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2013

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Articles 61 - 90 of 111

Full-Text Articles in Optics

Optical Down-Conversion In Doped Znse:Tb3+ Nanocrystals, Sandip Das, K. C. Mandal Feb 2013

Optical Down-Conversion In Doped Znse:Tb3+ Nanocrystals, Sandip Das, K. C. Mandal

Faculty Publications

No abstract provided.

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Imaging Stability In Force-Feedback High-Speed Atomic Force Microscopy, Byung I. Kim, Ryan Boehm Feb 2013

Imaging Stability In Force-Feedback High-Speed Atomic Force Microscopy, Byung I. Kim, Ryan Boehm

Physics Faculty Publications and Presentations

We studied the stability of force-feedback high-speed atomic force microscopy (HSAFM) by imaging soft, hard, and biological sample surfaces at various applied forces. The HSAFM images showed sudden topographic variations of streaky fringes with a negative applied force when collected on a soft hydrocarbon film grown on a grating sample, whereas they showed stable topographic features with positive applied forces. The instability of HSAFM images with the negative applied force was explained by the transition between contact and noncontact regimes in the force-distance curve. When the grating surface was cleaned, and thus hydrophilic by removing the hydrocarbon film, enhanced imaging …

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On-Chip Non-Reciprocal Optical Devices Based On Quantum Inspired Photonic Lattices, Ramy El-Ganainy, A. Eisfeld, Miguel Levy, Demetrios N. Christodoulides Jan 2013

On-Chip Non-Reciprocal Optical Devices Based On Quantum Inspired Photonic Lattices, Ramy El-Ganainy, A. Eisfeld, Miguel Levy, Demetrios N. Christodoulides

Department of Physics Publications

We propose integrated optical structures that can be used as isolators and polarization splitters based on engineered photonic lattices. Starting from optical waveguide arrays that mimic Fock space (quantum state with a well-defined particle number) representation of a non-interacting two-site Bose Hubbard Hamiltonian, we show that introducing magneto-optic nonreciprocity to these structures leads to a superior optical isolation performance. In the forward propagation direction, an input TM polarized beam experiences a perfect state transfer between the input and output waveguide channels while surface Bloch oscillations block the backward transmission between the same ports. Our analysis indicates a large isolation ratio …

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Simulation Of Charge Transport In Multi-Island Tunneling Devices: Application To Disordered One-Dimensional Systems At Low And High Biases, Madhusudan A. Savaikar, Douglas R. Banyai, Paul Bergstrom, John A. Jaszczak Jan 2013

Simulation Of Charge Transport In Multi-Island Tunneling Devices: Application To Disordered One-Dimensional Systems At Low And High Biases, Madhusudan A. Savaikar, Douglas R. Banyai, Paul Bergstrom, John A. Jaszczak

Department of Physics Publications

Although devices have been fabricated displaying interesting single-electron transport characteristics, there has been limited progress in the development of tools that can simulate such devices based on their physical geometry over a range of bias conditions up to a few volts per junction. In this work, we present the development of a multi-island transport simulator, MITS, a simulator of tunneling transport in multi-island devices that takes into account geometrical and material parameters, and can span low and high source-drain biases. First, the capabilities of MITS are demonstrated by modeling experimentaldevices described in the literature, and showing that the simulated device …

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Femtosecond Filament Interaction As A Probe For Molecular Alignment, Erik Mckee Jan 2013

Femtosecond Filament Interaction As A Probe For Molecular Alignment, Erik Mckee

Electronic Theses and Dissertations

Femtosecond laser filamentation is a highly nonlinear propagation mode. When a laser pulse propagates with a peak power exceeding a critical value Pcr (5 GW at 800 nm in air), the Kerr effect tends to collapse the beam until the intensity is high enough to ionize the medium, giving rise to plasma defocusing. A dynamic competition between these two effects takes place leaving a thin and weakly ionized plasma channel in the trail of the pulse. When an ultrafast laser pulse interacts with molecules, it will align them, spinning them about their axis of polarization. As the quantum rotational wave …

