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Efficiency Enhancement Of Perovskite Solar Cells With Plasmonic Nanoparticles: A Simulation Study, Ali Hajjiah, Ishac Kandas, Nader Shehata 2018 Kuwait University

Efficiency Enhancement Of Perovskite Solar Cells With Plasmonic Nanoparticles: A Simulation Study, Ali Hajjiah, Ishac Kandas, Nader Shehata

Biology Faculty Publications

Recently, hybrid organic-inorganic perovskites have been extensively studied due to their promising optical properties with relatively low-cost and simple processing. However, the perovskite solar cells have some low optical absorption in the visible spectrum, especially around the red region. In this paper, an improvement of perovskite solar cell efficiency is studied via simulations through adding plasmonic nanoparticles (NPs) at the rear side of the solar cell. The plasmonic resonance wavelength is selected to be very close to the spectrum range of lower absorption of the perovskite: around 600 nm. Both gold and silver nanoparticles (Au and Ag NPs) are selected ...


Charge State Dynamics And Quantum Sensing With Defects In Diamond, Jacob D. Henshaw 2018 The Graduate Center, City University of New York

Charge State Dynamics And Quantum Sensing With Defects In Diamond, Jacob D. Henshaw

All Dissertations, Theses, and Capstone Projects

In recent years, defect centers in wide band gap semiconductors such as diamond, have received significant attention. Defects offer great utility as single photon emitters, nanoscale sensors, and quantum memories and registers for quantum computation. Critical to the utility of these defects, is their charge state.

In this dissertation, experiments surrounding the charge state dynamics and the carrier dynamics are performed and analyzed. Extensive studies of the ionization and recombination processes of defects in diamond, specifically, the Nitrogen Vacancy (NV) center, have been performed. Diffusion of ionized charge carriers has been imaged indirectly through the recapture of said carriers by ...


From Photon To Neuron Chapter 16: Tunneling Of Photons And Electrons, Philip C. Nelson 2018 University of Pennsylvania

From Photon To Neuron Chapter 16: Tunneling Of Photons And Electrons, Philip C. Nelson

Department of Physics Papers

This chapter extends Part III of the book From Photon to Neuron (Princeton Univ Press 2017). This preliminary version is made freely available as-is in the hope that it will be useful.


In Vivo Vascular Imaging With Photoacoustic Microscopy, Hsun-Chia Hsu 2018 Washington University in St. Louis

In Vivo Vascular Imaging With Photoacoustic Microscopy, Hsun-Chia Hsu

Engineering and Applied Science Theses & Dissertations

Photoacoustic (PA) tomography (PAT) has received extensive attention in the last decade for its capability to provide label-free structural and functional imaging in biological tissue with highly scalable spatial resolution and penetration depth. Compared to modern optical modalities, PAT offers speckle-free images and is more sensitive to optical absorption contrast (with 100% relative sensitivity). By implementing different regimes of optical wavelength, PAT can be used to image diverse light-absorbing biomolecules. For example, hemoglobin is of particular interest in the visible wavelength regime owing to its dominant absorption, and lipids and water are more commonly studied in the near-infrared regime.

In ...


Scattering Of Few Photon Fields By Two Level Systems In A One Dimensional Geometry, William Konyk 2018 University of Arkansas, Fayetteville

Scattering Of Few Photon Fields By Two Level Systems In A One Dimensional Geometry, William Konyk

Theses and Dissertations

Recent experimental progress has realized strong, efficient coupling of effective two level systems to waveguides. We study the scattering of multimode photons from such emitters coupled losslessly to the confined geometry of a one dimensional waveguide. We develop novel techniques for describing the scattered state of both single and multi-photon wavepackets and explore how such wavepackets interact with arrays of emitters coupled to a one dimensional waveguide. Finally, we apply these techniques and analyze the capability of two particular systems to act as a quantum conditional logic gate.


Investigation Of Spin And Dip-Coating Phase Change Chalcogenide Materials As A Novel Technique For Coating And Functionalizing Conformal Optics, Paul Vecchio 2018 Ursinus College

Investigation Of Spin And Dip-Coating Phase Change Chalcogenide Materials As A Novel Technique For Coating And Functionalizing Conformal Optics, Paul Vecchio

Physics and Astronomy Summer Fellows

Chalcogenide glasses (ChGs) have excellent infrared (IR) transparency ranging up to 20 μm, large nonlinear refractive indices, and tailorable thermo-optic coefficients (dn/dT) that have great potential for applications in detectors, sensors, waveguides, imaging devices, photonic waveguides, acousto-optics, and optical devices. Spin and dip coating ChGs from solution is a low-cost, simple, and scalable method for depositing films over a large area. In this study, we utilize the novel approach of spin and dip coating to create thin ChG films of arsenic trisulfide (As2S3) and arsenic selenide (As2Se3). To realize the full potential of ...


