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Articles 91 - 120 of 164
Full-Text Articles in Physics
Rotational And Hyperfine Analysis Of Aus, Ian A. Wyse
Rotational And Hyperfine Analysis Of Aus, Ian A. Wyse
Macalester Journal of Physics and Astronomy
Gas phase diatomic gold sulfide, AuS, was analyzed using optical spectroscopy. High-resolution spectra were collected and characterized and a global fit of the A2∑+-X2∏3/2 (0,0), B2∑–-X2∏3/2 (0,0), and C2Δ3/2-X2∏1/2 (0,0) transitions at 15570 cm-1, 16290 cm-1, and 17670 cm-1 was compiled and resulted in rotational constant determinations for the A2∑+((2σ)1(4π)4), B2∑–((2σ)2(4π)2(2σ*)1), and C2Δ3/2 …
Searching To Distinguish Defects And The Presence Of Negative Capacitance, Thaddeus Cox
Searching To Distinguish Defects And The Presence Of Negative Capacitance, Thaddeus Cox
Senior Theses
In the search for solar cells with lower manufacturing costs, thin film technology was developed. These thin films are only micrometers thick and are grown at relatively low temperatures, resulting in films with imperfections known as defects. Defects can cause thin film solar cells to have lower efficiencies than their single crystalline counterparts. In order to create more efficient thin film solar cells the physical mechanisms behind defects need to be investigated by sensitive techniques. Capacitance measurements of solar cells detect minute changes in charge in the material. For that reason, capacitance is used to electrically characterize the solar cell. …
Ultracold Trimer Ion Formation Of Rb And K, Michael Cantara
Ultracold Trimer Ion Formation Of Rb And K, Michael Cantara
University Scholar Projects
The cooling of molecules into the ultracold regime allows for high resolution laser spectroscopy that reveals their complex rotational and vibrational structure. As the temperature is lowered towards absolute zero, the kinetic energy of the particles approaches zero, and therefore the Doppler shift approaches zero. With the Doppler shift negligibly small, spectral resolution is now primarily limited by the natural linewidth of the molecular peaks. Further, ultracold temperatures make possible the production of atoms or molecules that will reside in the lowest few states of the system. The high population in a few select states provides stronger and less congested …
Thermal Neutron Analysis For Improvised Explosive Device Detection, Matthew David Marziale
Thermal Neutron Analysis For Improvised Explosive Device Detection, Matthew David Marziale
Open Access Dissertations
In this dissertation, the design of a system to detect improvised explosive devices is considered. The technique utilized is thermal neutron analysis. In this method, thermal neutrons are used to interrogate a volume for the presence of nitrogen, which is used as an indicator of explosive, given its unusual high energy line in the gamma ray spectrum generated by thermal capture reactions on explosive material. The performance of the system is then considered for a number of devices used to represent an improvised explosive device, including a 155 mm shell, an antitank mine, and a air to surface bomb. The …
Observations Of The High Vibrational Levels Of The B′′B̄ 1Σu+ State Of H2, Alexander M. Chartrand, W. Duan, R. C. Ekey, Elizabeth Mccormack
Observations Of The High Vibrational Levels Of The B′′B̄ 1Σu+ State Of H2, Alexander M. Chartrand, W. Duan, R. C. Ekey, Elizabeth Mccormack
Physics Faculty Research and Scholarship
Double-resonance laser spectroscopy via the E F 1Σg+, v'=6, J'=0-2 state was used to probe the high vibrational levels of the B"B-bar 1Σu+ state of molecular hydrogen. Resonantly-enhanced multiphoton ionization spectra were recorded by detecting ion production as a function of energy using a time of flight mass spectrometer. New measurements of energies for the v=51-66 levels for the B"B-bar state of H2 are reported, which, taken with previous results, span the v=46-69 vibrational levels. Results for energy levels are compared to theoretical close-coupled calculations [L. Wolniewicz, T. …
The Virtual Atomic And Molecular Data Centre (Vamdc) Consortium, Marie-Lise Dubernet, B. K. Antony, Ernesto Quintas-Sánchez, For Full List Of Authors, See Publisher's Website.
The Virtual Atomic And Molecular Data Centre (Vamdc) Consortium, Marie-Lise Dubernet, B. K. Antony, Ernesto Quintas-Sánchez, For Full List Of Authors, See Publisher's Website.
