Zernike Piston Statistics In Turbulent Multi-Aperture Optical Systems,
2020
Air Force Institute of Technology
Zernike Piston Statistics In Turbulent Multi-Aperture Optical Systems, Joshua J. Garretson
Theses and Dissertations
There is currently a lack of research into how the atmosphere effects Zernike piston. This Zernike piston is a coefficient related to the average phase delay of a wave. Usually Zernike piston can be ignored over a single aperture because it is merely a delay added to the entire wavefront. For multi-aperture interferometers though piston cannot be ignored. The statistics of Zernike piston could supplement and improve atmospheric monitoring, adaptive optics, stellar interferometers, and fringe tracking. This research will focus on developing a statistical model for Zernike piston introduced by atmospheric turbulence.
Mult-Spectral Imaging Of Vegetation With A Diffractive Plenoptic Camera,
2020
Air Force Institute of Technology
Mult-Spectral Imaging Of Vegetation With A Diffractive Plenoptic Camera, Tristan R. Naranjo
Theses and Dissertations
Snapshot multi-spectral sensors allow for object detection based on its spectrum for remote sensing applications in air or space. By making these types of sensors more compact and lightweight, it allows drones to dwell longer on targets or the reduction of transport costs for satellites. To address this need, I designed and built a diffractive plenoptic camera (DPC) which utilized a Fresnel zone plate and a light field camera in order to detect vegetation via a normalized difference vegetation index (NDVI). This thesis derives design equations by relating DPC system parameters to its expected performance and evaluates its multi-spectral performance. …
Pulsed Laser Generation In S+/S Band Using Thulium Fluoride Fiber With Saturable Absorber,
2020
Universiti Malaya
Pulsed Laser Generation In S+/S Band Using Thulium Fluoride Fiber With Saturable Absorber, Reduan Siti Aisyah
Student Works (2020-2029)
Demands on photonic applications has become highly saturated in C-band and L-band region, forcing the needs to work in S band region for the development of alternative data network and photonics technology tools to fulfill the future needs. There are only a few reports on exploiting S band fiber laser operation which mainly used depressed-cladding erbium-doped fiber (DC-EDF) as gain medium. The region covers only ~1480 nm to 1510 nm as mentioned by previous works. Other than that, there is limitation in the selection of rare-element gain medium to generate the emission in S band region. The use of thulium-fluoride …
Validation Of Hts Optical Turbulence Profiling Via Sonic Anemometry,
2020
Air Force Institute of Technology
Validation Of Hts Optical Turbulence Profiling Via Sonic Anemometry, Alexander S. Boeckenstedt
Theses and Dissertations
Previous turbulence measurements along a near-ground, 500 m, horizontal path using two helium-neon laser beacons and Hartmann Turbulence Sensor (HTS) yielded profiles of C2n by measuring local aberrated wavefront tilts. The HTS C2n estimates were consistent with integrated turbulence values collected along the same path by a BLS900 scintillometer. Further validation of the HTS profiling method is necessary to produce accurate optical turbulence profiles for wavefront correction and to eventually gain an improved understanding of turbulence in the lower atmosphere and its variation as a function of altitude. In order to add confidence to the HTS …
Global Gradient-Based Phase Unwrapping Algorithm For Increased Performance In Wavefront Sensing,
2020
Air Force Institute of Technology
Global Gradient-Based Phase Unwrapping Algorithm For Increased Performance In Wavefront Sensing, Bryan R. Bartelt
Theses and Dissertations
As the reliance on satellite data for military and commercial use increases, more effort must be exerted to protect our space-based assets. In order to help increase our space domain awareness (SDA), new approaches to ground-based space surveillance via wavefront sensing must be adopted. Improving phase-unwrapping algorithms in order to assist in phase retrieval methods is one way of increasing the performance in current adaptive optics (AO) systems. This thesis proposes a new phase-unwrapping algorithm that uses a global, gradient-based technique to more rapidly identify and correct for areas of phase wrapping during particular phase retrieval methods. This is beneficial …
Synthesizing General Electromagnetic Partially Coherent Sources From Random, Correlated Complex Screens,
2020
Air Force Institute of Technology
Synthesizing General Electromagnetic Partially Coherent Sources From Random, Correlated Complex Screens, Milo W. Hyde Iv
Faculty Publications