Novel Compact Narrow-Linewidth Mid-Infrared Lasers For Sensing Applications, Behsan Behzadi 2018 University of New Mexico - Main Campus

Novel Compact Narrow-Linewidth Mid-Infrared Lasers For Sensing Applications, Behsan Behzadi

Optical Science and Engineering ETDs

The mid-infrared (2-14 μm) spectral region contains the strong absorption lines of many important molecular species, which make this region crucial for several well-know applications such as spectroscopy, chemical and biochemical sensing, security, and industrial monitoring. To fully exploit this region through absorption spectroscopic techniques, compact and low-cost narrow-linewidth (NLW) mid-infrared (MIR) laser sources are of primary importance.

This thesis is focused on three novel compact NLW MIR lasers: demonstration and characterization of a new glass-based spherical microlaser, investigation of the performance of a novel fiber laser, and the design of a monolithic laser on a silicon chip. Starting with ...


Design, Fabrication, And Characterization Of A One-Dimensional Single-Material Polarizing Photonic Crystal, Ehsan Ordouie 2018 Rose-Hulman Institute of Technology

Design, Fabrication, And Characterization Of A One-Dimensional Single-Material Polarizing Photonic Crystal, Ehsan Ordouie

Graduate Theses - Physics and Optical Engineering

We examine a multilayered one-dimensional (1D) polarizing photonic crystal designed and fabricated out of a single material. This polarizer is designed for high reflection of the s polarization and low reflection of p polarization at the wavelength of 632.8 nm. This device is fabricated implementing the oblique angle deposition technique to produce six-bilayers of alternating high to low indices of titanium dioxide using e-beam PVD for depositing on top of a fused silica substrate. For modeling, we used transfer-matrix method and numerical finite-difference time-domain analysis to simulate behavior of the 1D photonic bandgap structure. Both model and simulation predict ...


Laser-Induced Recoverable Surface Patterning On Ni50ti50 Shape Memory Alloys, Saidjafarzoda Ilhom 2018 Western Kentucky University

Laser-Induced Recoverable Surface Patterning On Ni50ti50 Shape Memory Alloys, Saidjafarzoda Ilhom

Masters Theses & Specialist Projects

Shape memory alloys (SMAs) are a unique class of smart materials exhibiting extraordinary properties with a wide range of applications in engineering, biomedical, and aerospace technologies. In this study, an advanced, efficient, low-cost, and highly scalable laser-assisted imprinting method with low environmental impact to create thermally controllable surface patterns is reported. Two different imprinting methods were carried out mainly on Ni50Ti50 (at. %) SMAs by using a nanosecond pulsed Nd:YAG laser operating at 1064 nm wavelength and 10 Hz frequency. First, laser pulses at selected fluences were directly focused on the NiTi surface, which generated pressure pulses of up to ...


A System For Conducting Laser-Induced Fluorescence Measurements On Gas Mixtures Exposed To Alpha Radiation, Patrick Ables 2018 The University of Southern Mississippi

A System For Conducting Laser-Induced Fluorescence Measurements On Gas Mixtures Exposed To Alpha Radiation, Patrick Ables

Master's Theses

This paper documents modifications to an existing vacuum system to allow laser-induced fluorescence spectroscopy measurements within simulated atmospheres under a variety of conditions. This added capability will expand the laboratory’s ability to experimentally validate a computational model that calculates the effects of radiation within the atmosphere. The computational model could reveal radiation-induced chemical products that can be used to develop an alternative detection method that can be implemented from a safe distance. The selection of molecules for experimental validation has been limited to those which can be detected utilizing cavity ringdown spectroscopy. The current model indicates nitric oxide and ...


