Intense Mid-Infrared Emission At 3.9 Μm In Ho3+-Doped Zbya Glasses For Potential Use As A Fiber Laser,
2020
Harbin Engineering University
Intense Mid-Infrared Emission At 3.9 Μm In Ho3+-Doped Zbya Glasses For Potential Use As A Fiber Laser, Haiyan Zhao, Ruicong Wang, Xin Wang, Shijie Jia, Yaxian Fan, Elfed Lewis, Gerald Farrell, Shunbin Wang, Pengfei Wang
Articles
Intense mid-infrared emission at 3.9 µm in Ho3+-doped ZBYA glasses with direct upper laser level (Ho3+ : 5 I5) pumping at a wavelength of 888 nm is reported for the first time, to the best of our knowledge. Spectroscopic parameters were determined using the Judd–Ofelt theory and the measured absorption spectrum. The maximum emission cross section of the Ho3+-doped ZBYA glass is estimated to be 2.7 × 10−21 cm2 at 3906 nm. Additionally, fluorescence spectra and lifetimes of ZBYA glasses with different Ho3+ ion doping concentrations were measured. The results provide theoretical and experimental basis for better selection of rare-earth-doped …
Holographic Security,
2020
Technological University Dublin
Holographic Security, Vincent Toal
Books/Book Chapters
This chapter is concerned with the security applications of holographic techniques. Holograms are used in product authentication, product branding and brand protection, and personal and other documents. Serialization to ensure the uniqueness of each hologram for added security is briefly discussed. The theory of optical character recognition and joint transform correlation methods is outlined. Holographic recording using encrypted reference waves enables secure storage of information. Several methods are considered for encrypting optical data as well as holographic recording of encrypted images and their reconstruction and decryption. Millimeter and microwave holographic imaging techniques for the detection of hidden contraband, narcotics, firearms, …
Thermodynamic Theory Of Heavily Multimoded Nonlinear Optical Systems,
2020
University of Central Florida
Thermodynamic Theory Of Heavily Multimoded Nonlinear Optical Systems, Fan Wu
Electronic Theses and Dissertations, 2020-2023
The quest for ever higher information capacities has brought about a renaissance in multimode optical waveguide systems. This resurgence of interest has recently initiated a flurry of activities in nonlinear multimode fiber optics. The sheer complexity emerging from the presence of a multitude of nonlinearly interacting modes has led not only to new opportunities in observing a host of novel optical effects that are otherwise impossible in single-mode settings, but also to new theoretical challenges in understanding their collective dynamics. In this dissertation, we present a consistent thermodynamical framework capable of describing in a universal fashion the exceedingly intricate behavior …
High Performance Micro-Scale Light Emitting Diode Display,
2020
University of Central Florida
High Performance Micro-Scale Light Emitting Diode Display, Fangwang Gou
Electronic Theses and Dissertations, 2020-2023
Micro-scale light emitting diode (micro-LED) is a potentially disruptive display technology because of its outstanding features such as high dynamic range, good sunlight readability, long lifetime, low power consumption, and wide color gamut. To achieve full-color displays, three approaches are commonly used: 1) to assemble individual RGB micro-LED pixels from semiconductor wafers to the same driving backplane through pick-and-place approach, which is referred to as mass transfer process; 2) to utilize monochromatic blue micro-LED with a color conversion film to obtain a white source first, and then employ color filters to form RGB pixels, and 3) to use blue or …
Novel Fibers And Components For Space Division Multiplexing Technologies,
2020
University of Central Florida
Novel Fibers And Components For Space Division Multiplexing Technologies, Juan Carlos Alvarado Zacarias
Electronic Theses and Dissertations, 2020-2023
Passive devices and amplifiers for space division multiplexing are key components for future deployment of this technology and for the development of new applications exploring the spatial diversity of light. Some important devices include photonic lantern (PL) mode multiplexers supporting several modes, fan-in/fan-out (FIFO) devices for multicore fibers (MCFs), and multimode amplifiers capable of amplifying several modes with low differential modal gain penalty. All these components are required to overcome the capacity limit of single mode fiber (SMF) communication systems, driven by the growing data capacity demand. In this dissertation I propose and develop different passive components and amplifiers for …
