strong field enhancement within the gaps. This has opened up the potential for surface enhanced spectroscopies, enhanced absorption for photovoltaics, and improved sensing …

Numerical Simulation Of Terahertz Wave Interaction With Breast Cancer Tumor Tissue Sections, Abayomi Omotola Omolewu

Graduate Theses and Dissertations

This thesis presents numerical simulation of terahertz (THz) wave interaction with breast cancer tumor tissue sections. The obtained results are expressed in THz images of heterogeneous material that mimics the excised breast cancer tissue sections. The finite-element software package ANSYS High Frequency Structural Simulator (HFSS) was used in this work. HFSS is a full wave frequency domain three-dimensional (3D) electromagnetic simulation package. In this work, four breast cancer tissue models based on pathology images were simulated and images of the models were obtained at 1 THz. An incident Gaussian beam was raster scanned over tissue model configurations and the reflected …

The Effects Of Strain And Vacancies On The Electric And Vibrational Properties Of Ferroelectric Batio3 From First-Principles, Aldo Serge Michael Raeliarijaona

Graduate Theses and Dissertations

The studies of ferroelectricity (FE) are of technological significance because of the multitude of applicable properties that ferroelectric materials exhibit. The mastery, and control of these properties necessitate the knowledge of the fundamental physics governing these insulating materials.

In this dissertation I present the results of first-principles investigations of the behavior of the fundamental ferroelectric properties under strain, and in the presence of vacancies. In the first part I introduce the important FE properties, their common behavior, and their numerous valuable applications. Following this background on FEs, a review of theoretical methods is presented with topics such as: Density Functional …

A Transfer Function Based Frequency Model For Propagation Of A Chaos Wave Through Modified Von Karman Turbulence Under Various Chaos And Turbulence Conditions, Monish Ranjan Chatterjee, Fathi H.A. Mohamed

Electrical and Computer Engineering Faculty Publications

Complex phasor fields for electromagnetic wave propagation through von Karman turbulence and acousto-optic RF chaos are derived en route to the effective transfer function between chaos and narrow turbulence. Results are tested for several turbulence and chaos conditions.

Minimizing Sheet Resistance Of Organic Photovoltaic Cell Top Contact Electrode Layer: Silver Nanowire Concentration Vs. Conductive Polymer Doping Concentration, Caitlyn Cook

Materials Engineering

The top contact electrode layers of nine organic photovoltaic cells were prepared with two varying factors: three Silver nanowire (AgNW) densities deposited on a conductive polymer doped with three concentrations. Silver’s low sheet resistance of 20-Ω/sq is hypothesized to lower the sheet resistance of the anode layer and thus enhance the overall efficiency of the cell. Four-point probe measurements indicated that increasing AgNW density in the top contact electrode layer of an organic photovoltaic cell significantly reduces sheet resistance from 52.2k-Ω/sq to 18.0 Ω/sq. Although an increase in doping concentration of the conductive polymer reduced sheet resistance in low AgNW …

Emergence Of Negative Index In A Lossy Chiral Metamaterial Under First-Order Material Dispersion, Monish Ranjan Chatterjee, Tarig A. Algadey

Electrical and Computer Engineering Faculty Publications

For a lossless dispersive chiral material, negative index (NIM) occurred only by use of parametric analysis (and not via practical models) to first-order. These findings are re-visited for the lossy problem and the results are compared.

Sweep Stability Characterization Of A Vernier-Tuned Distributed Bragg Reflector (Vt-Dbr) All-Semiconductor Tunable Swept Laser System At 1550 Nm For Sensing Applications, Roric Christian Martens Biersach

Master's Theses

The short-term jitter and longer-term wander of the frequency sweep profile of a Vernier-Tuned Distributed Bragg Reflector (VT-DBR) laser at 1550 nm used in optical coherence tomography (OCT) and other sensing applications is characterized in this work. The VT-DBR has demonstrated success in source-swept OCT (SSOCT), performing both intensity and phase-sensitive OCT.

The purpose of this paper is to investigate one of the unique aspects of the VT-DBR laser that makes it successful in OCT: the stability of the linear optical frequency sweep. A highly stable linear optical frequency sweep implies benefits for further fiber sensing applications including fiber Bragg …

The Electric Reel For Soccer Fields, Stephen Taylor

Electrical Engineering

Painting a soccer field consumes too much time. The process of reeling the string after laying out string along the field needs to improve. As a result, my project addresses improvements in how the workers retrieve the string through the production of an electric reel. This electric reel allows the worker to have control of the speed, direction, and on/off state of the device. Direction control allows the user ability to reel and unwind the string. Variable speed allows the user to control how fast the reel unwinds and reels the string. The device gathers string in an orderly manner …

Veloelectric: Creating A Device That Harvests Energy From Bicycles, Austin Hall, Daniel Stohr, Tj Fox

Mechanical Engineering

Long distance mountain bikers, bike-packers, and many bikers in developing countries rely on electrical devices for safety and communication. These specific groups of people operate in areas with little to no electricity, and often times have no power to sustain their devices. The purpose of this Cal Poly senior project, VeloElectric, was to design, build, and test a kinetic energy harvester for bicycles that can be used to charge common mobile devices via USB. This senior project team created a device that attaches directly to a bicycle and uses vibrations to generate energy, which in turn powers a variety of …

Characterization Of Two Vernier-Tuned Distributed Bragg Reflector (Vt-Dbr) Lasers Used In Swept Source Optical Coherence Tomography (Ss-Oct), Greg M. Bergdoll

Master's Theses

Insight Photonic Solutions Inc. has continued to develop their patented VT-DBR laser design; these wavelength tunable lasers promise marked image-quality and acquisition time improvements in SS-OCT applications.

To be well suited for SS-OCT, tunable lasers must be capable of producing a highly linear wavelength sweep across a tuning range well-matched to the medium being imaged; many different tunable lasers used in SS-OCT are compared to identify the optimal solution.

This work electrically and spectrally characterizes two completely new all-semiconductor VT-DBR designs to compare, as well. The Neptune VT-DBR, an O-band laser, operates around the 1310 nm range and is a …