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Articles 1 - 30 of 114

Full-Text Articles in Engineering

Validation Of Machine Vision And Action Sport Cameras For 3d Motion Analysis Model Reconstruction, John David Johnson, Michael Hales, Randy Emert Nov 2023

Validation Of Machine Vision And Action Sport Cameras For 3d Motion Analysis Model Reconstruction, John David Johnson, Michael Hales, Randy Emert

Faculty and Research Publications

The study investigated the feasibility of using action sport cameras for motion analysis research. Data acquired from two different marker-based motion capture systems and six different camera combinations were analyzed for motion reconstruction accuracy. Two different calibration procedures were used to determine the influence on marker position reconstruction. Static and dynamic calibration mean merit score differences between the reference and experimental camera systems were 0.4 mm and 1.3 mm, respectively. Angular displacement difference between the reference and experimental camera systems range between 0.1 and 2.0 degrees. A systematic bias (− 0.54 to 0.19 degrees) was determined between the reference and …


Quantitative, Photocurrent Multidimensional Coherent Spectroscopy, Adam Halaoui Nov 2023

Quantitative, Photocurrent Multidimensional Coherent Spectroscopy, Adam Halaoui

Electronic Theses and Dissertations

Multidimensional coherent spectroscopy (MDCS) is a quickly growing field that has a lot of advantages over more conventional forms of spectroscopy. These advantages all come from the fact that MDCS allows us to get time resolved correlated emission and absorption spectra using very precisely chosen interactions between the density matrix and the excitation laser. MDCS spectra gives the researcher a lot of information that can be extracted purely through qualitative analysis. This is possible because state couplings are entirely separated on the spectra, and once we know how to read the data, we can see how carriers transport in the …


Tunable Linear And Nonlinear Metasurfaces Based On Hybrid Gold-Graphene Plasmons, Matthew Feinstein Sep 2023

Tunable Linear And Nonlinear Metasurfaces Based On Hybrid Gold-Graphene Plasmons, Matthew Feinstein

Dissertations, Theses, and Capstone Projects

Optical Metasurfaces are planar structures that are patterned with subwavelength structures and are very thin compared to the wavelength of light. Despite their thinness, these structured materials can strongly interact with incident light to effect the functionalities of conventional optical components, such as rotation of the polarization state, beam steering, lensing, spectral filtering, and holography, to name a few. Metasurfaces can also facilitate nonlinear optical effects, such as the mixing of beams at different frequencies to generate a beam at a new frequency.

The ability to alter the behavior of a metasurface during operation is highly desired for applications such …


Photophoretic Optical Trapping, Essa Ababseh Jun 2023

Photophoretic Optical Trapping, Essa Ababseh

Electrical Engineering

Photophoretic Optical Trapping (POT) is a relatively new concept in the field of optics which has potential application in 3D display. The POT is realized by confining a particle within a very small location of the optical system, mostly around the focus. The particle, if captured by the beam, has the potential to print visible 3D images in free space. Our POT system is encapsulated by an acrylic enclosure, which also incorporates a biconvex lens as well as an adjustable focus laser module. Particles are released around the top of the lens’ focal point until the captured particle can be …


Light Sheet Microscopy Incubation Design And Control Scheme, Venkatanathan Kidambi May 2023

Light Sheet Microscopy Incubation Design And Control Scheme, Venkatanathan Kidambi

Honors Scholar Theses

The focus of the following paper is the development of a light sheet or selective plane illumination microscopy (LSM / SPIM) platform to support long duration three dimensional imaging of various cells and tissues. This paper describes the complete design and fabrication process behind the prototype, including a definition of light sheet microscopy and its differences from confocal microscopy, as well as existing open source selective plane microscopy literature and designs. The complete engineering design process as applied to the microscope design is described in detail. Specifically, this paper will focus on the development of an incubation chamber for light …


Optical Control System For Atmospheric Turbulence Mitigation, Martyn Lemon Dec 2022