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Comparison Of Post-Detonation Combustion In Explosives Incorporating Aluminum Nanoparticles: Influence Of The Passivation Layer, William K. Lewis, C. G. Rumchik, M. J. Smith, K. A. Shiral Fernando, Christopher A. Crouse, Jonathan E. Spowart, Elena A. Guliants, Christopher E. Bunker Jan 2013

Comparison Of Post-Detonation Combustion In Explosives Incorporating Aluminum Nanoparticles: Influence Of The Passivation Layer, William K. Lewis, C. G. Rumchik, M. J. Smith, K. A. Shiral Fernando, Christopher A. Crouse, Jonathan E. Spowart, Elena A. Guliants, Christopher E. Bunker

Electrical and Computer Engineering Faculty Publications

Aluminum nanoparticles and explosive formulations that incorporate them have been a subject of ongoing interest due to the potential of aluminum particles to dramatically increase energy content relative to conventional organic explosives. We have used time-resolved atomic and molecular emission spectroscopy to monitor the combustion of aluminum nanoparticles within the overall chemical dynamicsof post-detonation fireballs. We have studied the energy release dynamics of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) charges incorporating three types of aluminum nanoparticles: commercial oxide-passivated nanoparticles, oleic acid-capped aluminum nanoparticles (AlOA), and nanoparticles in which the oxide shell of the particle has been functionalized with an acrylic monomer and copolymerized into …

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External Cavity Mode-Locked Semiconductor Lasers For The Generation Of Ultra-Low Noise Multi-Gigahertz Frequency Combs And Applications In Multi-Heterodyne Detection Of Arbitrary Optical Waveforms, Josue Davila-Rodriguez Jan 2013

External Cavity Mode-Locked Semiconductor Lasers For The Generation Of Ultra-Low Noise Multi-Gigahertz Frequency Combs And Applications In Multi-Heterodyne Detection Of Arbitrary Optical Waveforms, Josue Davila-Rodriguez

Electronic Theses and Dissertations

The construction and characterization of ultra-low noise semiconductor-based mode-locked lasers as frequency comb sources with multi-gigahertz combline-to-combline spacing is studied in this dissertation. Several different systems were built and characterized. The first of these systems includes a novel mode-locking mechanism based on phase modulation and periodic spectral filtering. This mode-locked laser design uses the same intra-cavity elements for both mode-locking and frequency stabilization to an intra-cavity, 1,000 Finesse, Fabry-Pérot Etalon (FPE). On a separate effort, a mode-locked laser based on a Slab-Coupled Optical Waveguide Amplifier (SCOWA) was built. This system generates a pulse-train with residual timing jitter of

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Metrology Of Volume Chirped Bragg Gratings Recorded In Photo-Thermo-Refractive Glass For Ultrashort Pulse Stretching And Compressing, Christopher Lantigua Jan 2013

Metrology Of Volume Chirped Bragg Gratings Recorded In Photo-Thermo-Refractive Glass For Ultrashort Pulse Stretching And Compressing, Christopher Lantigua

Electronic Theses and Dissertations

Chirped Bragg gratings (CBGs) recorded in photo-thermo-refractive (PTR) glass provide a very efficient and robust way to stretch and compress ultra-short laser pulses. These gratings offer the ability to stretch pulses from hundreds of femtoseconds, to the order of 1 ns and then recompress them. However, in order to achieve pulse stretching of this magnitude, 100 mm thick CBGs are needed. Using these CBGs to both stretch, and re-compress the pulse thus requires propagation through 200 mm of optical glass. This therefore demands perfect control of the glass homogeneity, as well as the holographic recording process of the CBG. In …

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Uv-Visible Microscope Spectrophotometric Polarization And Dichroism With Increased Discrimination Power In Forensic Analysis, Dale Kevin Purcell Jan 2013

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 …

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A Correlation-Based Optical Flowmeter For Enclosed Flows, Naiqian Zhang, Joseph S. Dvorak, Yali Zhang Jan 2013

