Physical Sciences and Mathematics Commons^™

Filaments And Their Application To Air Lasing, Spectroscopy, And Guided Discharge, Ali Rastegari

Optical Science and Engineering ETDs

Laser filamentation is a fascinating phenomenon that occurs when an intense laser beam travels through transparent materials, in particular air. At sufficiently high power (TW in the near IR, GW in the UV), instead of spreading out like a regular laser beam, something remarkable happens: the laser beam becomes tightly focused, creating a thin and intense column of light called a laser filament. Laser filamentation is characterized by two main properties: (I) a high-intensity core that remains narrow over long distances beyond the Rayleigh range and (II) a low-density plasma channel within the core. In recent years, laser filamentation has …

Photonic Monitoring Of Atmospheric Fauna, Adrien P. Genoud

Dissertations

Insects play a quintessential role in the Earth’s ecosystems and their recent decline in abundance and diversity is alarming. Monitoring their population is paramount to understand the causes of their decline, as well as to guide and evaluate the efficiency of conservation policies. Monitoring populations of flying insects is generally done using physical traps, but this method requires long and expensive laboratory analysis where each insect must be identified by qualified personnel. Lack of reliable data on insect populations is now considered a significant issue in the field of entomology, often referred to as a “data crisis” in the field. …

Display Applications For Grating Angle Magnification Accelerated Angular Scanners, Daniel Jesus Valdes

UNLV Theses, Dissertations, Professional Papers, and Capstones

This work includes experimental demonstrations of grating angle magnification accelerated optical beam scanners. Diffraction grating scanners governed by the grating equation can have scan speed advantages over the flat mirror bound by Snell's law of reflection. Scan speed enhancement of 750% was achieved with a 635nm laser and 1800 groove/mm diffraction grating configuration thanks to the grating angle magnification. A three-color diffraction grating scanner shows identical results at larger scan angles. Tunable acceleration speed is a feature enabled by the diffraction grating scanner to operate in a high-speed scanning region and/or high-resolution scanning region depending on the demands of the …

Investigation Of Laser And Nonlinear Properties Of Anderson Localizing Optical Fibers, Cody Ryan Bassett

Optical Science and Engineering ETDs

In this dissertation, I investigate the possibility of lasing and nonlinear phenomena in completely solid-state transverse Anderson localizing optical fibers (TALOFs). I examine three areas within this range of topics. The research in nonlinear phenomena focuses on four-wave mixing (FWM). FWM is of high interest in TALOFs due to the fact that guided localized modes of the fiber each have different propagation constants, and thus unique possible FWM pairs can be generated from the same input pump beam. I demonstrate the generation of FWM in the TALOF by pumping it with 532 nm light into a localized mode and observing …

Collective Behavior Of Dissipatively-Coupled Photonic Oscillator Networks, Jiajie Ding

Dissertations, Theses, and Capstone Projects

This thesis discusses the collective behavior of networks formed by photonic oscillators. The key motivations for doing this research are the interest in developing high power laser arrays on photonic chips and performing optical computing.

Plasma-Laser Wakefield Acceleration, Jonathan Babu

Physics

Many texts detailing the derivations and science of Wakefield Acceleration are aimed at graduate and doctorate level scholars, and these may seem intimidating to new physics students. This paper is meant to be an introduction to the nature of plasmas, lasers, laser-plasma interactions, and Laser Wakefield Acceleration (LWFA), with sources given where extra detail may be required. I recognize that this paper is not meant to be an all-encompassing review on the nature of the topics, as these topics are complex and subject of entire textbooks. Instead, I aim to provide an introduction to these topics to a college-level scholar …

Sigesn Light-Emitting Devices: From Optical To Electrical Injection, Yiyin Zhou

Graduate Theses and Dissertations

Si photonics is a fast-developing technology that impacts many applications such as data centers, 5G, Lidar, and biological/chemical sensing. One of the merits of Si photonics is to integrate electronic and photonic components on a single chip to form a complex functional system that features compact, low-cost, high-performance, and reliability. Among all building blocks, the monolithic integration of lasers on Si encountered substantial challenges. Si and Ge, conventional epitaxial material on Si, are incompetent for light emission due to the indirect bandgap. The current solution compromises the hybrid integration of III-V lasers, which requires growing on separate smaller size substrates …

Mutual Interaction Induced Multi-Particle Physics In Qed Systems – Cooperative Spontaneous Emission And Photonic Dimer Enhanced Two-Photon Excitation, Yao Zhou

McKelvey School of Engineering Theses & Dissertations

In recent years, the study of quantum electrodynamics (QED) in light-matter interactions has discovered various interesting phenomenons that orient many applications. However, due to the ambient entanglement among photons and atoms, few-particle dynamics remains challenging to analyze precisely and limits the progress in several fields. In few-particle systems, different number of atoms interacting with the light field generates drastically different results, even when there is only a single photon involved in the system. The interference between individual atom’s spontaneous emission wavefunctions can cooperatively alter the effective atom-light coupling strength. Depending on the spatial distance between individual of atoms and the …