Chemistry Faculty Research & Creative Works
The Virtual Atomic and Molecular Data Centre (VAMDC) Consortium is a worldwide consortium which federates atomic and molecular databases through an e-science infrastructure and an organisation to support this activity. About 90% of the inter-connected databases handle data that are used for the interpretation of astronomical spectra and for modelling in many fields of astrophysics. Recently the VAMDC Consortium has connected databases from the radiation damage and the plasma communities, as well as promoting the publication of data from Indian institutes. This paper describes how the VAMDC Consortium is organised for the optimal distribution of atomic and molecular data for …
Identification Of Photocurrents In Topological Insulators, Derek A. Bas, Rodrigo A. Muniz, Sercan Babakiray, David Lederman, J. E. Sipe, Alan D. Bristow
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 …
Terahertz Spectroscopic Breath Analysis As A Viable Analytical Chemical Sensing Technique, Robert M. Schueler
Terahertz Spectroscopic Breath Analysis As A Viable Analytical Chemical Sensing Technique, Robert M. Schueler
Browse all Theses and Dissertations
The ability to quantify trace chemicals in human breath enables the possibility of identifying breath biomarkers to aid in diagnosis. The vast majority of the studies in the analytical breath analysis rely on GC-MS techniques for quantification of the human breath composition1,2,3,4. THz spectroscopy of breath is rapid, sensitive, and highly specific molecular identification in complex mixtures containing 10-100 analytes with near `absolute' specificity. THz spectroscopic breath analyzers require chemical preconcentration. A newly developed custom preconcentrator was constructed and compared in its performance to a commercial system. Unlike the commercial counterpart, the new system does not require cryogenic liquids, is …
Depth-Resolved Multispectral Sub-Surface Imaging Using Multifunctional Upconversion Phosphors With Paramagnetic Properties, Zaven Ovanesyan, L. Christopher Mimun, Gangadharan Ajith Kumar, Brian G. Yust, Chamath Dannongoda, Karen S. Martirosyan, Dhiraj K. Sardar
Depth-Resolved Multispectral Sub-Surface Imaging Using Multifunctional Upconversion Phosphors With Paramagnetic Properties, Zaven Ovanesyan, L. Christopher Mimun, Gangadharan Ajith Kumar, Brian G. Yust, Chamath Dannongoda, Karen S. Martirosyan, Dhiraj K. Sardar
Physics & Astronomy Faculty Publications
Molecular imaging is very promising technique used for surgical guidance, which requires advancements related to properties of imaging agents and subsequent data retrieval methods from measured multispectral images. In this article, an upconversion material is introduced for subsurface near-infrared imaging and for the depth recovery of the material embedded below the biological tissue. The results confirm significant correlation between the analytical depth estimate of the material under the tissue and the measured ratio of emitted light from the material at two different wavelengths. Experiments with biological tissue samples demonstrate depth resolved imaging using the rare earth doped multifunctional phosphors. In …
Low Intensity Gamma-Ray Spectroscopy Of The Lake Labyrinth Meteorite, Tristan C. Paul
Low Intensity Gamma-Ray Spectroscopy Of The Lake Labyrinth Meteorite, Tristan C. Paul
Physics
A 23.7g fragment of the Lake Labyrinth Meteorite (fell in 1924, collected in 1934 at Lake Labyrinth in South Australia, Australia) was re-investigated for evidence of the presence of 98Tc using a two dimensional low-intensity gamma-ray spectrometer. A new calibration technique using 26Al sources found the gamma-rays previously thought to be due to 98Tc are more likely from 166Ho. The presence of 166Ho is most likely due to activation of the stable 165Ho in the meteorite from terrestrial background sources where it was stored.