A Correlation-Based Optical Flowmeter For Enclosed Flows, Naiqian Zhang, Joseph S. Dvorak, Yali Zhang

Biosystems and Agricultural Engineering Faculty Publications

A low-cost flowmeter would be very useful in a wide variety of monitoring situations. This article discusses the development of such a flowmeter based on optical components and its testing with water in an enclosed flow system. The sensor consisted of two sets of LEDs and phototransistors spaced 4 cm apart, monitoring the optical properties of the fluid at upstream and downstream locations, respectively. A small amount of dye was injected into the flow, which caused a change in the optical properties of the fluid at both locations. The time required for this change to move from the upstream to …

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Crystal Structure, Phase, And Optical Properties Of Yttrium-Doped Hafnium Oxide Nanocrystalline Thin Films, Alejandro Ortega Jan 2013

Crystal Structure, Phase, And Optical Properties Of Yttrium-Doped Hafnium Oxide Nanocrystalline Thin Films, Alejandro Ortega

Open Access Theses & Dissertations

Yttrium-doped hafnium oxide (YDH) nanocrystalline films were produced by sputter-deposition at various substrate times and temperatures, to produce YDH films in a wide range of thicknesses, dYDH∼25 to 1100 nm. The deposition was made onto optical grade quartz and sapphire substrates. Samples deposited on sapphire were subject to post-deposition annealing (PDA) at various times (3-24 hr) and temperatures (1100 - 1500 °C). The effect of d[special characters omitted]YDH on the crystal structure, surface/interface morphology and optical properties of YDH films was investigated. X-ray diffraction analyses revealed the formation of monoclinic phase for relatively thin films (<150nm). The evolution towards stabilized cubic phase with increasing dYDH [special characters omitted]is observed. The scanning electron microscopy results indicate the dense, columnar structure of YDH films as a function of dYDH. Spectrophotometry analyses indicate that the grown YDH films are transparent and exhibit interference fringes. The band gap was found to be ∼ 5.60 eV for monoclinic YDH films while distinct separation and an increase in band gap to 6.03 eV is evident with increasing dYDH and formation cubic YDH films. The PDA films band gaps were found to be between 5.31 and 5.72 eV, all of which exhibit secondary gaps. A correlation between growth conditions, annealing, phase evolution, and optical properties of the YDH nanocrystalline thin films is established.

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Surface Plasmon Polaritons And Waveguide Modes At Structured And Inhomogeneous Surfaces, Javier Polanco Jan 2013

Surface Plasmon Polaritons And Waveguide Modes At Structured And Inhomogeneous Surfaces, Javier Polanco

Open Access Theses & Dissertations

In chapter 1, properties of a p-polarized surface plasmon polariton are studied, propagating circumferentially around a portion of a cylindrical interface between vacuum and a metal, a situation investigated earlier by M. V. Berry (J. Phys. A: Math. Gen. 8, (1975) 1952). When the metal is convex toward the vacuum this mode is radiative and consequently is attenuated as it propagates on the cylindrical surface. An approximate analytic solution of the dispersion relation for this wave is obtained by an approach different from the one used by Berry, and plots of the real and imaginary parts of its wave number …

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Fast-Response Liquid Crystals For Photonic And Display Applications, Jie Sun Jan 2013

Fast-Response Liquid Crystals For Photonic And Display Applications, Jie Sun

Electronic Theses and Dissertations

Liquid crystal devices are attractive for many applications such as information displays, spatial light modulators and adaptive optics, because their optical properties are electrically tunable. However, response time of liquid crystal devices is a serious concern for many applications especially for those who require large phase modulation (≥2π). This is because a thick LC layer is usually needed to achieve a large phase shift while the response time of a nematic LC is highly determined by the cell gap.