Tailored Frequency Comb Structures And Their Sensing Applications, James Hendrie

Optical Science and Engineering ETDs

The focus of this dissertation is the development and investigation of nested cavity mode-locked lasers and their resultant tailored frequency combs. A nested cavity is made up of two cavities, known as parents. One parent is a larger, active, 100MHz Ti:Saph oscillator and the other is a smaller, passive, 7GHz Fabry-Perot Etalon (FPE). Unlike standard frequency combs that are continuous, a tailored comb’s teeth are distributed in equally spaced groups where the center of each group corresponds to the resonance of the FPE and the side bands are determined by the resonances of the Ti:Saph. This unique coupling of the …

Optical Response Analysis Of Thz Photoconductive Antenna Using Comsol Multiphysics, Jose Isaac Santos Batista

Electrical Engineering Undergraduate Honors Theses

A THz photoconductive antenna consists of antenna pads laid over a photoconductive substrate. These types of antennas are excited through the application of an optical pump (laser), which generates carriers inside the semiconductor. The acceleration and recombination of these carriers produce photocurrent that excites the antenna and generates THz pulse. This thesis focuses on analyzing the optical response of a photoconductive antenna, which consist of the interaction of the incident electric field of a laser pump with the radiating device. It develops the amplitude modulation process of a plane wave of light into a laser pump. It also takes into …

Optimization Of An Injection Locked Laser System For Cold Neutral Atom Traps, Elliot M. Lehman

Physics

Many types of quantum systems are being explored for use in quantum computers. One type of quantum system that shows promise for quantum computing is trapped neutral atoms. They have long coherence times, since they have multiple stable ground states and have minimal coupling with other atoms and their environment, and they can be trapped in arrays, making them individu- ally addressable. Once trapped, they can be initialized and operated on using laser pulses. This experiment utilizes a pinhole diffraction pattern, which can trap atoms in both bright and dark areas. To maximize trap strength, an injection-locked laser amplification system …

Study Of Blinking Statistics In Silver Coated Cobalt Ferrite Single Nanoprticle Using Two-Photon Fluorescence Microscopy, Rajen Kumar Goutam

Open Access Theses & Dissertations

Two-photon fluorescence microscopy is a powerful tool to study the molecular and cellular interactions. This technology is a non-invasive approach with the advantage of three-dimensional imaging up to submicron resolution. Two-photon excitation process is the result of simultaneous absorption of two photons that has special features of reduced photodamaged and elongated penetration depth on samples. In this work, blinking statistics of silver-coated Cobalt ferrite (CoFe2O4) single nanocrystal is studied using two-photon fluorescence microscopy. By defining the intensity threshold, the observed fluorescence is divided into two distinct stages: OFF and ON states. Both of these states followed the inverse power law. …

Developing A Femtosecond Stimulated Raman Spectroscopy Experiment For Solid State Materials, Daniel Hammerland

Electronic Theses and Dissertations

Femtosecond Stimulated Raman Spectroscopy (FSRS) is a ultrafast spectroscopy technique first implemented by chemists to understand isomerization and other ultrafast molecular morphology changes by resolving vibrational dynamics[1, 2, 3]. FSRS has an unparalleled temporal and spectral resolution [4, 1, 5, 6] that arises as a result of a clever combination of picosecond and femtosecond pulses. However, despite this capability, FSRS has yet to be applied to modern materials in condensed matter physics. This thesis explores the design and implementation of FSRS to study two-dimensional materials in order to measure their quantum confined vibrational dynamics on utlrafast time scales.

Diffraction Of Laguerre Gaussian Vortex Beams, Anindya Ambuj

Graduate Theses and Dissertations

The natural phenomenon of waves bending around obstacles is diffraction. Spatial characteristics of the diffraction pattern depends on the incident wave field, the shape, and size of the aperture. The diffraction of a plane wave of light by a slit and a circular aperture produce the sinc-squared and the Airy intensity patterns, respectively. On the contrary, the diffraction of Laguerre-Gauss vortex (LGV) beams by simple apertures such as a slit, circular apertures, and polygons show many unexpected features.