Improved Terahertz Modulation Using Germanium Telluride (Gete) Chalcogenide Thin Films, Alexander H. Gwin, Christopher H. Kodama, Tod V. Laurvick, Ronald Coutu Jr., Philip F. Taday
Improved Terahertz Modulation Using Germanium Telluride (Gete) Chalcogenide Thin Films, Alexander H. Gwin, Christopher H. Kodama, Tod V. Laurvick, Ronald Coutu Jr., Philip F. Taday
Faculty Publications
We demonstrate improved terahertz (THz) modulation using thermally crystallized germanium telluride (GeTe) thin films. GeTe is a chalcogenide material that exhibits a nonvolatile, amorphous to crystalline phase change at approximately 200 °C, as well as six orders of magnitude decreased electrical resistivity. In this study, amorphous GeTe thin films were sputtered on sapphire substrates and then tested using THz time-domain spectroscopy (THz-TDS). The test samples, heated in-situ while collecting THz-TDS measurements, exhibited a gradual absorbance increase, an abrupt nonvolatile reduction at the transition temperature, followed by another gradual increase in absorbance. The transition temperature was verified by conducting similar thermal …
Coupling Nuclear Induced Phonon Propagation With Conversion Electron Mössbauer Spectroscopy, Michael J. Parker
Coupling Nuclear Induced Phonon Propagation With Conversion Electron Mössbauer Spectroscopy, Michael J. Parker
Theses and Dissertations
Mössbauer spectroscopy is a very sensitive measurement technique (10-8 eV) which prompted motivation for the experiment described in this thesis. Namely, can a sensitive detection system be developed to detect nuclear recoils on the order of 10 to 100 of eVs? The hypothesis that this thesis tests is: Nuclear induced phonon bursts caused by Rutherford scattered alphas, decayed from 241Am, in a type-310 stainless steel material can couple with 7.3 keV conversion electron Mössbauer events at the other end of the material which will have a statistically significant effect on a Mössbauer spectrum. The phonon bursts produced by …
Measuring The Hyperfine Splittings Of Lowest Energy Atomic Transitions In Rubidium, Benjamin D. Graber
Measuring The Hyperfine Splittings Of Lowest Energy Atomic Transitions In Rubidium, Benjamin D. Graber
Undergraduate Honors Thesis Projects
The goal of this experiment was to measure the hyperfine energy splittings of the ground to first excited state transitions in rubidium using saturated absorption spectroscopy. Using this technique, we measured these transition energy spectra by taking the difference of two photodiode outputs due to multiple beams of a single laser scanned over a range of frequencies and shone through a cell of Rb vapor. When the laser frequency was resonant with an atomic transition, photons of those frequencies were absorbed, leaving a dip in intensity of the beam measured at the photodiode. One of the two laser beams had …
A Two-Laser Beam Technique For Improving The Sensitivity Of Low Frequency Open Path Tunable Diode Laser Absorption Spectrometer (Op-Tdlas) Measurements, Isra'a Lateef Mohammad
A Two-Laser Beam Technique For Improving The Sensitivity Of Low Frequency Open Path Tunable Diode Laser Absorption Spectrometer (Op-Tdlas) Measurements, Isra'a Lateef Mohammad
Theses and Dissertations
Open path tunable diode-laser absorption spectroscopy (OP-TDLAS) is a promising technique that is proposed for detecting low concentrations of possible biogenic gases on Mars. This technique determines the concentration of a gas by measuring the amount of laser light absorbed by molecules at a specific wavelength that is characteristic of those molecules. One of the major factors limiting sensitivity in the OP-TDLAS systems is noise. At low modulation frequencies, 1/f noise usually dominates. This 1/f noise is minimized in many spectroscopy systems by use of high frequency techniques. However, these methods use complex instruments that include reference cells and other …
Mueller Matrix Spectroscopic Ellipsometry Of Multiferroics, Roman Basistyy
Mueller Matrix Spectroscopic Ellipsometry Of Multiferroics, Roman Basistyy
Dissertations
Multiferroics, materials which possess several ferroic orders, are the focus of research in recent years. Among these materials are oxide crystals, such as, for example, RMnO3, RMn2O5, R3Fe5O12, where R stands for rare earth ions. The most fascinating physics occurs when magnon-lattice coupling reveals itself in the far-IR spectra of multiferroics. The expected optical behavior puts multiferroics into a more general category of bi-anisotropic materials, the properties of which could be only described using anisotropic dielectric ε(ω), magnetic μ(ω), and …