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Optically Induced Forces In Scanning Probe Microscopy, Dana Kohlgraf-Owens Jan 2013

Optically Induced Forces In Scanning Probe Microscopy, Dana Kohlgraf-Owens

Electronic Theses and Dissertations

The focus of this dissertation is the study of measuring light not by energy transfer as is done with a standard photodetector such as a photographic film or charged coupled device, but rather by the forces which the light exerts on matter. In this manner we are able to replace or complement standard photodetector-based light detection techniques. One key attribute of force detection is that it permits the measurement of light over a very large range of frequencies including those which are difficult to access with standard photodetectors, such as the far IR and THz. The dissertation addresses the specific …

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High Flux Isolated Attosecond Pulse Generation, Yi Wu Jan 2013

High Flux Isolated Attosecond Pulse Generation, Yi Wu

Electronic Theses and Dissertations

This thesis outlines the high intensity tabletop attosecond extreme ultraviolet laser source at the Institute for the Frontier of Attosecond Science and Technology Laboratory. First, a unique Ti:Sapphire chirped pulse amplifier laser system that delivers 14 fs pulses with 300 mJ energy at a 10 Hz repetition rate was designed and built. The broadband spectrum extending from 700 nm to 900 nm was obtained by seeding a two stage Ti:Sapphire chirped pulse power amplifier with mJ-level white light pulses from a gas filled hollow core fiber. It is the highest energy level ever achieved by a broadband pulse in a …

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Peak Power Scaling Of Nanosecond Pulses In Thulium Based Fiber Lasers, Christian Gaida Jan 2013

Peak Power Scaling Of Nanosecond Pulses In Thulium Based Fiber Lasers, Christian Gaida

Electronic Theses and Dissertations

Thulium based fiber lasers represent a promising alternative for pulse energy scaling and high peak power generation with ytterbium based systems at 1µm. Advantages of thulium arise from the operation at longer wavelengths and a large gain bandwidth (1.8-2.1µm). Nonlinear effects, such as self phase modulation, stimulated Raman scattering and stimulated Brillouin scattering generally limit peak power scaling in fiber lasers. The longer wavelength of thulium fiber lasers and large mode field areas can significantly increase the nonlinear thresholds. Compared to 1µm systems, thulium fiber lasers enable single mode guidance for two times larger mode field diameter in step index …

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Surface Plasmonic Lens Driven Photoelectron Source For Multi-Beam Applications, Heon Joon Choi Jan 2013

Surface Plasmonic Lens Driven Photoelectron Source For Multi-Beam Applications, Heon Joon Choi

Legacy Theses & Dissertations (2009 - 2024)

Surface plasmon polariton (SPP) assisted photoelectron source array is proposed for use in distributed multiple electron beam lithography applications. Individual source is composed of a metal/dielectric surface structure with concentric circular grooves of subwavelength width surrounding a sub-wavelength aperture. Such optical power concentrators, called "plasmonic lenses", collect light incident over a broad area by converting it to surface electromagnetic waves, specifically SPP's, through diffraction by the sub-wavelength grooves surrounding the aperture. Through constructive interference of the generated SPPs between neighboring grooves, controlled by the periodicity of the grooves, high optical power densities can be achieved at the center of the …

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Mueller Based Scatterometry And Optical Characterization Of Semiconductor Materials, Gangadhara Raja Muthinti Jan 2013

Mueller Based Scatterometry And Optical Characterization Of Semiconductor Materials, Gangadhara Raja Muthinti

Legacy Theses & Dissertations (2009 - 2024)

Scatterometry is one of the most useful metrology methods for the characterization and control of critical dimensions (CD) and the detailed topography of periodic structures found in microelectronics fabrication processes. Spectroscopic ellipsometry (SE) and normal incidence reflectometry (NI) based scatterometry are the most widely used optical methodologies for metrology of these structures. Evolution of better optical hardware and faster computing capabilities led to the development of Mueller Matrix (MM) based Scatterometry (MMS). Dimensional metrology using full Mueller Matrix (16 element) scatterometry in the wavelength range of 245nm-1000nm was discussed in this work. Unlike SE and NI, MM data provides complete …

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Potential For High Resolution Microscintigraphy Using Polycapillary Optics, Patrick Richard Conlon Jan 2013

Potential For High Resolution Microscintigraphy Using Polycapillary Optics, Patrick Richard Conlon