Optical Control System For Atmospheric Turbulence Mitigation, Martyn Lemon

All Theses

Propagation of laser light is distorted in the presence of atmospheric turbulence. This poses an issue for sensing, free-space optical communications, and transmission of power. With an ever-increasing demand for high-speed data communications, particularly between satellites, unmanned vehicles, and other systems that benefit from a point-to-point link, this issue is critical for the field. A variety of methods have been proposed to circumvent this issue. Some major categories include the manipulation of the light’s structure, an adaptive scheme at the optical receiver, scanning mirror systems, or a transmission of simultaneous signals with a goal to improve robustness.

There is an …


Investigation Of Laser And Nonlinear Properties Of Anderson Localizing Optical Fibers, Cody Ryan Bassett Nov 2022

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 …


Maximum Trapping Focal Length In Photophoretic Trap For 3d Imaging Systems, Jason M. Childers Jun 2022

Maximum Trapping Focal Length In Photophoretic Trap For 3d Imaging Systems, Jason M. Childers

Electrical Engineering

This product is a photophoretic trapping system which allows varying focal lengths to test which focal lengths are possible for trapping toner particles. This system establishes that there exists a maximum trapping distance limitation and is the first time the effect of focal length is studied in a photophoretic trapping system. Increasing photophoretic trapping focal length is necessary for improving this technology as a 3D display. The 3D imaging technology is realized by dragging a microscopic (micrometer-scale) particles with a laser beam to trace an image. This technology can display fully colored and high-resolution 3D images visible from almost any …


Novel 360-Degree Camera, Ian Gauger, Andrew Kurtz, Zakariya Niazi Apr 2022

Novel 360-Degree Camera, Ian Gauger, Andrew Kurtz, Zakariya Niazi

Frameless

Circle Optics is developing novel technology for low-parallax, real time, panoramic image capture using an integrated array of multiple adjacent polygonal-edged cameras. This technology can be optimized and deployed for a variety of markets, including cinematic VR. Circle Optics’ existing prototype, Hydra Alpha, will be demonstrated.


Enhanced Study Of Complex Systems By Unveiling Hidden Symmetries With Dynamical Visibility, Nhat Vu Minh Nguyen Jan 2022

Enhanced Study Of Complex Systems By Unveiling Hidden Symmetries With Dynamical Visibility, Nhat Vu Minh Nguyen

2022 Symposium

One of the great challenges in complex and chaotic dynamics is to reveal its deterministic structures. These temporal dynamical structures are sometimes a consequence of hidden symmetries. Detecting and understanding them can allow the study of complex systems even without knowing the full underlying mathematical description of the system. Here we introduce a new technique, called Dynamical Visibility, that quantifies temporal correlations of the dynamics based upon some symmetry conditions. This visibility measures the departure of the dynamics from internal symmetries. We apply this technique to well-known chaotic systems, such as the logistic map and the circle map, as well …


The Aquatic Particle Number Quandry, Alexander B. Bochdansky, Huanqing Huang, Maureen H. Conte Jan 2022

The Aquatic Particle Number Quandry, Alexander B. Bochdansky, Huanqing Huang, Maureen H. Conte

OES Faculty Publications

Optical surveys of aquatic particles and their particle size spectra have become important tools in studies of light propagation in water, classification of water masses, and the dynamics of trophic interactions affecting particle aggregation and flux. Here, we demonstrate that typical settings used in image analysis vastly underestimate particle numbers due to the particle – gel continuum. Applying a wide range of threshold values to change the sensitivity of our detection system, we show that macrogels cannot be separated from more dense particles, and that a true particle number per volume cannot be ascertained; only relative numbers in relation to …


Further Exploration Of Optical/Thermal Interaction Effects On High-Power Laser System Performance And Optimization Through Multiphysics System-Level Modeling, Nathaniel J. Butt Jan 2022