Pulsed Inductive Plasma Studies By Spectroscopy And Internal Probe Methods, Warner C. Meeks
Pulsed Inductive Plasma Studies By Spectroscopy And Internal Probe Methods, Warner C. Meeks
Doctoral Dissertations
The broad effort of the Missouri Plasmoid Experiment is to elucidate the energy conversion processes in a pulsed inductive discharge due to the presence of plasma. The test article is a 440 to 490 kHz theta-pinch (or solenoidal) geometry coil with a stored energy of around 80 joules. In this work experimental hydrogen, helium, argon and xenon data at back-fill pressures of 10 to 100 mTorr (1.3 to 133.3 Pa) are obtained and interpreted. Spectral and internal probe studies were performed on MPX Mk.I and Mk.II devices, respectively. IR spectra were acquired in the Mk.I device for argon and xenon. …
First Measurement Of The Polarization Observable E In The P→ (Ɣ→, Π+) In Reaction Up To 2.25 Gev, S. Strauch, W. J. Briscoe, M. Döring, E. Klempt, V. A. Nikonov, E. Pasyuk, D. Rönchen, A.V. Sarantsev, I. Strakovsky, R. Workman, K. P. Adhikari, D. Adikaram, L. El Fassi
First Measurement Of The Polarization Observable E In The P→ (Ɣ→, Π+) In Reaction Up To 2.25 Gev, S. Strauch, W. J. Briscoe, M. Döring, E. Klempt, V. A. Nikonov, E. Pasyuk, D. Rönchen, A.V. Sarantsev, I. Strakovsky, R. Workman, K. P. Adhikari, D. Adikaram, L. El Fassi
Physics Faculty Publications
First results from the longitudinally polarized frozen-spin target (FROST) program are reported. The double-polarization observable E, for the reaction ɣ→p→→π+n, has been measured using a circularly polarized tagged-photon beam, with energies from 0.35 to 2.37 GeV. The final-state pions were detected with the CEBAF Large Acceptance Spectrometer in Hall B at the Thomas Jefferson National Accelerator Facility. These polarization data agree fairly well with previous partial-wave analyses at low photon energies. Over much of the covered energy range, however, significant deviations are observed, particularly in the high-energy region where high-L multipoles contribute. The data have been …
Wavelength Dependent Specific Plasmon Resonance Coupling Of Single Silver Nanoparticles With Egfp, Kerry J. Lee, Tao Huang, Prakash D. Nallathamby
Wavelength Dependent Specific Plasmon Resonance Coupling Of Single Silver Nanoparticles With Egfp, Kerry J. Lee, Tao Huang, Prakash D. Nallathamby
Chemistry & Biochemistry Faculty Publications
Noble metal nanoparticles (NPs) possess unique plasmonic properties, enabling them to serve as sub-diffraction light sources and nano-antennae for a wide range of applications. Here we report the specific interaction of single Ag NPs with single EGFP molecules and a high dependence of their interaction upon localized-surface-plasmon-resonance (LSPR) spectra of single Ag NPs and EGFP. The LSPR spectra of single red Ag NPs show a stunning 60 nm blue-shift during their incubation with EGFP, whereas they remain unchanged during their incubation with bovine serum albumin (BSA). Interestingly, the peak wavelengths of the LSPR spectra of green and blue Ag NPs …
Synchrotron Based Infrared Microspectroscopy Of Carbonaceous Chondrites., Mehmet Yesiltas
Synchrotron Based Infrared Microspectroscopy Of Carbonaceous Chondrites., Mehmet Yesiltas
Electronic Theses and Dissertations
Relationships between organic molecules and inorganic minerals are investigated in five carbonaceous chondrites, Northwest Africa 852 (CR2), Tagish Lake (C2-ungroupped), Orgueil (CI1), Sutter's Mill (CM), and Murchison (CM2), with micron spatial resolution using synchrotron-based imaging micro-FTIR spectroscopy. Correlations based on absorption strength for various constituents are determined using statistical correlation analysis. Silicate band is found to be positively correlated with stretching modes of aliphatic hydrocarbons in NWA 852 and Tagish Lake. The former is highly correlated with the hydration band in all meteorites. Negative correlation is observed between water+organics and carbonate bands in all meteorites. Two dimensional infrared maps for …
Optical Spectroscopy Of Xenon-Related Defects In Diamond, Yury Dziashko
Optical Spectroscopy Of Xenon-Related Defects In Diamond, Yury Dziashko
Dissertations, Theses, and Capstone Projects