Legacy Theses & Dissertations (2009 - 2024)

Scintigraphy, also known as nuclear imaging, is the process of imaging an object that has been labeled with a radioactive material. A novel technique employing polycapillary optics for very high - resolution scintigraphy is presented. The small channel size and angular selectivity of polycapillary optics allow them to act as multiple-hole collimators and be used with high - resolution detectors. The ability of the optics to work with high resolution detectors allow the system to discriminate against scatter, thus negating the need for energy sensitive detectors, which are known to have poor resolution. Therefore the use of polycapillary optics presents …

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Fabrication Of Two-Dimensional Nanostructures On Glass Using Nanosphere Lithography, Elmer Jim Wang Jan 2013

Fabrication Of Two-Dimensional Nanostructures On Glass Using Nanosphere Lithography, Elmer Jim Wang

Wayne State University Theses

It is desired to have artificial optical materials with controllable optical properties. Optical glass is the most common optical material for various applications. This research will attempt to create a thin layer on the substrate with controllable optical properties. The thin layer is a composite material with nanoscale features and controllable refractive index. Two-dimensional (2D) nanostructures will be created on the surface of optical glass using nanosphere lithography. In comparison with conventional techniques, this approach is more efficient and cost-effective for the creation of large areas of thin surface layers as an artificial material. A uniform monolayer of nanospheres will …

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Growth And Characterization Of Zno Based Semiconductor Materials And Devices, Ming Wei Jan 2013

Growth And Characterization Of Zno Based Semiconductor Materials And Devices, Ming Wei

Electronic Theses and Dissertations

Wide band gap semiconductors such as MgxZn1-xO represent an excellent choice for making optical photodetectors and emitters operating in the UV spectral region. High crystal and optical quality MgxZn1-xO thin films were grown epitaxially on c-plane sapphire substrates by plasma-assisted Molecular Beam Epitaxy. ZnO thin films with high crystalline quality, low defect and dislocation densities, and sub-nanometer surface roughness were achieved by applying a low temperature nucleation layer. The critical growth conditions were discussed to obtain a high quality film: the sequence of Zn and O sources for initial growth of nucleation layer, growth temperatures for both ZnO nucleation and …

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Iupac Critical Evaluation Of The Rotational-Vibrational Spectra Of Water Vapor, Part Iii: Energy Levels And Transition Wavenumbers For H216o, Jonathan Tennyson, Peter F. Bernath, Linda R. Brown, Alain Campargue, Attila G. Csaszar, Ludovic Daumont, Robert R. Gamache, Joseph T. Hodges, Olga V. Naumenko, Oleg L. Polyansky Jan 2013

Iupac Critical Evaluation Of The Rotational-Vibrational Spectra Of Water Vapor, Part Iii: Energy Levels And Transition Wavenumbers For H216o, Jonathan Tennyson, Peter F. Bernath, Linda R. Brown, Alain Campargue, Attila G. Csaszar, Ludovic Daumont, Robert R. Gamache, Joseph T. Hodges, Olga V. Naumenko, Oleg L. Polyansky

Chemistry & Biochemistry Faculty Publications

This is the third of a series of articles reporting critically evaluated rotational-vibrational line positions, transition intensities, and energy levels, with associated critically reviewed labels and uncertainties, for all the main isotopologues of water. This paper presents experimental line positions, experimental-quality energy levels, and validated labels for rotational-vibrational transitions of the most abundant isotopologue of water, H216O. The latest version of the MARVEL (Measured Active Rotational-Vibrational Energy Levels) line-inversion procedure is used to determine the rovibrational energy levels of the electronic ground state of H216O from experimentally measured lines, together with their self-consistent uncertainties, …

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Injection Locking Of Semiconductor Mode-Locked Lasers For Long-Term Stability Of Widely Tunable Frequency Combs, Charles Williams Jan 2013

Injection Locking Of Semiconductor Mode-Locked Lasers For Long-Term Stability Of Widely Tunable Frequency Combs, Charles Williams