Further Exploration Of Optical/Thermal Interaction Effects On High-Power Laser System Performance And Optimization Through Multiphysics System-Level Modeling, Nathaniel J. Butt

Browse all Theses and Dissertations

High-power laser systems (HPLS) have wide-ranging applications in many prominent areas. HPLS use laser diodes to pump fiber gain media. Understanding the functionality of both components is critical for achieving effective HPLS operation. System optical efficiency is a function of diode junction temperature. As junction temperature changes, the wavelength spectrum of the diode output shifts causing optical power losses in the fiber gain media. Optical/thermal interactions of the dynamically coupled laser diodes and fiber gain media are not fully understood. A system level modeling approach considering the interactions between optical performance and component temperature is necessary. Four distinct models were …


Fabricating Nanophotonic Devices Using Nanofabrication Techniques, Scott Cummings Dec 2021

Fabricating Nanophotonic Devices Using Nanofabrication Techniques, Scott Cummings

Student Scholar Symposium Abstracts and Posters

Nanofabrication processes are widely used to make the integrated circuits and computer chips that are ubiquitous in today’s technology. These fabrication processes can also be applied to the creation of nanophotonic devices. The ways in which we apply these fabrication techniques in the field of photonics is often constrained by the technologies used for electronics manufacturing which presents an interesting engineering challenge. These limitations include availability and cost of certain fabrication equipment and techniques required to create state-of-the-art nanophotonic devices. Through work with the University of California Irvine nano-fabrication cleanroom, we designed and fabricated various integrated photonic components including grating …


3d-Printable And Open-Source Modular Smartphone Visible Spectrophotometer, Brandon Winters, Nick Banfield, Cassandra Dixon, Anna Swensen, Dakota Holman, Braxton Fillbrown Oct 2021

3d-Printable And Open-Source Modular Smartphone Visible Spectrophotometer, Brandon Winters, Nick Banfield, Cassandra Dixon, Anna Swensen, Dakota Holman, Braxton Fillbrown

Chemistry Faculty Publications

The past four decades have brought significant and increasingly rapid changes to the world of instrument design, fabrication, and availability due to the emergence of 3D printing, open-source code and equipment, and low-cost electronics. These, along with other technological advances represent a nexus in time ripe for the wide-spread production and availability of low-cost sophisticated scientific equipment. To that end, the design of a 3D printable and open-source, modular spectrometer is described. This specific instrument is distinctly different from others that have been reported in recent years in that it was designed outside of the “black box” paradigm of …


Detecting A Heterogenous Sample Of Pigmented Melanoma Cell Lines Using Photoacoustic Flow Cytometry, Margaret Cappellano May 2021

Detecting A Heterogenous Sample Of Pigmented Melanoma Cell Lines Using Photoacoustic Flow Cytometry, Margaret Cappellano

Electronic Theses and Dissertations

Metastatic melanoma is the deadliest form of skin cancer, which is in part, attributed to its rapid aggression and lack of response to typical treatment methods. There are far too often cases where a lymph node biopsy does not detect the severity of the cancer, which in turn causes a lack of diagnosis until a mass can be visually detected on a scan, such as a PET, CT, or MRI. Once visible on a scan, the cancer is too progressive for successful treatment. To avoid this, we investigated how a blood sample can be used to negate a missed diagnosis, …


Optical Study Of 2-D Detonation Wave Stability, Eulaine T. Grodner Mar 2021

Optical Study Of 2-D Detonation Wave Stability, Eulaine T. Grodner

Theses and Dissertations

Fundamental optical detonation study of detonations constricted to a 2-d plane propagation, and detonations propagating around a curve. All images were processed using modern image processing techniques. The optical techniques used were shadowgraph, Schlieren, and chemiluminescence. In the 2-Dstraight channels, it was determined wave stability was a factor of cell size. It was also determined the detonation wave thickness (area between the combustion and shockwave) was a factor of how much heat available for the detonation. For the detonations propagating around a curve, it was determined the three main classifications of wave stability were stable, unstable, and detonation wave restart. …