The work presents the results of optical studies of Xe-related defect in diamond. This defect is one of a few having narrow zero-phonon line in the near-infrared part of the photo-luminescence spectra. It appears in diamond after Xe+ ion implantation followed by thermal annealing. Given unique physical properties of diamond (hardness, optical transparency in wide spectral range, chemical inertness, high thermal conductivity, low thermal expansion coefficient) and stability of Xe-related center it can be viewed as an potential candidate for the source of single-photons, or as optically manipulated qubit, not unlike nitrogen-vacancy center. However, compared to the latter Xe-related center …
Optimization Of Plasmon Decay Through Scattering And Hot Electron Transfer, Drew Dejarnette
Optimization Of Plasmon Decay Through Scattering And Hot Electron Transfer, Drew Dejarnette
Graduate Theses and Dissertations
Light incident on metal nanoparticles induce localized surface oscillations of conductive electrons, called plasmons, which is a means to control and manipulate light. Excited plasmons decay as either thermal energy as absorbed phonons or electromagnetic energy as scattered photons. An additional decay pathway for plasmons can exist for gold nanoparticles situated on graphene. Excited plasmons can decay directly to the graphene as through hot electron transfer. This dissertation begins by computational analysis of plasmon resonance energy and bandwidth as a function of particle size, shape, and dielectric environment in addition to diffractive coupled in lattices creating a Fano resonance. With …
In-Package Atmospheric Pressure Cold Plasma Treatment Of Cherry Tomatoes, N. Misra, Kevin Keener, Paula Bourke, J Mosnier, Patrick J. Cullen
In-Package Atmospheric Pressure Cold Plasma Treatment Of Cherry Tomatoes, N. Misra, Kevin Keener, Paula Bourke, J Mosnier, Patrick J. Cullen
Articles
Cold plasma is increasingly under research for decontamination of foods, especially fresh fruits and vegetables. The effect of cold plasma on food quality, however, remains under researched. This study investigates the effects of cold plasma generated within a sealed package from a dielectric barrier discharge on the physical quality parameters and respiration rates of cherry tomatoes. Respiration rates and weight loss were monitored continuously, while other parameters are reported at the end of storage period. Differences among weight loss, pH and firmness for control and treated cherry tomatoes were insignificant towards the end of storage life. Changes in respiration rates …
Steady-State Switching And Dispersion/Absorption Spectroscopy Of Multistate Atoms Inside An Optical Ring Cavity, Jiteng Sheng
Steady-State Switching And Dispersion/Absorption Spectroscopy Of Multistate Atoms Inside An Optical Ring Cavity, Jiteng Sheng
Graduate Theses and Dissertations
This thesis mainly focuses on the experimental investigations of electromagnetically induced transparency (EIT) related phenomena in various systems involving multilevel atoms inside an optical ring cavity. Semiclassical methods, e.g. density-matrix equations, are used through out this thesis to simulate the experimental results. First, the cavity transmission spectrum can be significantly modified when multilevel atoms are placed inside an optical ring cavity. Such coupled atom-cavity systems are well explained by the intracavity dispersion/absorption properties. Specifically, three-level lambda-type, four-level N-type and double-lambda-type atoms inside an optical ring cavity are investigated by examining their cavity transmission spectra. Second, optical multistability (OM) has been …
Iron Abundances And Atmospheric Parameters Of Red Giants In The Open Cluster Ic 4756, Julie Djordjevic
Iron Abundances And Atmospheric Parameters Of Red Giants In The Open Cluster Ic 4756, Julie Djordjevic
All Theses
Three red giants were investigated within the open cluster IC 4756 using observations taken from the McDonald Observatory's 2.1m Otto Struve Telescope and the Sandiford Cassegrain Echelle Spectrometer (SES). Iron abundances were calculated for each star based on the equivalent widths of Fe I and Fe II lines measured using the line lists of Bubar and King (2010) and Schuler et al. (2005). Also derived were the basic atmospheric parameters: effective temperature, surface gravity, metallicity, and microturbulence. Her 35, Her 85, and Her 249 were found to have corresponding [Fe I/H] of 0.06 ± 0.04, -0.16 ± 0.03, and -0.16 …
A Spectroscopic Investigation Of Excited States Of The Nucleus 73br, Brigid Esposito
A Spectroscopic Investigation Of Excited States Of The Nucleus 73br, Brigid Esposito
College of Science and Health Theses and Dissertations