We present a method to generate any genuine electromagnetic partially coherent source (PCS) from correlated, stochastic complex screens. The method described here can be directly implemented on existing spatial-light-modulator-based vector beam generators and can be used in any application which utilizes electromagnetic PCSs. Our method is based on the genuine cross-spectral density matrix criterion. Applying that criterion, we show that stochastic vector field realizations (corresponding to a desired electromagnetic PCS) can be generated by passing correlated Gaussian random numbers through “filters” with space-variant transfer functions. We include step-by-step instructions on how to generate the electromagnetic PCS field realizations. As an …
Non-Linear Statistical Photocalibration Of Photodetectors Without Calibrated Light Sources,
2020
Air Force Institute of Technology
Non-Linear Statistical Photocalibration Of Photodetectors Without Calibrated Light Sources, Stephen C. Cain
Faculty Publications
Calibration of CCD arrays is commonly conducted using dark frames. Non-absolute calibration techniques only measure the relative response of the detectors. For absolute calibration to be achieved, a second calibration is sometimes utilized by looking at sources with known radiances. A process like this can be used to calibrate photodetectors if a calibration source is available and sensor time can be spared to perform the operation. A previous attempt at creating a procedure for calibrating a photodetector using the underlying Poisson nature of the photodetection statistics relied on a linear model. This effort produced the statistically applied non-uniformity calibration algorithm, …
A Computationally-Efficient Bound For The Variance Of Measuring The Orientation Of Single Molecules,
2020
Washington University in St. Louis
A Computationally-Efficient Bound For The Variance Of Measuring The Orientation Of Single Molecules, Tingting Wu, Tianben Ding, Hesam Mazidi, Oumeng Zhang, Matthew D. Lew
Electrical & Systems Engineering Publications and Presentations
Modulating the polarization of excitation light, resolving the polarization of emitted fluorescence, and point spread function (PSF) engineering have been widely leveraged for measuring the orientation of single molecules. Typically, the performance of these techniques is optimized and quantified using the Cramér-Rao bound (CRB), which describes the best possible measurement variance of an unbiased estimator. However, CRB is a local measure and requires exhaustive sampling across the measurement space to fully characterize measurement precision. We develop a global variance upper bound (VUB) for fast quantification and comparison of orientation measurement techniques. Our VUB tightly bounds the diagonal elements of the …
Measuring Localization Confidence For Quantifying Accuracy And Heterogeneity In Single-Molecule Super-Resolution Microscopy,
2020
Washington University in St. Louis
Measuring Localization Confidence For Quantifying Accuracy And Heterogeneity In Single-Molecule Super-Resolution Microscopy, Hesam Mazidi, Tianben Ding, Arye Nehorai, Matthew D. Lew
Electrical & Systems Engineering Publications and Presentations
We present a computational method, termed Wasserstein-induced flux (WIF), to robustly quantify the accuracy of individual localizations within a single-molecule localization microscopy (SMLM) dataset without ground- truth knowledge of the sample. WIF relies on the observation that accurate localizations are stable with respect to an arbitrary computational perturbation. Inspired by optimal transport theory, we measure the stability of individual localizations and develop an efficient optimization algorithm to compute WIF. We demonstrate the advantage of WIF in accurately quantifying imaging artifacts in high-density reconstruction of a tubulin network. WIF represents an advance in quantifying systematic errors with unknown and complex distributions, …
Edge-Coupling Of O-Band Inp Etched-Facet Lasers To Polymer Waveguides On Soi By Micro-Transfer-Printing,
2020
Tyndall National Institute at National University of Ireland, Cork
Edge-Coupling Of O-Band Inp Etched-Facet Lasers To Polymer Waveguides On Soi By Micro-Transfer-Printing, Ruggero Loi, Steven Kelleher, Raja Fazan Gul, Antonio Jose Trindade, David Gomez, Liam O'Faolain, Brian Corbett, Simone Iadanza, Brendan Roycroft, James O'Callaghan, Lei Liu, Kevin Thomas, Agnieszka Gocalinska, Emanuele Pelucchi, Alexander Farrell
Cappa Publications
O-band InP etched facets lasers were heterogeneously integrated by micro-transfer-printing into a 1.54~\mu \text{m} deep recess created in the 3~\mu \text{m} thick oxide layer of a 220 nm SOI wafer. A 7\times 1.5\,\,\mu \text{m}^{2} cross-section, 2 mm long multimode polymer waveguide was aligned to the ridge post-integration by e-beam lithography with < 0.7~\mu \text{m} lateral misalignment and incorporated a tapered silicon waveguide. A 170 nm thick metal layer positioned at the bottom of the recess adjusts the vertical alignment of the laser and serves as a thermal via to sink the heat to the Si substrate. This strategy shows a roadmap for active polymer waveguide-based photonic integrated circuits.