Optimisation Of The Performance Of Holographic Beam-Shaping Diffractive Diffusers Through Refinement Of The Recording Process,
2020
Technological University Dublin
Optimisation Of The Performance Of Holographic Beam-Shaping Diffractive Diffusers Through Refinement Of The Recording Process, Cara Jones, Suzanne Martin, Sanjay Keshri, Dervil Cody, Kevin Murphy
Conference Papers
Optical diffusers have uses in laser applications and machine vision. Typical fabrication at a commercial level requires master production and the stamping/copying of individual elements at scale. This expensive, indirect process inhibits custom diffusers at reasonable cost. Previously the authors published a novel, direct, single beam method of recording customizable and controllable volume holographic diffusers by manipulating laser speckle and recording the pattern in photopolymer. This method allows for beam-shaping to produce diffusion patterns of various sizes and shapes. In this work, the direct method of recording controllable holographic diffusers is refined to improve diffuser performance (i.e., a decrease in …
Corrections To ‘‘Glaciernet: A Deep-Learning Approach For Debris-Covered Glacier Mapping’’,
2020
University of Dayton
Corrections To ‘‘Glaciernet: A Deep-Learning Approach For Debris-Covered Glacier Mapping’’, Zhiyuan Xie, Umesh K. Haritashya, Vijayan K. Asari, Brennan W. Young, Michael P. Bishop, Jeffrey S. Kargel
Electrical and Computer Engineering Faculty Publications
In the above article [1], Figure 2 was incorrect. Unfortunately, we mixed the color label of "CONV $\to $ BN $\to $ ReLu" and "Unpooling" in the CNN structure section of Figure 2. The color label of "CONV $\to $ BN $\to $ ReLu" should be orange while the color label of "Unpooling" should be green. Also, the word "Decoder" is misspelled. That same figure with the same error is also used for the graphic abstract. The corrected figure is given here. None of the sections in the figure is modified. The only change is in the color label of …
Wave-Optics Simulation Of Correlated Speckle Fields,
2020
University of Central Florida
Wave-Optics Simulation Of Correlated Speckle Fields, Derek Burrell
Electronic Theses and Dissertations, 2020-2023
Laser speckle poses an ongoing challenge to optical systems that utilize coherent light for active illumination, including applications in holography, free-space communications, remote sensing and target tracking. Speckle averaging offers one potential path forward by reducing the contrast, thereby boosting signal-to-noise ratios. This approach becomes limited, however, by the degree of correlation between successive frames. Wave-optics simulations help to characterize performance gains through speckle averaging, and so it is important that existing models properly account for decorrelation rates of dynamic speckle. With that goal in mind, this research seeks to build a suite of computational wave-optics experiments that verify speckle …
Transient Mid-Ir Nonlinear Refraction In Air And Nonlinear Optical Properties Of Organometallic Complexes,
2020
University of Central Florida
Transient Mid-Ir Nonlinear Refraction In Air And Nonlinear Optical Properties Of Organometallic Complexes, Salimeh Tofighi
Electronic Theses and Dissertations, 2020-2023
This dissertation explores two main topics: Transient nonlinear refraction of air in Mid-IR spectral range and nonlinear optical properties of organometallic complexes. For seeing a vibrational and rotational Raman response the molecule should be Raman active. The first requirement for being a Raman active molecule is that the polarizability of molecule must be anisotropic. Linear symmetric molecules do have rotational Raman spectra. Not all the vibrational mode can be excited by a femtosecond pulse. The pulsewidth of our excitation beam should be less than the half of the vibration period. In this dissertation my excitation pulsewidth is not short enough …
Development Of High-Power Single-Mode Yb-Doped Fiber Amplifiers And Beam Analysis,
2020
University of Central Florida
Development Of High-Power Single-Mode Yb-Doped Fiber Amplifiers And Beam Analysis, Steffen Wittek
Electronic Theses and Dissertations, 2020-2023