Strain-, Curvature- And Twist-Independent Temperature Sensor Based On A Small Air Core Hollow Core Fiber Structure, Dejun Liu, Wei Li, Qiang Wu, Fengzi Ling, Ke Tian, Changyu Shen, Fangfang Wei, Gerald Farrell, Yuliya Semenova, Pengfei Wang Jan 2021

Strain-, Curvature- And Twist-Independent Temperature Sensor Based On A Small Air Core Hollow Core Fiber Structure, Dejun Liu, Wei Li, Qiang Wu, Fengzi Ling, Ke Tian, Changyu Shen, Fangfang Wei, Gerald Farrell, Yuliya Semenova, Pengfei Wang

Articles

Cross-sensitivity (crosstalk) to multiple parameters is a serious but common issue for most sensors and can significantly decrease the usefulness and detection accuracy of sensors. In this work, a high sensitivity temperature sensor based on a small air core (10 µm) hollow core fiber (SACHCF) structure is proposed. Co-excitation of both anti-resonant reflecting optical waveguide (ARROW) and Mach-Zehnder interferometer (MZI) guiding mechanisms in transmission are demonstrated. It is found that the strain sensitivity of the proposed SACHCF structure is decreased over one order of magnitude when a double phase condition (destructive condition of MZI and resonant condition of ARROW) is …


Aqueous Fabrication Of Pristine And Oxide Coated Znse Nanoparticles, Nicholas L. Van Zandt Jan 2021

Aqueous Fabrication Of Pristine And Oxide Coated Znse Nanoparticles, Nicholas L. Van Zandt

Browse all Theses and Dissertations

Semiconducting nanoparticles have received significant attention due to their unique optoelectronic properties. Quantum dots (QDs), a class of spherical nanoparticles, possess a size-dependent bandgap and photoluminescence at visible wavelengths. QDs have many applications including biological labelling, solar cells, chemical impurity detection, and optical glasses. Doping QDs into optical glasses is highly desirable. High-quality QDs can be synthesized via liquid solution methods. However, solution-synthesized QDs often degrade over time and they cannot survive incorporation into a glass melt without protection. In this work, the aqueous synthesis of ZnSe QDs and coating with nanometer silica and alumina protective shells are investigated. The …


Linear And Nonlinear Optical Effects In High Carrier Concentration Oxides And Nitrides At Epsilon-Near-Zero, Ray Secondo Jan 2021

Linear And Nonlinear Optical Effects In High Carrier Concentration Oxides And Nitrides At Epsilon-Near-Zero, Ray Secondo

Theses and Dissertations

Nonlinear optics has been an important method for achieving ultrafast light manipulation. Recently, ENZ material have gained interest due to inherent advantages such as slow light, improved confinement, and ideal relaxation times, the nonlinear response of these materials, such as the intensity-dependent-refractive-index, are ultra-large yet remain ultra-fast. This experimental discovery of epsilon-near-zero enhancement has thus opened new avenues in nonlinear optics research in recent years, and while experiments have continued to progress a theoretical understanding of the processes and origins of nonlinear optical enhancement at epsilon-near-zero has lagged.

To fill this gap, the work herein focuses on uncovering the mechanisms …


Novel Methods In Computational Imaging With Applications In Remote Sensing, Adam Webb Jan 2021

Novel Methods In Computational Imaging With Applications In Remote Sensing, Adam Webb

Dissertations, Master's Theses and Master's Reports

This dissertation is devoted to novel computational imaging methods with applications in remote sensing. Computational imaging methods are applied to three distinct applications including imaging and detection of buried explosive hazards utilizing array radar, high resolution imaging of satellites in geosynchronous orbit utilizing optical hypertelescope arrays, and characterization of atmospheric turbulence through multi-frame blind deconvolution utilizing conventional optical digital sensors.