Validation Of Trap Density Theory In Single Layer Organic Light Emitting Diodes With Tris(8 Hydroxyquinolinato)Aluminium As The Emissive Material,
2020
Universiti Malaya
Validation Of Trap Density Theory In Single Layer Organic Light Emitting Diodes With Tris(8 Hydroxyquinolinato)Aluminium As The Emissive Material, Zaini Mohd Suffian
Student Works (2020-2029)
Organic light-emitting diodes (OLEDs) rapidly evolving as the future of solid-state lighting and display application due to its numerous advantages and features. However, the efficiency, lifetime, and fabrication method still need to be improved. Even in solving efficiency issues in the device, there are many challenges to be addressed and overcome. In theory, charge transport phenomena contribute greatly towards increasing or improving the device efficiency. The magnitude of carrier mobility determines the performance of the device, as it influenced device efficiency. For organic semiconductor such as OLED, space-charge limited current (SCLC) theory was used to determine the mobility of the …
Overview Of Trends In Indian Optics Research (2008 – 2018),
2020
Kuvempu University
Overview Of Trends In Indian Optics Research (2008 – 2018), Mallikarjun Kappi, Biradar B S
Library Philosophy and Practice (e-journal)
The present study deals with the assessment of Indian optics research output as reflected in Web of Science (WOS) database for the period 2008 to 2018 for identifying the research output in the field of optics literature. It also provides a comparative evaluation and performance of different types of scientometric indicators, such as number of publications, number of citations and collaboration from India. The Indian optics research has increased exponentially over the last decade.
In-Situ Gold-Ceria Nanoparticles: Superior Optical Fluorescence Quenching Sensor For Dissolved Oxygen,
2020
Old Dominion University
In-Situ Gold-Ceria Nanoparticles: Superior Optical Fluorescence Quenching Sensor For Dissolved Oxygen, Nader Shehata, Ishac Kandas, Effat Samir
Electrical & Computer Engineering Faculty Publications
Cerium oxide (ceria) nanoparticles (NPs) have been proved to be an efficient optical fluorescent material through generating visible emission (~530 nm) under violet excitation. This feature allowed ceria NPs to be used as an optical sensor via the fluorescence quenching Technique. In this paper, the impact of in-situ embedded gold nanoparticles (Au NPs) inside ceria nanoparticles was studied. Then, gold–ceria NPs were used for sensing dissolved oxygen (DO) in aqueous media. It was observed that both fluorescence intensity and lifetime were changed due to increased concentration of DO. Added gold was found to enhance the sensitivity of ceria to DO …
Nanoscale Colocalization Of Fluorogenic Probes Reveals The Role Of Oxygen Vacancies In The Photocatalytic Activity Of Tungsten Oxide Nanowires,
2020
Washington University in St. Louis
Nanoscale Colocalization Of Fluorogenic Probes Reveals The Role Of Oxygen Vacancies In The Photocatalytic Activity Of Tungsten Oxide Nanowires, Meikun Shen, Tianben Ding, Steven T. Hartman, Fudong Wang, Christina Krucylak, Zheyu Wang, Che Tan, Bo Yin, Rohan Mishra, Matthew D. Lew, Bryce Sadtler
Electrical & Systems Engineering Publications and Presentations
Defect engineering is a strategy that has been widely used to design active semiconductor photocatalysts. However, understanding the role of defects, such as oxygen vacancies, in controlling photocatalytic activity remains a challenge. Here, we report the use of chemically triggered fluorogenic probes to study the spatial distribution of active regions in individual tungsten oxide nanowires using super-resolution fluorescence microscopy. The nanowires show significant heterogeneity along their lengths for the photocatalytic generation of hydroxyl radicals. Through quantitative, coordinate-based colocalization of multiple probe molecules activated by the same nanowires, we demonstrate that the nanoscale regions most active for the photocatalytic generation of …
Tilt Measurements Using A Monolithic Cyclic Interferometer,
2020
Rose-Hulman Institute of Technology
Tilt Measurements Using A Monolithic Cyclic Interferometer, Joseph Porter
Graduate Theses - Physics and Optical Engineering
Measurement applications globally are demanding higher resolution measurements within a smaller footprint. The cyclic interferometer is a proven means of high-resolution tilt measurements while maintaining fringe stability. However, the cyclic interferometer commonly has many optical elements over a large surface area. In this thesis, a monolithic cyclic interferometer has been designed, constructed, and characterized. The monolithic system contains all the functionality of a typical cyclic interferometer, yet the optical elements are contained within a single glass optic. In doing so, the system attains a compact form factor and it is possible to complete measurements within a broader field of application.
