Optics Commons^™

Mathematical Analysis Of Continuum Electrodynamics: Implications For The Kinetic Formulation Of Light, Cheyenne Jack Sheppard

Student Theses and Dissertations

Optical momentum within material media has been studied for a century. Although great strides have been made towards understanding photon momenta, there is still a question regarding the correct momentum of light. This is due to the many mathematical interpretations of Maxwell's unification of electromagnetism, yielding many independent views of classical electrodynamic quantities. Within this correspondence, the optical momentum controversy is studied via mathematical principles of continuum relativistic electrodynamics. The electromagnetic wave momentum is studied via moving contribution, where a framework for moving media is developed. Application of the framework with respect to independent formulations of electrodynamics are shown to …

Modeling The Optical Response To A Near-Field Probe Tip From A Generalized Multilayer Thin Film, A.J. Lawrence

Dissertations and Theses

The contrast mechanism in Kerr imaging is the apparent angle through which the plane of polarization is rotated upon reflection from a magnetic surface. This can be calculated for a well characterized surface given the polarization state of the incident light. As in traditional optical microscopy, the spatial resolution is limited by diffraction to roughly half the wavelength of the illumination light.

The diffraction limit can be circumvented through the use of near-field scanning optical microscopy, in which the illumination source is an evanescent field at the tip of a tapered optical fiber. A novel probe design for near-field optical …

Study Of Laser Speckle Scattering In Vitreous Humor Models, Wanseok Oh

Graduate Theses - Physics and Optical Engineering

When a highly high coherent light propagates through a medium, interactions between light and the medium produces a unique intensity speckle pattern that is dependent on several factors such as particle size in the medium, wavelength of the light, concentration of medium, and scattering angle. Speckle patterns from either static or dynamic specimens have been studied using optical techniques due to its non-invasive nature. Speckle patterns from biological specimens (dynamic) are different from that of the static specimens since random movement of molecules (Brownian motion) in the biological specimen affect the light interactions and thereby the intensity of the speckles …

Optical Bistability With Two Serially Integrated Inp-Soas On A Chip, Michael Edward Plascak

Graduate Theses - Physics and Optical Engineering

A photonic switch using two series-connected, reverse-biased semiconductor optical amplifiers integrated onto a single device has been proposed and switching operation has been verified experimentally. The switching operates on two principles; an electrical bistability arising from the connection of two p-i-n structures in series, and the quantum confined Stark effect in reverse-biased multiple quantum well structures. The result is an electroabsorption modulation of the light through the SOAs due to the alternating voltage states. The system simultaneously produces outputs with both inverted and non-inverted hysteresis behavior, with experimental switching speeds demonstrated up to 400 kHz for a reverse-bias voltage of …

Segmentation Of Pulmonary Nodules In Computed Tomography Using A Regression Neural Network Approach And Its Application To The Lung Image Database Consortium And Image Database Resource Initiative Dataset, Temesguen Messay, Russell C. Hardie, Timothy R. Tuinstra

Electrical and Computer Engineering Faculty Publications

We present new pulmonary nodule segmentation algorithms for computed tomography (CT). These include a fully-automated (FA) system, a semi-automated (SA) system, and a hybrid system. Like most traditional systems, the new FA system requires only a single user-supplied cue point. On the other hand, the SA system represents a new algorithm class requiring 8 user-supplied control points. This does increase the burden on the user, but we show that the resulting system is highly robust and can handle a variety of challenging cases. The proposed hybrid system starts with the FA system.

If improved segmentation results are needed, the SA …

Segmentation Of Pulmonary Nodules In Computed Tomography Using A Regression Neural Network Approach And Its Application To The Lung Image Database Consortium And Image Database Resource Initiative Dataset, Temesguen Messay, Russell C. Hardie, Timothy R. Tuinstra

Electrical and Computer Engineering Faculty Publications

We present new pulmonary nodule segmentation algorithms for computed tomography (CT). These include a fully-automated (FA) system, a semi-automated (SA) system, and a hybrid system. Like most traditional systems, the new FA system requires only a single user-supplied cue point. On the other hand, the SA system represents a new algorithm class requiring 8 user-supplied control points. This does increase the burden on the user, but we show that the resulting system is highly robust and can handle a variety of challenging cases. The proposed hybrid system starts with the FA system. If improved segmentation results are needed, the SA …