Super‐Resolution Imaging Of Amyloid Structures Over Extended Times By Using Transient Binding Of Single Thioflavin T Molecules, Kevin Spehar, Tianben Ding, Yuanzi Sun, Niraja Kedia, Jin Lu, George R. Nahass, Matthew D. Lew, Jan Bieschke 2018 Washington University in St. Louis

Super‐Resolution Imaging Of Amyloid Structures Over Extended Times By Using Transient Binding Of Single Thioflavin T Molecules, Kevin Spehar, Tianben Ding, Yuanzi Sun, Niraja Kedia, Jin Lu, George R. Nahass, Matthew D. Lew, Jan Bieschke

Electrical & Systems Engineering Publications and Presentations

Oligomeric amyloid structures are crucial therapeutic targets in Alzheimer's and other amyloid diseases. However, these oligomers are too small to be resolved by standard light microscopy. We have developed a simple and versatile tool to image amyloid structures by using thioflavin T without the need for covalent labeling or immunostaining. The dynamic binding of single dye molecules generates photon bursts that are used for fluorophore localization on a nanometer scale. Thus, photobleaching cannot degrade image quality, allowing for extended observation times. Super‐resolution transient amyloid binding microscopy promises to directly image native amyloid by using standard probes and record ...


Imaging The Three-Dimensional Orientation And Rotational Mobility Of Fluorescent Emitters Using The Tri-Spot Point Spread Function, Oumeng Zhang, Jin Lu, Tianben Ding, Matthew D. Lew 2018 Washington University in St Louis

Imaging The Three-Dimensional Orientation And Rotational Mobility Of Fluorescent Emitters Using The Tri-Spot Point Spread Function, Oumeng Zhang, Jin Lu, Tianben Ding, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

Fluorescence photons emitted by single molecules contain rich information regarding their rotational motions, but adapting single-molecule localization microscopy (SMLM) to measure their orientations and rotational mobilities with high precision remains a challenge. Inspired by dipole radiation patterns, we design and implement a Tri-spot point spread function (PSF) that simultaneously measures the three-dimensional orientation and the rotational mobility of dipole-like emitters across a large field of view. We show that the orientation measurements done using the Tri-spot PSF are sufficiently accurate to correct the anisotropy-based localization bias, from 30 nm to 7 nm, in SMLM. We further characterize the emission anisotropy ...


Assembling And Characterizing The Efficiency Of An Injection Locked Laser System For Cold Neutral Atom Optical Traps, Alexandra Papa Crawford 2018 California Polytechnic State University, San Luis Obispo

Assembling And Characterizing The Efficiency Of An Injection Locked Laser System For Cold Neutral Atom Optical Traps, Alexandra Papa Crawford

Physics

Creating a quantum computer requires a system of particles that can be well-controlled to achieve quantum operations. We need a large array of these particles – called qubits – with long coherence times, which can be initialized, operated on by single and two qubit gates, and read out. For neutral atoms, the qubit states are stable ground states that interact minimally with the environment, leading to long coherence times. Experimentally, the qubits are manipulated using carefully timed laser beam pulses with controlled frequency and intensity, but the outstanding issue for optically trapping cold atoms is finding a light pattern that can hold ...


Enabling Autonomous Navigation For Affordable Scooters, Kaikai Liu, Rajathswaroop Mulky 2018 San Jose State University

Enabling Autonomous Navigation For Affordable Scooters, Kaikai Liu, Rajathswaroop Mulky

Faculty Publications

Despite the technical success of existing assistive technologies, for example, electric wheelchairs and scooters, they are still far from effective enough in helping those in need navigate to their destinations in a hassle-free manner. In this paper, we propose to improve the safety and autonomy of navigation by designing a cutting-edge autonomous scooter, thus allowing people with mobility challenges to ambulate independently and safely in possibly unfamiliar surroundings. We focus on indoor navigation scenarios for the autonomous scooter where the current location, maps, and nearby obstacles are unknown. To achieve semi-LiDAR functionality, we leverage the gyros-based pose data to compensate ...


Fluorescence Guided Tumor Imaging: Foundations For Translational Applications, Jessica P. Miller 2018 Washington University in St. Louis

Fluorescence Guided Tumor Imaging: Foundations For Translational Applications, Jessica P. Miller

Engineering and Applied Science Theses & Dissertations

Optical imaging for medical applications is a growing field, and it has the potential to improve medical outcomes through its increased sensitivity and specificity, lower cost, and small instrumentation footprint as compared to other imaging modalities. The method holds great promise, ranging from direct clinical use as a diagnostic or therapeutic tool, to pre-clinical applications for increased understanding of pathology. Additionally, optical imaging uses non-ionizing radiation which is safe for patients, so it can be used for repeated imaging procedures to monitor therapy, guide treatment, and provide real-time feedback. The versatile features of fluorescence-based optical imaging make it suited for ...