The first application considered utilizes a radar array employed as a forward looking ground penetrating radar system with applications in explosive hazard detection. A penalized least squares technique with sparsity-inducing regularization is applied to produce imagery, which is consistent with …


Saturation Behaviors In Deep Turbulence, Jeffrey R. R. Beck Jan 2021

Saturation Behaviors In Deep Turbulence, Jeffrey R. R. Beck

Dissertations, Master's Theses and Master's Reports

Distributed-volume atmospheric turbulence near the ground significantly limits the performance of incoherent imaging and coherent beam projection systems operating over long horizontal paths. Defense, military and civilian surveillance, border security, and target identification systems are interested in terrestrial imaging and beam projection over very long horizontal paths, but atmospheric turbulence can blur the imagery and aberrate the laser beam such that they are beyond usefulness. While many post-processing and adaptive optics techniques have been developed to mitigate the effects of turbulence, many of these techniques do not work as expected in stronger volumetric turbulence, or in many cases don't work …


Noninvasive Blood Flow And Oxygenation Measurements In Diseased Tissue, Benjamin S. Rinehart Jan 2021

Noninvasive Blood Flow And Oxygenation Measurements In Diseased Tissue, Benjamin S. Rinehart

Browse all Theses and Dissertations

The research presented in this dissertation focused on the application of optical imaging techniques to establish blood flow and oxygen saturation as effective biomarkers for two disease cases, Autism Spectrum Disorder (ASD) and Huntington’s Disease (HD). The BTBR mouse model of ASD was utilized to validate measurements of cerebral blood flow and oxygenation as biomarkers for autism. The R6/2 mouse model of juvenile HD was utilized to validate measurements of skeletal muscle blood flow following tetanic muscle contractions induced by electrical nerve stimulation. Next, a noncontact, camera-based system to measure blood flow and oxygen saturation maps was implemented to improve …


The Aging And Impacts Of Atmospheric Soot: Closing The Gap Between Experiments And Models, Ogochukwu Yvonne Enekwizu Dec 2020

The Aging And Impacts Of Atmospheric Soot: Closing The Gap Between Experiments And Models, Ogochukwu Yvonne Enekwizu

Dissertations

The main goal of this dissertation is to generate data and parameterizations to accurately represent soot aerosols in atmospheric models. Soot from incomplete combustion of fossil fuels and biomass burning is a major air pollutant and a significant contributor to climate warming. The environmental impacts of soot are strongly dependent on the particle morphology and mixing state, which evolve continuously during atmospheric transport via a process known as aging. To make predictions of soot impacts on the environment, most atmospheric models adopt simplifications of particle structure and mixing state, which lead to substantial uncertainties. Using an experimentally constrained modeling approach, …


Prototype Instrument Development For Measuring Directionality Of Aerosol Light Scattering, Esther K. Monroe Aug 2020

Prototype Instrument Development For Measuring Directionality Of Aerosol Light Scattering, Esther K. Monroe

McKelvey School of Engineering Theses & Dissertations

Investigation of aerosol interactions with electromagnetic waves provides insights into the scattering particles. Aerosol phase function, an angular distribution of scattered light, is a value required to calculate parameters used in direct radiative forcing (DRF) models in the atmosphere. Currently no direct measurement of phase function is available hence it is estimated from ground observations such as backscatter fraction b and subsequently relating the parameters via Henyey-Greenstein (HG) approximation. This method has shown to introduce errors in radiation transfer models. HG phase function, in particular, does not account for particle microphysical properties such as shape and refractive index. Given the …


A Convolutional Neural Network For Fast Fluence Estimation In Complex Tissues, Nicholas Blasey, Geoffrey P. Luke Jun 2020

A Convolutional Neural Network For Fast Fluence Estimation In Complex Tissues, Nicholas Blasey, Geoffrey P. Luke

ENGS 88 Honors Thesis (AB Students)

