Dense Periodical Patterns In Photonic Devices: Technology For Fabrication And Device Performance,
2016
Wayne State University
Dense Periodical Patterns In Photonic Devices: Technology For Fabrication And Device Performance, Sabarish Chandramohan
Wayne State University Dissertations
For the fabrication, focused ion beam parameters are investigated to successfully fabricate dense periodical patterns, such as gratings, on hard transition metal nitride such as zirconium nitride. Transition metal nitrides such as titanium nitride and zirconium nitride have recently been studied as alternative materials for plasmonic devices because of its plasmonic resonance in the visible and near-infrared ranges, material strength, CMOS compatibility and optical properties resembling gold. Coupling of light on the surface of these materials using sub-micrometer gratings gives additional capabilities for wider applications. Here we report the fabrication of gratings on the surface of zirconium nitride using gallium …
Plasma Temperature Measurements In The Context Of Spectral Interference,
2016
University of Central Florida
Plasma Temperature Measurements In The Context Of Spectral Interference, Brandon Seesahai
Honors Undergraduate Theses
The path explored in this thesis is testing a plasma temperature measurement approach that accounts for interference in a spectrum. The Atomic Emission Spectroscopy (AES) technique used is called Laser Induced Breakdown Spectroscopy (LIBS) and involves focusing a laser pulse to a high irradiance onto a sample to induced a plasma. Spectrally analyzing the plasma light provides a "finger print" or spectrum of the sample. Unfortunately, spectral line broadening is a type of interference encountered in a LIBS spectrum because it blends possible ionic or atomic transitions that occur in plasma. To make use of the information or transitions not …
Intrinsic Modulation Response Modeling And Analysis For Lithographic Vertical-Cavity Surface-Emitting Lasers,
2016
University of Central Florida
Intrinsic Modulation Response Modeling And Analysis For Lithographic Vertical-Cavity Surface-Emitting Lasers, Mingxin Li
Electronic Theses and Dissertations
Vertical-cavity surface-emitting lasers (VCSELs) have been greatly improved and successfully commercialized over the past few decades owing to their ability to provide both mode and current confinement that enables low energy consumption, high efficiency and high modulation speed. However, further improvement of oxide VCSELs is limited by the nature of the oxide aperture because of self-heating, internal strain and difficulties in precise size control. In this dissertation, VCSELs using lithographic approach are demonstrated to overcome the limitations of oxide VCSELs, in which an intra-cavity phase shifting mesa is applied to define the device size and provide optical mode and electrical …
Ultrafast Mechanisms Of Nonlinear Refraction And Two-Photon Photochromism,
2016
University of Central Florida
Ultrafast Mechanisms Of Nonlinear Refraction And Two-Photon Photochromism, Peng Zhao
Electronic Theses and Dissertations
Derived from a material's third-order nonlinearity, nonlinear refraction (NLR) occurs at any wavelength in any material, and may exhibit noninstantaneous dynamics depending on its physical origins. The main subject of this dissertation is to investigate the underlying mechanisms responsible for the NLR response in different phases of matter, e.g. liquids, gases, and semiconductors, by extensively using our recently developed ultrafast Beam Deflection (BD) technique. An additional subject includes the characterization of a novel two-photon photochromic molecule. In molecular liquids, the major nonlinear optical (NLO) response can be decomposed into a nearly instantaneous bound-electronic NLR (Kerr effect), originating from the real …
Fabrication And Characterization Of Spatially-Variant Self-Collimating Photonic Crystals,
2016
University of Central Florida
Fabrication And Characterization Of Spatially-Variant Self-Collimating Photonic Crystals, Jennefir Digaum
Electronic Theses and Dissertations
Spatially-variant photonic crystals (SVPCs) created using materials having a low refractive index are shown to be capable of abruptly controlling light beams with high polarization selectivity. SVPCs are photonic crystals for which the orientation of the unit cell is controllably varied throughout the lattice to control the flow of light. Multi-photon lithography in a photo polymer was used to fabricate three-dimensional SVPCs that direct the flow of light around a 90 degree bend. The optical performance of the SVPCs was characterized using a scanning optical-fiber system that introduced light onto the input face of a structure and measured the intensity …