Structuring Light For Investigating Optical Vortices,
2020
University of Denver
Structuring Light For Investigating Optical Vortices, Andrew Voitiv, Mark Siemens
DU Undergraduate Research Journal Archive
Vortices are well known in our world: tornadoes, hurricanes, and quickly stirred iced tea all demonstrate the vortex phenomenon. In addition to these classical fluids, vortices exist in laser light. While classical fluid vortex dynamics is one of the oldest studied physics problems, the study of optical vortices is only a few decades old. Paralleling the community’s curiosity of quantized vortices in quantum fluids, such as super fluid helium and Bose-Einstein condensate, there is immense interest in the study of optical vortices. In this article, we cover the basic theory of structuring light to generate optical vortices and then discuss …
Dual-Axis Solar Tracker,
2020
Central Washington University
Dual-Axis Solar Tracker, Bryan Kennedy
All Undergraduate Projects
Renewable energies, and fuels that are not fossil fuel-based, are one of the prolific topics of debate in modern society. With climate change now becoming a primary focus for scientists and innovators of today, one of the areas for the largest amount of potential and growth is that of the capturing and utilization of Solar Energy. This method involves using a mechanical system to track the progression of the sun as it traverses the sky throughout the day. A dual-axis solar tracker such as the one designed and built for this project, can follow the sun both azimuthally and in …
Characterizing Complexity In A Semiconductor With Optical Feedback From Two Mirrors,
2020
Eastern Washington University
Characterizing Complexity In A Semiconductor With Optical Feedback From Two Mirrors, Layla M. Abrams
2020 Symposium Posters
Lasers are stable devices with a broad spectrum of applications. They can be perturbed to induce complex dynamics in their output intensity. One interesting regime in semiconductor lasers is that the output intensity of the laser emits a sequence of non-regular optical spikes. This behavior resembles that of neurons. We use a semiconductor laser with optical feedback from two mirrors to characterize the behavior of the laser's power output. The data is then analyzed by transforming the intensity time series into a sequence of patterns or words. By doing this we want to explore how the laser changes its preferred …
Ensemble Lung Segmentation System Using Deep Neural Networks,
2020
University of Dayton
Ensemble Lung Segmentation System Using Deep Neural Networks, Redha A. Ali, Russell C. Hardie, Hussin K. Ragb
Electrical and Computer Engineering Faculty Publications
Lung segmentation is a significant step in developing computer-aided diagnosis (CAD) using Chest Radiographs (CRs). CRs are used for diagnosis of the 2019 novel coronavirus disease (COVID-19), lung cancer, tuberculosis, and pneumonia. Hence, developing a Computer-Aided Detection (CAD) system would provide a second opinion to help radiologists in the reading process, increase objectivity, and reduce the workload. In this paper, we present the implementation of our ensemble deep learning model for lung segmentation. This model is based on the original DeepLabV3+, which is the extended model of DeepLabV3. Our model utilizes various architectures as a backbone of DeepLabV3+, such as …
Nis2 As A Broadband Saturable Absorber For Ultrafast Pulse Lasers,
2020
Shenzhen University
Nis2 As A Broadband Saturable Absorber For Ultrafast Pulse Lasers, Pengfei Wang, Han Zhang, Yu Yin, Qiuyun Ouyang, Yujin Chen, Elfed Lewis, Gerald Farrell, Masaki Tokurakawa, Sulaiman Wadi Harun, Cong Wang, Shi Li
Articles
Nickel disulfide (NiS2) has recently been found to possess strong nonlinear saturable absorption properties. This feature is highly attractive for nonlinear photonics applications. Ultrafast pulse generation is successfully demonstrated in this article for both Ytterbium- and Erbium-doped fibre lasers using micro-fibre deposited nickel disulfide (NiS2) as a saturable absorber (SA). The fabricated SA device has a modulation depth of 23% at 1.06 μm and 30.8% at 1.55 μm. Stable dissipative soliton operation was achieved at 1064.5 nm with a pulse duration of 11.7 ps and another stable conventional soliton pulse train was also obtained at 1560.2 nm with a pulse …