Developing Photoacoustic Tomography Devices For Translational Medicine And Basic Science Research, Tsz Wai Wong 2018 Washington University in St. Louis

Developing Photoacoustic Tomography Devices For Translational Medicine And Basic Science Research, Tsz Wai Wong

Engineering and Applied Science Theses & Dissertations

Photoacoustic (PA) tomography (PAT) provides volumetric images of biological tissue with scalable spatial resolutions and imaging depths, while preserving the same imaging contrast—optical absorption. Taking the advantage of its 100% sensitivity to optical absorption, PAT has been widely applied in structural, functional, and molecular imaging, with both endogenous and exogenous contrasts, at superior depths than pure optical methods. Intuitively, hemoglobin has been the most commonly studied biomolecule in PAT due to its strong absorption in the visible wavelength regime.

One of the main focuses of this dissertation is to investigate an underexplored wavelength regime—ultraviolet (UV), which allows us ...


Dispersive Quantum Interface With Atoms And Nanophotonic Waveguides, Xiaodong Qi 2018 University of New Mexico

Dispersive Quantum Interface With Atoms And Nanophotonic Waveguides, Xiaodong Qi

Physics & Astronomy ETDs

Strong coupling between atoms and light is critical for quantum information processing and precise sensing. A nanophotonic waveguide is a promising platform for realizing an atom-light interface that reaches the strong coupling regime. In this dissertation, we study the dispersive response theory of the nanowaveguide system as the means to create an entangling atom-light interface, with applications to quantum non-demolition (QND) measurement and spin squeezing.

We calculate the dyadic Green's function, which determines the scattering of light by atoms in the presence of a nanowaveguide, and thus the phase shift and polarization rotation induced on the guided light. The ...


Gain Modeling Of Erbium-Doped Fiber Amplifiers Pumped At 980nm, Deepak Charles Baskar 2018 Rose-Hulman Institute of Technology

Gain Modeling Of Erbium-Doped Fiber Amplifiers Pumped At 980nm, Deepak Charles Baskar

Graduate Theses - Physics and Optical Engineering

Erbium-Doped Fiber Amplifiers (EDFA) are one of the most widely used optical amplifiers in the field of optical communications and fiber lasers. Theoretical models based on the rate equations, therefore, were developed to predict the performance of such amplifiers. The goal of this thesis is to provide a numerical model for EDFAs and verify its validity through experimental measurements. Two computer programs based on two different numerical methods (the Finite Difference method and the 4th Order Runge-Kutta Method) to solve differential equations were written. The different fiber parameters to build the model including absorption and emission crosssections and scattering losses ...


Near Bandgap Two-Photon Excited Luminescence Of Inas Quantum Dots, Xian Hu 2018 University of Arkansas, Fayetteville

Near Bandgap Two-Photon Excited Luminescence Of Inas Quantum Dots, Xian Hu

Theses and Dissertations

Semiconductor quantum dots (QDs) confine carriers in three dimensions, resulting in atomic-like energy levels as well as size-dependent electrical and optical properties. Self-assembled III-V QD is one of the most studied semiconductor QDs thanks to their well-established fabrication techniques and versatile optical properties. This dissertation presents the photoluminescence (PL) study of the InAs/GaAs QDs with both above bandgap continuous-wave excitation (one-photon excitation) and below-bandgap pulse excitation (two-photon excitation). Samples of ensemble QDs, single QD (SQD), and QDs in a micro-cavity, all grown by molecular beam epitaxy, are used in this study. Morphology of these samples was examined using atomic ...


Photonic Tools For Advanced Sensing And Imaging At The Nanoscale., Jafar Hamed Ghithan 2018 University of Louisville

Photonic Tools For Advanced Sensing And Imaging At The Nanoscale., Jafar Hamed Ghithan

Electronic Theses and Dissertations

This dissertation reports a novel bio-sensing strategy based on single-mode, electro-active, integrated optical waveguide (SM-EA-IOW) platforms. It also reports the development of a super-resolved far-field optical imaging tool to enable optical, electronic, and spectroelectrochemical investigations at the nanoscale. SM-EA-IOW platforms with its outstanding sensitivity for spectroelectrochemical interrogation was combined with a sandwich bioassay for the development of a novel immunosensing based strategy for label-free detection of infectious pathogens. The strategy begins with the functionalization of the electroactive waveguide surface with a capturing antibody aimed at a specific target analyte. Once the target analyte is bound to the photonic interface, it ...


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