Laser Filament Interaction With Aerosols And Clouds,
2016
University of Central Florida
Laser Filament Interaction With Aerosols And Clouds, Cheonha Jeon
Electronic Theses and Dissertations
A high powered ultrashort laser pulse can propagate as a diffraction-free self-channeled structure called a filament, created by a combination of nonlinear processes. With its ability to convey extremely high intensity beams to distant targets, many applications such as remote sensing, cloud seeding, and discharge guiding are potentially possible. However, one of the main challenges of outdoor field applications is the laser propagation through the atmosphere where pressure fluctuations and concentrations of aerosols may be present. The rationale behind the work presented in this dissertation is to evaluate the robustness of the filamentation, measure the interaction losses as well as …
Design And Engineering Of Ultrafast Amplifier Systems,
2016
University of Central Florida
Design And Engineering Of Ultrafast Amplifier Systems, Benjamin Webb
Electronic Theses and Dissertations
Recently, the design and engineering of ultrafast laser systems have led to an extraordinary increase in laser power and performance which have brought about advances in many fields such as medicine, material processing, communications, remote sensing, spectroscopy, nonlinear optics, and atomic physics. In this work, several ultrafast amplification techniques -- including chirped-pulse amplification (CPA), optical parametric chirped-pulse amplification (OPCPA), and divided-pulse amplification (DPA) -- are described and demonstrated in the design and construction of two ultrafast laser facilities. An existing Ti:Sapphire laser system was completely redesigned with an increased power of 10 TW for experiments capable of generating hundreds of …
Broad Bandwidth Optical Frequency Combs From Low Noise, High Repetition Rate Semiconductor Mode-Locked Lasers,
2016
University of Central Florida
Broad Bandwidth Optical Frequency Combs From Low Noise, High Repetition Rate Semiconductor Mode-Locked Lasers, Anthony Klee
Electronic Theses and Dissertations
Mode-locked lasers have numerous applications in the areas of communications, spectroscopy, and frequency metrology. Harmonically mode-locked semiconductor lasers with external ring cavities offer a unique combination of benefits in that they can produce high repetition rate pulse trains with low timing jitter, achieve narrow axial mode linewidths, have the potential for entire monolithic integration on-chip, feature high wall-plug efficiency due to direct electrical pumping, and can be engineered to operate in different wavelength bands of interest. However, lasers based on InP/InGaAsP quantum well devices which operate in the important telecom C-band have thus far been relatively limited in bandwidth as …
Advanced Blue Phase Liquid Crystal Displays,
2016
University of Central Florida
Advanced Blue Phase Liquid Crystal Displays, Daming Xu
Electronic Theses and Dissertations
Thin-film transistor (TFT) liquid crystal displays (LCDs) have become indispensable in our daily lives. Their widespread applications range from smartphones, laptops, TVs to navigational devices, data projectors and wearable displays. Over past decades, massive efforts have been invested in device development, material characterization and manufacturing technology. As a result, the performance of LCDs, such as viewing angle, contrast ratio, color gamut and resolution, have been improved significantly. Nonetheless, there are still urgent needs for fast response time and low power consumption. Fast response time helps reduce motion image blurs and enable color sequential displays. The latter is particularly attractive since …
Multi-Purpose Device For Analyzing And Measuring Ultra-Short Pulses,
2016
University of Central Florida
Multi-Purpose Device For Analyzing And Measuring Ultra-Short Pulses, Naman Anilkumar Mehta
Electronic Theses and Dissertations
Intensity auto correlator is device to measure pulse widths of ultrashort pulses on the order of picoseconds and femtoseconds. I have built an in-house, compact, portable, industry standard intensity auto correlator for measuring ultrashort pulse-widths. My device is suitable for pulse-widths from 500 ps to 50 fs. The impetus for developing this instrument stemmed from our development of a multicore-fiber laser for high power laser applications, which also produces very short pulses that cannot be measured with an oscilloscope. As techniques for measuring short pulse-widths have been well studied, what made my journey exciting was the process of taking an …
Identification Of Photocurrents In Topological Insulators,
2016
West Virginia University