Electronic Theses and Dissertations

Harmonically mode-locked semiconductor lasers with external ring cavities offer high repetition rate pulse trains while maintaining low optical linewidth via long cavity storage times. Single frequency injection locking generates widely-spaced and tunable frequency combs from these harmonically mode-locked lasers, while stabilizing the optical frequencies. The output is stabilized long-term with the help of a feedback loop utilizing either a novel technique based on Pound-Drever-Hall stabilization or by polarization spectroscopy. Error signals of both techniques are simulated and compared to experimentally obtained signals. Frequency combs spaced by 2.5 GHz and ~10 GHz are generated, with demonstrated optical sidemode suppression of unwanted …

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Mesoscale Light-Matter Interactions, Kyle Douglass Jan 2013

Mesoscale Light-Matter Interactions, Kyle Douglass

Electronic Theses and Dissertations

Mesoscale optical phenomena occur when light interacts with a number of different types of materials, such as biological and chemical systems and fabricated nanostructures. As a framework, mesoscale optics unifies the interpretations of the interaction of light with complex media when the outcome depends significantly upon the scale of the interaction. Most importantly, it guides the process of designing an optical sensing technique by focusing on the nature and amount of information that can be extracted from a measurement. Different aspects of mesoscale optics are addressed in this dissertation which led to the solution of a number of problems in …

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Fabrication Of Metallic Antenna Arrays Using Nanoimprint Lithography, Yu-Wei Lin Jan 2013

Fabrication Of Metallic Antenna Arrays Using Nanoimprint Lithography, Yu-Wei Lin

Electronic Theses and Dissertations

This Thesis describes the development of a cost-effective process for patterning nanoscale metal antenna arrays. Soft ultraviolet (UV) Nanoimprint Lithography (NIL) into bilayer resist was chosen since it enables repeatable large-scale replication of nanoscale patterns with good lift-off properties using a simple low-cost process. Nanofabrication often involves the use of Electron Beam Lithography (EBL) which enables the definition of nanoscale patterns on small sample regions, typically < 1 mm 2 . However its sequential nature makes the large scale production of nanostructured substrates using EBL cost-prohibitive. NIL is a pattern replication method that can reproduce nanoscale patterns in a parallel fashion, allowing the low-cost and rapid production of a large number of nanopatterned samples based on a single nanostructured master mold. Standard NIL replicates patterns by pressing a nanostructured hard mold into a soft resist layer on a substrate resulting in exposed substrate regions, followed by an optional Reactive Ion Etching (RIE) step and the subsequent deposition of e.g. metal onto the exposed substrate area. However, non-vertical sidewalls of the features in the resist layer resulting from an imperfect hard mold, from reflow of the resist layer, or from isotropic etching in the RIE step iii may cause imperfect lift-off. To overcome this problem, a bilayer resist method can be used. Using stacked resist layers with different etch rates, undercut structures can be obtained after the RIE step, allowing for easy lift-off even when using a mold with non-vertical sidewalls. Experiments were carried out using a nanostructured negative SiO2 master mold. Various material combinations and processing methods were explored. The negative master mold was transferred to a positive soft mold, leaving the original master mold unaltered. The soft mold consisted of a 5 m thick top Poly(methyl methacrylate) (PMMA), or Polyvinyl alcohol (PVA) layer, a 1.5 mm thick Polydimethylsiloxane (PDMS) buffer layer, and a glass supporting substrate. The soft mold was pressed into a bilayer of 300 nm PMMA and 350 nm of silicon based UV-curable resist that was spin-coated onto a glass slide, and cured using UV radiation. The imprinted patterns were etched using RIE, exposing the substrate, followed by metal deposition and lift-off. The experiments show that the use of soft molds enables successful pattern transfer even in the presence of small dust particles between the mold and the resist layer. Feature sizes down to 280 nm were replicated successfully

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Volume Phase Masks In Photo-Thermo-Refractive Glass, Marc Segall Jan 2013