Multivariate Statistical Methodologies Applied In Biomedical Raman Spectroscopy: Assessing The Validity Of Partial Least Squares Regression Using Simulated Model Datasets., Mark Keating

Articles

Raman spectroscopy is fast becoming a valuable analytical tool in a number of biomedical scenarios, most notably disease diagnostics. Importantly, the technique has also shown increasing promise in the assessment of drug interactions on a cellular and subcellular level, particularly when coupled with multivariate statistical analysis. However, an important consideration, both with Raman spectroscopy and the associated statistical methodologies, is the accuracy of these techniques and more specifically the sensitivities which can be achieved and ultimately the limits of detection of the various methods. The purpose of this study is thus the construction of a model simulated data set with …

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 …

Volume Component Analysis For Classification Of Lidar Data, Nina M. Varney, Vijayan K. Asari

Electrical and Computer Engineering Faculty Publications

One of the most difficult challenges of working with LiDAR data is the large amount of data points that are produced. Analysing these large data sets is an extremely time consuming process. For this reason, automatic perception of LiDAR scenes is a growing area of research. Currently, most LiDAR feature extraction relies on geometrical features specific to the point cloud of interest. These geometrical features are scene-specific, and often rely on the scale and orientation of the object for classification. This paper proposes a robust method for reduced dimensionality feature extraction of 3D objects using a volume component analysis (VCA) …

A Robust Fringe-Adjusted Joint Transform Correlator For Efficient Object Detection, Paheding Sidike, Vijayan K. Asari, Mohammad S. Alam

Electrical and Computer Engineering Faculty Publications

The fringe-adjusted joint transform correlation (FJTC) technique has been widely used for real-time optical pattern recognition applications. However, the classical FJTC technique suffers from target distortions due to noise, scale, rotation and illumination variations of the targets in input scenes. Several improvements of the FJTC have been proposed in the literature to accommodate these problems. Some popular techniques such as synthetic discriminant function (SDF) based FJTC was designed to alleviate the problems of scale and rotation variations of the target, whereas wavelet based FJTC has been found to yield better performance for noisy targets in the input scenes. While these …

Tailoring Optical Complex Fields With Nano-Metallic Surfaces, Guanghao Rui, Qiwen Zhan

Electro-Optics and Photonics Faculty Publications

Recently there is an increasing interest in complex optical fields with spatially inhomogeneous state of polarizations and optical singularities. Novel effects and phenomena have been predicted and observed for light beams with these unconventional states. Nanostructured metallic thin film offers unique opportunities to generate, manipulate and detect these novel fields. Strong interactions between nano-metallic surfaces and complex optical fields enable the development of highly compact and versatile functional devices and systems. In this review, we first briefly summarize the recent developments in complex optical fields. Various nano-metallic surface designs that can produce and manipulate complex optical fields with tailored characteristics …

Computational Optical Imaging: Applications In Synthetic Aperture Imaging, Phase Retrieval, And Digital Holography, Dennis Joseph Lee

Open Access Dissertations

Computational imaging has become an important field, as a merger of both algorithms and physical experiments. In the realm of microscopy and optical imaging, an important application is the problem of improving resolution, which is bounded by wavelength and numerical aperture according to the classic diffraction limit. We will investigate the resolution enhancement of phase objects such as transparent biological cells. One key challenge is how to measure phase experimentally. Standard interferometric techniques have the drawback of being sensitive to environmental vibrations and temperature fluctuations, and they use a reference arm which requires more space and cost. Non-holographic methods provide …

Quantitative Mrna Detection With Advanced Nonlinear Microscopy, Jing Liu

Open Access Dissertations

Cell-specific information on quantity and localization of key mRNA transcripts in single-cell level are critical to the assessment of cancer risk, therapy efficacy, and effective prevention strategies. While current techniques are not capable to visualize single mRNA transcript beyond the diffraction limit. In this thesis, two nonlinear technologies, second harmonic super-resolution microscopy (SHaSM) and transient absorption microscopy (TAM), are developed to detect and quantify single Human edimer receptor 2 (Her2) mRNA transcripts. The SHaSM is used to detect single mRNA transcript beyond the diffraction limit, while the TAM is employed to detect mRNA without the interference of fluorescence background. The …