Identification Of Photocurrents In Topological Insulators, Derek A. Bas, Rodrigo A. Muniz, Sercan Babakiray, David Lederman, J. E. Sipe, Alan D. Bristow
Faculty & Staff Scholarship
Optical injection and detection of charge currents is an alternative to conventional transport and photoemission measurements, avoiding the necessity of invasive contact that may disturb the system being examined. This is a particular concern for analyzing the surface states of topological insulators. In this work one- and two-color sources of photocurrents are isolated and examined in epitaxial thin films of Bi2Se3. We demonstrate that optical excitation and terahertz detection simultaneously captures one- and two-color photocurrent contributions, which has not been required for other material systems. A method is devised to extract the two components, and in doing so each can …
Two-Photon Excitation Based Photochemistry And Neural Imaging,
2016
University of Texas at El Paso
Two-Photon Excitation Based Photochemistry And Neural Imaging, Kevin Andrew Hatch
Open Access Theses & Dissertations
Two-photon microscopy is a fluorescence imaging technique which provides distinct advantages in three-dimensional cellular and molecular imaging. The benefits of this technology may extend beyond imaging capabilities through exploitation of the quantum processes responsible for fluorescent events. This study utilized a two-photon microscope to investigate a synthetic photoreactive collagen peptidomimetic, which may serve as a potential material for tissue engineering using the techniques of two-photon photolysis and two-photon polymerization. The combination of these techniques could potentially be used to produce a scaffold for the vascularization of engineered three-dimensional tissues in vitro to address the current limitations of tissue engineering. Additionally, …
Shielded Radiography With A Laser-Driven Mev-Energy X-Ray Source,
2016
University of Nebraska–Lincoln
Shielded Radiography With A Laser-Driven Mev-Energy X-Ray Source, Shouyuan Chen, Grigory V. Golovin, Cameron Miller, Daniel Haden, Sudeep Banerjee, Ping Zhang, Cheng Liu, Jun Zhang, Baozhen Zhao, Shaun Clarke, Sara Pozzi, Donald Umstadter
Donald Umstadter Publications
We report the results of experimental and numerical-simulation studies of shielded radiography using narrowband MeVenergy X-rays from a compact all-laser-driven inverse-Compton-scattering X-ray light source. This recently developed Xray light source is based on a laser-wakefield accelerator with ultra-high-field gradient (GeV/cm). We demonstrate experimentally high-quality radiographic imaging (image contrast of 0.4 and signal-to-noise ratio of 2:1) of a target composed of 8-mm thick depleted uranium shielded by 80-mm thick steel, using a 6-MeV X-ray beam with a spread of 45% (FWHM) and 107 photons in a single shot. The corresponding dose of the X-ray pulse measured in front of the target …
Modification Of The Fundamental Properties Of Light Through Interaction With Nanostructured Materials,
2016
Georgia Southern University
Modification Of The Fundamental Properties Of Light Through Interaction With Nanostructured Materials, David W. Keene Ii
College of Graduate Studies: Theses & Dissertations
The field of photonics has been growing rapidly over the last few decades as it has endeavored to harness the potential of nanostructured materials to utilize the energy and momentum of electromagnetic radiation on the nanoscale. Using metal nanostructures provides the ability to take advantage of the sub-field of plasmonics which holds the promise of opening the world to vast increases in computational power by circumventing the limitations of conventional current that plague today’s processors. With a thorough understanding of this subject we also get one step closer to increasing the efficiency of solar technology, developing a finer scale of …
Evaluation Of Ray-Path Integrals In Geometrical Optics,
2016
Old Dominion University
Evaluation Of Ray-Path Integrals In Geometrical Optics, John A. Adam, Michael Pohrivchak
Mathematics & Statistics Faculty Publications
A brief summary of the physical context to this paper is provided, and the deviation angle undergone by an incident ray after k internal reflections inside a transparent unit sphere is formulated. For radially inhomogeneous spheres (in particular) this angle is related to a ray-path integral; an improper integral for which there are relatively few known exact analytical forms, even for simple refractive index profiles n(r). Thus for a linear profile the integral is a combination of incomplete elliptic integrals of the first and third kinds (though not all are as complicated as this). The ray-path integral is evaluated …