LGV beams have ρ ` e i`φ transverse spatial dependence, where ρ is the distance from the beam axis, φ the azimuthal …

Development Of A Compact Broadband Optical Parametric Oscillator For Ultra-Sensitive Molecular Detection, Sean O. Crystal

Honors Undergraduate Theses

Every gas molecule has a unique absorption spectrum that can be captured using optical spectroscopy to identify an unknown sample's composition. Frequency combs systems can provide an extremely broad mid-infrared spectrum that is very useful for molecular detection. A degenerate optical parametric oscillator (OPO) was built to generate the down-converted and shifted frequency comb spectrum. This system utilizes an ultra-short pulse 1.56µm pump laser and a never before used orientation patterned gallium-phosphide crystal. Periodically polled lithium niobate (PPLN), Gallium Arsenide (GaAs) and Gallium Phosphide are all crystals used to accomplish this task. GaP, in comparison to PPLN, has (i) a …

Cavity Ringdown Spectroscopy In Nitrogen/Oxygen Mixtures In The Presence Of Alpha Radiation, Sidney John Gautrau

Master's Theses

This research was part of an effort to experimentally validate computational models under development for radiation-induced atmospheric effects. Cavity Ringdown Spectroscopy (CRDS) was used to measure the concentration of chemical products generated as a result of radiation interactions in a controlled atmosphere. Experiments were conducted in a vacuum chamber interfaced with a gas introduction system that controlled the initial atmospheric composition. A quadrupole mass spectrometer and tunable dye laser were integrated to confirm initial atmospheric composition, and provide wavelength flexibility for detecting a variety of chemical products generated by radiation interactions. CRDS measurements were made for ozone production resulting from …

Transmission Of Focused Picosecond Light Pulse Through Multimode Fibers, Yin Cen

Dissertations, Theses, and Capstone Projects

This thesis focuses on a technique of delivering spatially focused and temporally compressed picosecond laser pulses through multimode fibers. This study was inspired by recent success in focusing light through optically diffusive media of which multimode fibers were a special case in terms of causing scrambled phase distribution in the transmitted light. The approach involved controlling the phase distribution of incoming beam using a deformable mirror prior to its entry into the multimode fiber in order to achieve constructive interference at selected spots in the output. With phase control, the intensity of the focused light at the output can be …

Coherent Beam Combining Of Ultrashort Laser Pulses, Ahmad Azim

Honors Undergraduate Theses

Ultrashort pulsed lasers have become critical to understanding light-matter interactions in new regimes such as generation of attosecond pulses, laser filamentation, and intense relativistic processes. Development of more powerful and energetic ultrafast lasers is required for advancing these fields of study. Several petawatt class systems now exist with more in development to further scale peak power and extend the frontier of ultrafast laser technology. Another relevant solution to the scaling of energy and power of ultrashort pulses is coherent beam combining (CBC). CBC is useful for not only scaling of laser parameters but also to mitigate parasitic nonlinear processes associated …

Increasing The Sensitivity Of The Michelson Interferometer Through Multiple Reflection, Woonghee Youn

Graduate Theses - Physics and Optical Engineering

Michelson interferometry has been one of the most famous and popular optical interference system for analyzing optical components and measuring optical metrology properties. Typical Michelson interferometer can measure object displacement with wavefront shapes to one half of the laser wavelength. As testing components and devices size reduce to micro and nano dimension, Michelson interferometer sensitivity is not suitable. The purpose of this study is to design and develop the Michelson interferometer using the concept of multiple reflections. This thesis proposes a new and novel design for a multiple reflection interferometer, where the number of reflections does not affect the quality …

Barium Concentrations In Rock Salt By Laser Induced Breakdown Spectroscopy, Kiley J. Spirito

Dissertations, Master's Theses and Master's Reports - Open

Time-REsolved Laser Induced Breakdown Spectroscopy (TRELIBS) was used to determine the elemental concentration of barium in Texas Dome rock salt. TRELIBS allows for an efficient and in situ concentration analysis technique that detects a wide range of elements with no sample preparation.

TRELIBS measurements were made in the 545nm to 594nm wavelength range. The proximity of a strong barium emission line (553.5481 nm) to the sodium doublet (588.9950 nm and 589.5924 nm) allowed for measurement within a single frame of the spectrograph.

This barium emission line was compared to the sodium doublet for relative intensity. A homemade calibration sample containing …

Construction And Optimization Of A Tapered Amplifier System For Applications In Ultra-Cold Plasma Research, Ryan Cole

Honors Theses

The number density of cold atoms confined in a magneto-optical trap (MOT) is critically dependent on the intensity of the lasers used to cool the sample. To generate large optical powers while retaining the practicality of homemade external cavity diode lasers (ECDLs), a tapered amplifier (TA) system was designed and constructed to amplify the output of an existing 780 nm, continuous-wave ECDL. The amplifier’s performance is discussed in terms of its gain and power output. Under standard operating conditions, optical amplification of 12 dB is achieved, with a maximum power output of 0.75 W. The completed amplifier is installed into …

Laser-Induced Breakdown Spectroscopy For Analysis Of High Density Methane-Oxygen Mixtures, Matthew Dackman

Masters Theses

The applicability of laser-induced breakdown spectroscopy (LIBS) toward greater than atmospheric density combustion diagnostics is examined. Specifically, this involves ascertaining the feasibility of measuring chemical equivalence ratios directly from atomic emission spectra at high density. The need for such measurement arises from the desire to quantify real time, localized combustion performance in weakly mixed flows. Insufficiently mixed flows generally result in unwanted byproducts, possess the propensity for overall combustion instability, and are increasingly likely to experience localized flame extinction.