Circular Bessel Field Statistics And The Pursuit Of Far-Subwavelength Resolution, Yulu Chen

Open Access Dissertations

The statistical description of wave propagation in random media is important for many applications. While polarized light in systems with weakly interacting scatterers and sufficient overall scatter has zero-mean circular Gaussian statistics, the underlying assumptions break down in the Anderson localization and weakly scattering regimes. Although probability density functions for wave intensity and amplitude exist beyond Gaussian statistics, suitable statistical descriptions for the field with strong and weak random scatter were unknown. The first analytical probability density function for the field that is effective in both the Anderson localization regime and the weakly scattering regime is derived by modeling the …

Coherent Thermal Emission From Photonic Nanostructures Composed Of Ta, W, Ge, And Hfo2 Thin Films, Mark T. Dodd

Theses and Dissertations

Combining an understanding of thin films and structure/property relationships, photonic nano-structures were developed in order to affect the spectral and directional radiative properties of coherent thermal emission. The targeted emission range was 2-20 µm. Structures with appropriate materials in order to achieve thermal stability were designed and tested. Implementing a Finite Difference Time Domain numerical method, four truncated multilayer resonators were designed to selectively emit at certain transmissive wavelength bands of the atmosphere in 2-20 µm. Ellipsometric measurements and models were used in order to extract the optical constants of thin layers of materials chosen for the resonator designs. These …

Photon Sieve Bandwidth Broadening By Reduction Of Chromatic Aberration Effects Using Second-Stage Diffractive Optics, Christopher M. Tulip

Theses and Dissertations

A photon sieve is a lightweight diffractive optic which can be useful for space-based imaging applications. It is limited by chromatic aberration and a narrow bandwidth. A Fresnel zone plate is used to counteract this effect in a manner similar to that accomplished with a traditional holographic corrector. First, a radiometric analysis established a target for bandwidth improvement. Next, a sieve was designed, fabricated, and characterized. Third, the bandwidth-broadening correction scheme was developed to correct primary chromatic aberration. Finally, a zone plate was designed, fabricated, and tested. Performance of the corrected system was measured over the target bandwidth. The corrected …

Modifications To A Cavity Ringdown Spectrometer To Improve Data Acquisition Rates, Gregory Alan Bostrom

Dissertations and Theses

Cavity ringdown spectroscopy (CRDS) makes use of light retention in an optical cavity to enhance the sensitivity to absorption or extinction of light from a sample inside the cavity. When light entering the cavity is stopped, the output is an exponential decay with a decay constant that can be used to determine the quantity of the analyte if the extinction or absorption coefficient is known. The precision of the CRDS is dependent on the rate at which the system it acquires and processes ringdowns, assuming randomly distributed errors. We have demonstrated a CRDS system with a ringdown acquisition rate of …

Investigation Of Electromagnetic Velocities And Negative Refraction In A Chiral Metamaterial With Second-Order Material Dispersion Using Spectral Analyses And Dispersive Models, Monish Ranjan Chatterjee, Tarig A. Algadey

Electrical and Computer Engineering Faculty Publications

In recent years, considerable research has been carried out relative to the electromagnetic (EM) propagation and refraction characteristics in metamaterials with emphasis on the origins of negative refractive index.

Negative refractive index may be introduced in metamaterials via different methods; one such is the condition whereby the Poynting vector of the EM wave is in opposition to the group velocity in the material. Alternatively, negative refractive index also occurs when the group and phase velocities in the medium are in opposition. The latter phenomenon has been extensively investigated in the literature, including recent work involving chiral metamaterials with material dispersion …

Discrete Excitation Spectrum Of A Classical Harmonic Oscillator In Zero-Point Radiation, Wayne Cheng-Wei Huang, Herman Batelaan

Department of Physics and Astronomy: Faculty Publications

We report that upon excitation by a single pulse, a classical harmonic oscillator immersed in the classical electromagnetic zero-point radiation exhibits a discrete harmonic spectrum in agreement with that of its quantum counterpart. This result is interesting in view of the fact that the vacuum field is needed in the classical calculation to obtain the agreement.