Volume Phase Masks In Photo-Thermo-Refractive Glass, Marc Segall

Electronic Theses and Dissertations

In many applications such as beam shaping, mode conversion, and phase encoding it is necessary to alter the spatial phase profile of a beam via a phase mask. Conventional techniques to accomplish this either involve surface relief profiling in thin films such as PMMA or refractive index modulation in bulk photorefractive crystals such as lithium niobate. These materials have been used extensively for the past several decades and perform admirably in low power conditions. However, in high power systems these materials will be destroyed, requiring a new means of producing phase masks. In this dissertation a method for producing robust …

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Phase-Locking Stability Of A Quasi-Single-Cycle Pulse, Nathan Bodnar Jan 2013

Phase-Locking Stability Of A Quasi-Single-Cycle Pulse, Nathan Bodnar

Electronic Theses and Dissertations

There is increasing interest in the generation of very short laser pulses, even down to attosecond (10-18 s) durations. Laser systems with femtosecond pulse durations are needed for these applications. For many of these applications, positioning of the maximum electric field within the pulse envelope can affect the outcome. The peak of the electric field relative to the peak of the pulse is called the Carrier Envelope Phase (CEP). Controlling the position of the electric field becomes more important when pulse duration approaches single-cycle. This thesis focuses on the stabilization of a quasi-single-cycle laser facility. Improvements to this already-established laser …

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Simulation Studying Effects Of Multiple Primary Aberrations On Donut-Shaped Gaussian Beam, Chen Zhang, K. Wang, J. Bai, Y. Liu, Guiren Wang Jan 2013

Simulation Studying Effects Of Multiple Primary Aberrations On Donut-Shaped Gaussian Beam, Chen Zhang, K. Wang, J. Bai, Y. Liu, Guiren Wang

Faculty Publications

In this paper, we demonstrate the variation of donut-shaped depletion pattern which influenced by multiple primary aberrations. The simulation is base on a common stimulation emission of depletion (STED) system composed by Gaussian laser and vortex phase plate. The simulation results are helpful guidelines for analyzing the aberration of depletion patterns in real situations.

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Investigation Of Colored Dissolved Organic Matter (Cdom) Optical Properties, Nutrients, And Salinity In Coastal Florida: Springshed To Estuaries, Ana Rosa Arellano Jan 2013

Investigation Of Colored Dissolved Organic Matter (Cdom) Optical Properties, Nutrients, And Salinity In Coastal Florida: Springshed To Estuaries, Ana Rosa Arellano

USF Tampa Graduate Theses and Dissertations

Optical parameters measured via absorption spectroscopy and high-resolution fluorescence spectroscopy were used to characterize dissolved organic matter (DOM) in the springshed of Kings Bay, a spring-fed estuary located on Florida's Springs Coast. Over the past 40 years, springs supplying groundwater to Kings Bay have shown an increase in nitrate concentration. The overall goal of this project was to fingerprint wells and spring sites with elevated nitrogen concentrations using CDOM optical properties and establish relationships between nutrient and optical parameters. Samples were obtained from various sites: springs, Kings Bay surface (KBS), wells, coastal waters in and at the mouth of Crystal …

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Nonlinear Effects In Magnetic Garnet Films And Nonreciprocal Optical Bloch Oscillations In Waveguide Arrays, Pradeep Kumar Jan 2013

Nonlinear Effects In Magnetic Garnet Films And Nonreciprocal Optical Bloch Oscillations In Waveguide Arrays, Pradeep Kumar

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

This dissertation presents detailed experimental and theoretical investigations of nonlinear and nonreciprocal effects in magnetic garnet films. The dissertation thus comprises two major sections. The first section concentrates on the study of a new class of nonlinear magneto-optic thin film materials possessing strong higher order magnetic susceptibility for nonlinear optical applications. The focus was on enlarging the nonlinear performance of ferrite garnet films by strain generation and compositional gradients in the sputter-deposition growth of these films. Under this project several bismuth-substituted yttrium iron garnet (Bi,Y) 3 (Fe,Ga)5 O12(acronym as Bi:YIG) films have been sputter-deposited over gadolinium gallium …

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