We simulate methane/oxygen combustion in ambient pressures ranging 1 to 4 atmospheres, demonstrating these results to be analogous to what would …

Integration Of Instrumentation And Processing Software Of A Laser Speckle Contrast Imaging System, Jacob James Carrick

Dissertations, Master's Theses and Master's Reports - Open

Laser speckle contrast imaging (LSCI) has the potential to be a powerful tool in medicine, but more research in the field is required so it can be used properly. To help in the progression of Michigan Tech's research in the field, a graphical user interface (GUI) was designed in Matlab to control the instrumentation of the experiments as well as process the raw speckle images into contrast images while they are being acquired. The design of the system was successful and is currently being used by Michigan Tech's Biomedical Engineering department. This thesis describes the development of the LSCI GUI …

The Talbot Effect, Malia Kawamura

Honors Theses

The goal of this project is to experimentally investigate the optical Talbot effect and the electron Talbot effect. The Talbot effect is a near-field diffraction effect which occurs when plane waves are incident upon a grating. The Talbot effect creates full grating revivals at integral Talbot lengths and revivals with greater spatial periodicity at fractional Talbot lengths. We use a green helium neon laser and Ronchi rulings to take CCD camera images of the fractional Talbot revivals directly. Additionally, a photodiode records light intensity as a function of time as a second identical grating is moved to verify the presence …

Forcing Mutual Coherence In Diode Laser Stacks, Jonathan R. Wurtz

Honors Theses and Capstones

This paper will discuss both theoretical and experimental attempts to improve the spatial beam quality of diode laser stacks using an external optical system. An overview and derivation of the mathematics of both the optical system and diode lasers will be discussed. The experimental setup will be presented, as well as the fundamental theoretical and experimental results that suggest the external optical system used for this thesis fails to improve the beam quality of a diode laser stack.

Design And Construction Of An Optical Tweezers, Pavel Aprelev

Honors Theses

We constructed an optical tweezers apparatus, used it to trap transparent micron-sized particles, and moved those particles within a sample by moving the sample relative to the focal point of the trapping beam. The optical trap was based on the fact that focused coherent light creates forces on dielectric objects that point towards the focal point. The magnitude and the span of the force are dependent on the size of the focal point of the beam - generally around 1µm - and the intensity of light. We used an 808 nm 200 mW laser and a piezoelectric stage to trap …

Properties Of High Energy Laser Light Transmission Through Large Core Optical Cables, Christopher Kennedy

Electronic Theses and Dissertations

Laser induced damage is of interest in studying the transmission of large amounts of optical energy through step-index, large core multimode fibers. Optical fibers often have to be routed around objects when laser light is being transmitted between two locations which require the fiber to bend into a curve. Depending on how tight the bend is, this can result in transmission losses or even catastrophic damage when the energy density of the laser pulse exceeds the damage threshold of silica glass. The purpose of this study is to: Establish a minimum bend radius that would allow high energy (GW/cm2 ) …

Dynamic Feedback Pulse Shaping For High Power Chirped Pulse Amplification System, Dat Nguyen

Electronic Theses and Dissertations

The topic of this proposal is the development of high peak power laser sources with a focus on linearly chirped pulse laser sources. In the past decade chirped optical pulses have found a plethora of applications such as photonic analog-to-digital conversion, optical coherence tomography, laser ranging, etc. This dissertation analyzes the aforementioned applications of linearly chirped pulses and their technical requirements, as well as the performance of previously demonstrated parabolic pulse shaping approaches. The experimental research addresses the topic of parabolic pulse generation in two distinct ways. First, pulse shaping technique involving a time domain approach is presented, that results …

Building And Characterization Of Laser Diodes As Well As System Design Of A Dual Wavelength Fabry-Perot Interferometer, Nicholas Czapla

Physics

No abstract provided.

Characterization And Application Of Isolated Attosecond Pulses, Michael Chini

Electronic Theses and Dissertations

Tracking and controlling the dynamic evolution of matter under the influence of external fields is among the most fundamental goals of physics. In the microcosm, the motion of electrons follows the laws of quantum mechanics and evolves on the timescale set by the atomic unit of time, 24 attoseconds. While only a few time-dependent quantum mechanical systems can be solved theoretically, recent advances in the generation, characterization, and application of isolated attosecond pulses and few-cycle femtosecond lasers have given experimentalists the necessary tools for dynamic measurements on these systems. However, pioneering studies in attosecond science have so far been limited …