Photoacoustic (PA) imaging is a non-invasive diagnostic imaging technique that gives images of photoabsorbers based on their absorption of optical energy. These optical absorption properties can then be linked to important tissue properties. For the method to be quantitative, however, it is necessary to have an accurate estimation of the light fluence in the tissue. The current gold standard in addressing the fluence estimation problem, a Monte Carlo Simulation, is costly in time and computation. In this work, we developed a deep neural network to quickly and accurately estimate light fluence in arbitrary tissue types and geometries. The network was …


Miniaturized Ultraviolet Imager Phase Iii, Bradley D. Albright, Nicolas A. Armenta, Colin W. Harrop Jun 2020

Miniaturized Ultraviolet Imager Phase Iii, Bradley D. Albright, Nicolas A. Armenta, Colin W. Harrop

Mechanical Engineering

This document details the work to date, June 9, 2020, done by the Cal Poly Mechanical Engineering senior project team, Miniaturized Ultraviolet Imager: Phase III (MUVI III), sponsored by the University of California, Berkeley – Space Sciences Laboratory (UCB SSL). MUVI III is the third senior project team of an ongoing design, MUVI: the prototype of a 2U sized CubeSat intended to capture aurora images in the ionosphere. The first team, MUVI I, finished development of the UV imager. The second team, MUVI II, designed the mirror mounting and deployable door mechanisms. The goal of MUVI phase III is to …


Integrated Photonic Device, Brittney Kuhn May 2020

Integrated Photonic Device, Brittney Kuhn

Student Scholar Symposium Abstracts and Posters

In computer mediated communication networks, information is typically encoded optically to transmit signals over long distances. At a network node, the optical signal is transformed into the electrical domain, processed electronically, and transformed back to an optical state to reach its destination. Transitioning between optical and electrical encoding of the signal is a potential security weak point, especially for quantum communication links. If information can remain in one state as it travels through the network, then security breaches can be detected and dealt with more easily. Furthermore, keeping the information in one state can reduce power consumption in the network. …


Optics Of Two-Dimensional Materials Used As Substrates For Nanoparticle-Based Devices, Reagan Newman May 2020

Optics Of Two-Dimensional Materials Used As Substrates For Nanoparticle-Based Devices, Reagan Newman

Chancellor’s Honors Program Projects

No abstract provided.


Construction Of A Hyperspectral Imager Using 3d-Printed And Off-The-Shelf Components, Joshua Moorhouse May 2020

Construction Of A Hyperspectral Imager Using 3d-Printed And Off-The-Shelf Components, Joshua Moorhouse

Mechanical Engineering Undergraduate Honors Theses

The Arkansas Center for Space and Planetary Sciences is working in collaboration with the Mechanical Engineering department to create a relatively cheap and modifiable hyperspectral imager. It is constructed using 3D-printed and off-the-shelf components from Edmund Optics and Amazon. The iteration created in this paper delivers spectrograms in the visible spectrum. The long-term goals of the camera are to create hyperspectral images from these spectrograms and to advance the imager into the infrared and near-infrared spectra. This imager is being developed to be used in the Arkansas Center for Space and Planetary Sciences environmental test chambers to further the scientific …


The Design Of A Continuous Wave Molecular Nitrogen Stimulated Raman Laser In The Visible Spectrum, Timothy J. Bate Mar 2020

The Design Of A Continuous Wave Molecular Nitrogen Stimulated Raman Laser In The Visible Spectrum, Timothy J. Bate

Theses and Dissertations

Hollow-core photonic crystal fibers (HCPCFs) shows promise as a hybrid laser with higher nonlinear process limits and small beam size over long gain lengths. This work focuses on the design of a CW molecular nitrogen (N2) stimulated Raman laser. N2 offers Raman gains scaling up to 900 amg, scaling higher than H2. The cavity experiment showed the need to include Rayleigh scattering in the high pressure required for N2 Raman lasing. Even at relatively low pressure ssuch as 1,500 psi, high conversion percentages should be found if the fiber length is chosen based on …