Optimization-Free Optical Focal Field Engineering Through Reversing The Radiation Pattern From A Uniform Line Source, Yanzhong Yu, Qiwen Zhan

Electro-Optics and Photonics Faculty Publications

A simple and flexible method is presented for the generation of optical focal field with prescribed characteristics. By reversing the field pattern radiated from a uniform line source, for which the electric current is constant along its extent, situated at the focus of a 4Pi focusing system formed by two confocal high-NA objective lenses, the required illumination distribution at the pupil plane for creating optical focal field with desired properties can be obtained. Numerical example shows that an arbitrary length optical needle with extremely high longitudinal polarization purity and consistent transverse size of ~0.36λ over the entire depth of focus …

Simulation Of Light Scattering From Brownian Particles, Raymond Mullen

Physics

This project is a computational exploration of the light scattering from Brownian particles. We simulate laser light scattering to produce fluctuating light intensity at a detector located in the far-field. By analyzing the statistical properties of this intensity fluctuation, and knowing physical parameters of the system, we can deduce the size of the scattering particles. The computer simulation is in excellent agreement with theory.

Demonstrating Continuous Variable Einstein–Podolsky–Rosen Steering In Spite Of Finite Experimental Capabilities Using Fano Steering Bounds, James Schneeloch, Samuel H. Knarr, Gregory A. Howland, John C. Howell

Mathematics, Physics, and Computer Science Faculty Articles and Research

We show how one can demonstrate continuous-variable Einstein–Podolsky–Rosen (EPR) steering without needing to characterize entire measurement probability distributions. To do this, we develop a modified Fano inequality useful for discrete measurements of continuous variables and use it to bound the conditional uncertainties in continuous-variable entropic EPR-steering inequalities. With these bounds, we show how one can hedge against experimental limitations including a finite detector size, dead space between pixels, and any such factors that impose an incomplete sampling of the true measurement probability distribution. Furthermore, we use experimental data from the position and momentum statistics of entangled photon pairs in parametric …

Coherent Digital Holographic Adaptive Optics, Changgeng Liu

USF Tampa Graduate Theses and Dissertations

A new type of adaptive optics (AO) based on the principles of digital holography (DH) is proposed and developed for the use in wide-field and confocal retinal imaging. Digital holographic adaptive optics (DHAO) dispenses with the wavefront sensor and wavefront corrector of the conventional AO system. DH is an emergent imaging technology that gives direct numerical access to the phase of the optical field, thus allowing precise control and manipulation of the optical field. Incorporation of DH in an ophthalmic imaging system can lead to versatile imaging capabilities at substantially reduced complexity and cost of the instrument. A typical conventional …

Tunable Narrow Band Difference Frequency Thz Wave Generation In Dast Via Dual Seed Ppln Opg, Brian Dolasinski, Peter E. Powers, Joseph W. Haus, Adam Cooney

Electro-Optics and Photonics Faculty Publications

We report a widely tunable narrowband terahertz (THz) source via difference frequency generation (DFG). A narrowband THz source uses the output of dual seeded periodically poled lithium niobate (PPLN) optical parametric generators (OPG) combined in the nonlinear crystal 4-dimthylamino-N-methyl-4-stilbazolium-tosylate (DAST). We demonstrate a seamlessly tunable THZ output that tunes from 1.5 THz to 27 THz with a minimum bandwidth of 3.1 GHz. The effects of dispersive phase matching, two-photon absorption, and polarization were examined and compared to a power emission model that consisted of the current accepted parameters of DAST.

Secure Transmission Of Static And Dynamic Images Via Chaotic Encryption In Acousto-Optic Hybrid Feedback With Profiled Light Beams, Monish Ranjan Chatterjee, Fares S. Almehmadi

Electrical and Computer Engineering Faculty Publications

Secure information encryption via acousto-optic (AO) chaos with profiled optical beams indicates substantially better performance in terms of system robustness. This paper examines encryption of static and time-varying (video) images onto AO chaotic carriers using Gaussian-profile beams with diffracted data numerically generated using transfer functions. The use of profiled beams leads to considerable improvement in the encrypted signal.