Holography In The Secondary Physics Curriculum,
2016
Eastern Illinois University
Holography In The Secondary Physics Curriculum, Stephen P. Hogan
Masters Theses
This paper presents a unit plan for effective implementation of a holography learning activity in the secondary science physics classroom. The study of holography has traditionally been limited to collegiate optics courses due to financial and physical constraints. Recent developments in the technology of holographic film has eliminated these two limiting factors. Recent secondary educators who have introduced holography with their secondary science classes have completed the activities, without much discussion or explanation regarding the scientific principles that allow the phenomenon to occur. In this paper we develop a foundational unit plan that finishes with holography as the pinnacle activity, …
Sensing Using Specialty Optical Fibers,
2016
University of Central Florida
Sensing Using Specialty Optical Fibers, Amy Van Newkirk
Electronic Theses and Dissertations
Fiber optic based sensing is a growing field with many applications in civil and aerospace engineering, oil and gas industries, and particularly in harsh environments where electronics are not able to function. Optical fibers can be easily integrated into structures, are immune to electromagnetic interference, can be interrogated from remote distances, and can be multiplexed for distributed measurements. Because of these properties, specialty fiber designs and devices are being explored for sensing temperature, strain, pressure, curvature, refractive index, and more. Here we show a detailed analysis of a multicore fiber (MCF) for sensing, including its design and optimization in simulation, …
Electrical Parasitic Bandwidth Limitations Of Oxide-Free Lithographic Vertical-Cavity Surface-Emitting Lasers,
2016
University of Central Florida
Electrical Parasitic Bandwidth Limitations Of Oxide-Free Lithographic Vertical-Cavity Surface-Emitting Lasers, Xu Yang
Electronic Theses and Dissertations
Nowadays, Vertical-Cavity Surface-Emitting Lasers (VCSELs) are the most popular optical sources in short-reach data communications. In the commercial oxide VCSEL technology, an oxide aperture is created inside resonant cavity in realizing good mode and current confinement, however, high electrical resistance comes along with forming the oxide aperture and the electrical parasitic bandwidth becomes the main limitation in modulation speed. In this report, electrical bandwidths of oxide-free lithographic VCSELs have been studied along with their general lasing properties. Due to the new ways of fabricating the aperture, record low resistances have been achieved in oxide-free lithographic VCSELs with various sizes, while …
Hybrid Integrated Photonic Platforms And Devices,
2016
University of Central Florida
Hybrid Integrated Photonic Platforms And Devices, Jeffrey Chiles
Electronic Theses and Dissertations
Integrated photonics has the potential to revolutionize optical systems by achieving drastic reductions in their size, weight and power. Remote spectroscopy, free-space communications and high-speed telecommunications are critical applications that would benefit directly from these advancements. However, many such applications require extremely wide spectral bandwidths, leading to significant challenges in their integration. The choice of integrated platform influences the optical transparency and functionality which can be ultimately achieved. In this work, several new platforms and technologies have been developed to meet these needs. First, the silicon-on-lithium-niobate (SiLN) platform is discussed, on which the first compact, integrated electro-optic modulator in the …
Monolithically Integrated Inp-Based Unidirectional Circulators Utilizing Non-Hermiticity And Nonlinearity,
2016
University of Central Florida
Monolithically Integrated Inp-Based Unidirectional Circulators Utilizing Non-Hermiticity And Nonlinearity, Parinaz Aleahmad
Electronic Theses and Dissertations
The need to integrate critical optical components on a single chip has been an ongoing quest in both optoelectronics and optical communication systems. Among the possible devices, elements supporting non-reciprocal transmission are of great interest for applications where signal routing and isolation is required. In this respect, breaking reciprocity is typically accomplished via Faraday rotation through appropriate magneto-optical arrangements. Unfortunately, standard light emitting optoelectronic materials like for example III-V semiconductors, lack magneto-optical properties and hence cannot be directly used in this capacity. To address these issues, a number of different tactics have been attempted in the last few years. These …