Gamma rays emitted in the de-excitation of the nucleus 73Br were created in two distinct experiments. Using Gammasphere and Microball, the first experiment selected nuclei created in the reaction for an incident 40Ca beam and a 40Ca target that were coincident with the creation of 1 a particle, 3 protons, and 4 gamma rays. These results were analyzed using a gating procedure that allowed for the validation of published level schemes and the identification of new rotational bands in the level scheme. Using Gammasphere, the Fragment Mass Analyzer, an ionization chamber, and neutron detectors, the second experiment …
Uv-Visible Microscope Spectrophotometric Polarization And Dichroism With Increased Discrimination Power In Forensic Analysis, Dale Kevin Purcell
Uv-Visible Microscope Spectrophotometric Polarization And Dichroism With Increased Discrimination Power In Forensic Analysis, Dale Kevin Purcell
All Open Access Legacy Dissertations and Capstone Projects
Microanalysis of transfer (Trace) evidence is the application of a microscope and microscopical techniques for the collection, observation, documentation, examination, identification, and discrimination of micrometer sized particles or domains. Microscope spectrophotometry is the union of microscopy and spectroscopy for microanalysis. Analytical microspectroscopy is the science of studying the emission, reflection, transmission, and absorption of electromagnetic radiation to determine the structure or chemical composition of microscopic-size materials. Microscope spectrophotometry instrument designs have evolved from monochromatic illumination which transmitted through the microscope and sample and then is detected by a photometer detector (photomultiplier tube) to systems in which broad-band (white light) illumination …
Doppler-Free Saturated Fluorescence Spectroscopy Of Lithium Using A Stabilized Frequency Comb, Michael E. Rowan
Doppler-Free Saturated Fluorescence Spectroscopy Of Lithium Using A Stabilized Frequency Comb, Michael E. Rowan
Honors Papers
The lineshapes of the D1 (22S1/2 → 22P1/2 ) and D2 (22S3/2 → 22P1/2) transitions in lithium were measured using a diode laser that was frequency-stabilized to a Ti:Sapphire 1 GHz optical frequency comb. The excitation was achieved by retroreflecting the diode laser, in effect producing the Doppler-free profiles for the center frequencies of transitions. The observed spectra were compared to density matrix calculations to gain insight into systematic effects including the dependence of Doppler-free profiles on power and polarization angle of the diode. For certain transitions, the method of saturated fluorescence spectroscopy inevitably leads to the presence of extra …
Spatial And Spectral Performance Of A Chromotomosynthetic Hyperspectral Imaging System, Randall L. Bostick, Glen P. Perram
Spatial And Spectral Performance Of A Chromotomosynthetic Hyperspectral Imaging System, Randall L. Bostick, Glen P. Perram
Faculty Publications
The spatial and spectral resolutions achievable by a prototype rotating prism chromotomosynthetic imaging (CTI) system operating in the visible spectrum are described. The instrument creates hyperspectral imagery by collecting a set of 2D images with each spectrally projected at a different rotation angle of the prism. Mathematical reconstruction techniques that have been well tested in the field of medical physics are used to reconstruct the data to produce the 3D hyperspectral image. The instrument operates with a 100 mm focusing lens in the spectral range of 400–900 nm with a field of view of 71.6 mrad and angular resolution of …
Random Transformations Of Optical Fields And Applications, Thomas Kohlgraf-Owens
Random Transformations Of Optical Fields And Applications, Thomas Kohlgraf-Owens
Electronic Theses and Dissertations
The interaction of optical waves with material systems often results in complex, seemingly random fields. Because the fluctuations of such fields are typically difficult to analyze, they are regarded as noise to be suppressed. Nevertheless, in many cases the fluctuations of the field result from a linear and deterministic, albeit complicated, interaction between the optical field and the scattering system. As a result, linear systems theory (LST) can be used to frame the scattering problem and highlight situations in which useful information can be extracted from the fluctuations of the scattered field. Three fundamental problems can be posed in LST …
Characterization And Application Of Isolated Attosecond Pulses, Michael Chini
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 …