While static image encryption exhibits parameter tolerances within about ±10% for uniform optical beams, profiled beams reduce the tolerance to less than 1%, thereby vastly improving both the overall security of the transmitted information as well as the quality of the image …

Multiple Object Detection In Hyperspectral Imagery Using Spectral Fringe-Adjusted Joint Transform Correlator, Paheding Sidike, Vijayan K. Asari, Mohammad S. Alam

Electrical and Computer Engineering Faculty Publications

Hyperspectral imaging (HSI) sensors provide plenty of spectral information to uniquely identify materials by their reflectance spectra, and this information has been effectively used for object detection and identification applications. Joint transform correlation (JTC) based object detection techniques in HSI have been proposed in the literatures, such as spectral fringe-adjusted joint transform correlation (SFJTC) and with its several improvements.

However, to our knowledge, the SFJTC based techniques were designed to detect only similar patterns in hyperspectral data cube and not for dissimilar patterns. Thus, in this paper, a new deterministic object detection approach using SFJTC is proposed to perform multiple …

Two-Dimensional Temperature Analysis Of Nuclear Fireballs Using Digitized Film, Robert C. Slaughter, Tyler R. Peery, John W. Mcclory

Faculty Publications

Researchers at Lawrence Livermore National Laboratory have begun digitizing technical films spanning the atmospheric nuclear testing operations conducted by the United States from 1945 through 1962. Each atmospheric nuclear test was filmed by Edgerton, Germeshausen, and Grier, Inc., using between 20 to 40 cameras per test. These technical film test data represent a primary source for advancing the knowledge of nuclear weapon output as well as the understanding of nonnuclear high-temperature gases. This manuscript outlines the procedures followed in order to perform two-dimensional temperature calculations for early time nuclear fireballs using digitized film. The digitized optical densities of the film …

Macular Pigment Spatial Distribution Effects On Glare Disability, Christopher Putnam, Carl Bassi

College of Optometry Faculty Works

Purpose This project explored the relationship of the macular pigment optical density (MPOD) spatial profile with measures of glare disability (GD) across the macula. Results The cHFP identified reliable MPOD spatial distribution maps demonstrating a 1st-order exponential decay as a function of increasing eccentricity. There was a significant negative correlation between both measures of foveal MPOD and GD using 6cycles per degree (cpd) and 9cpd stimuli. Significant correlations were found between corresponding parafoveal MPOD measures and GD at 2 and 4° of eccentricity using 9cpd stimuli with greater MPOD associated with less glare disability. Conclusions These results are consistent with …

Geometry Induced Magneto-Optic Effects In Lpe Grown Magnetic Garnet Films, Ashim Chakravarty

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

This dissertation addresses dimensionality-induced magneto-optic effects in liquid-phaseepitaxy magnetic garnet thin films. It is found that the Faraday rotation (FR) per unit length evinces a marked and steady enhancement as the film thickness is reduced below ~100 nm in Bi_0.8Gd_0.2Lu₂Fe₅O₁₂, although it remains constant in the micron- and most of the submicron- regime. The reported specific FR change in such reduced dimensions is due to sizedependent modifications in diamagnetic transition processes in the garnet film. These processes correspond to the electronic transitions from the singlet ⁶S ground state to …

Role Of Antenna Modes And Field Enhancement In Second Harmonic Generation From Dipole Nanoantennas, Domenico De Ceglia, Maria Antonietta Vincenti, Costantino De Angelis, Andrea Locatelli, Joseph W. Haus, Michael Scalora

Electro-Optics and Photonics Faculty Publications

We study optical second harmonic generation from metallic dipole antennas with narrow gaps. Enhancement of the fundamental-frequency field in the gap region plays a marginal role on conversion efficiency. In the symmetric configuration, i.e., with the gap located at the center of the antenna axis, reducing gap size induces a significant red-shift of the maximum conversion efficiency peak. Either enhancement or inhibition of second-harmonic emission may be observed as gap size is decreased, depending on the antenna mode excited at the harmonic frequency. The second-harmonic signal is extremely sensitive to the asymmetry introduced by gap’s displacements with respect to the …