High-power fiber laser systems enjoy a widespread use in manufacturing, medical, and defense applications as well as scientific research, due to their remarkable power scalability, high electrical to optical efficiency, compactness and ruggedness. However, single-mode fiber power scaling has stagnated in the past years, primarily due to the onset of nonlinear effects such as stimulated Brillouin/Raman scattering and transverse modal instabilities. This thesis addresses the analysis and mitigation of transverse modal instabilities in high-power fiber amplifiers. I describe the high-power fiber amplifier testbed that I set up to test fibers fabricated in house. I will show our results of a …
Attosecond Transient Absorption Spectroscopy In The Water Window,
2020
University of Central Florida
Attosecond Transient Absorption Spectroscopy In The Water Window, Andrew Chew
Electronic Theses and Dissertations, 2020-2023
The push to study the atomic and molecular dynamics at ever smaller time scales has been the main driving force for developing laser systems with ever shorter pulse durations. Thus far, picosecond lasers and femtosecond lasers have been used with great success in femtochemistry to study molecular dynamics such as molecular rotation and vibration, which all occur in the tens to hundreds of femtosecond. To study electron dynamics however, which are on the order of attoseconds, one needs attosecond laser sources to be able to have the time resolution required to probe ultrafast electron dynamics such as AC Stark shifts, …
Simultaneous Measurement Of Displacement And Temperature Based On Two Cascaded Balloon-Like Bent Fibre Structures,
2020
Harbin Engineering University
Simultaneous Measurement Of Displacement And Temperature Based On Two Cascaded Balloon-Like Bent Fibre Structures, Ke Tian, Ruoning Wang, Meng Zhang, Xiafan Wang, Xin Wang, Guoyong Jin, Elfed Lewis, Gerald Farrell, Pengfei Wang
Articles
A low-cost optical fibre sensor based on two cascaded balloon-like bent fibre (BBF) structures for simultaneous displacement and temperature measurement is reported. The sensor is fabricated by cascading two balloon-like bent single-mode fibres (SMFs) which with different bending radii, generating two separate interference dips within a limited wavelength range. The wavelength of the two interference dips exhibits different responses to external displacement and temperature variations, hence simultaneous measurement of displacement and temperature is realized. Experimental results show that the proposed optical fibre sensor achieves a displacement sensitivity of −318.8 pm/μm and a temperature sensitivity of 47.4 pm/°C. Taking advantage of …
High-Sensitivity Temperature Sensor Based On Anti-Resonance In High-Index Polymer-Coated Optical Fiber Interferometers,
2020
Technological University Dublin
High-Sensitivity Temperature Sensor Based On Anti-Resonance In High-Index Polymer-Coated Optical Fiber Interferometers, Xiaokang Lian, Qiang Wu, Gerald Farrell, Yuliya Semenova
Articles
Compared to the multimode interference (MMI) effect, the anti-resonance (AR) effect does not rely on the multimode property of the optical waveguide. This Letter shows that fiber bending can suppress the MMI and can break the superposition of AR spectra of multiple modes in a high-index polymer-coated optical fiber interferometer based on a single-mode fiber-polymer-coated no-core fiber-single-mode fiber hetero-structure. This results in the dominance of the AR spectrum of an individual mode and consequently in periodic sharp transmission dips. As a result of this phenomenon and large thermo-optical and thermal expansion coefficients of the polymer, a compact, high-sensitivity and linear …
Microspheres With Atomic-Scale Tolerances Generate Hyperdegeneracy,
2020
Technion-Israel Institute of Technology
Microspheres With Atomic-Scale Tolerances Generate Hyperdegeneracy, Jacob Kher-Alden, Shai Maayani, Leopoldo L. Martin, Mark Douvidzon, Lev Deych, Tal Carmon
Publications and Research
Degeneracies play a crucial rule in precise scientific measurements as well as in sensing applications. Spherical resonators have a high degree of degeneracy thanks to their highest symmetry; yet, fabricating perfect spheres is challenging because even a stem to hold the sphere breaks the symmetry. Here we fabricate a levitating spherical resonator that is evanescently coupled to a standard optical fiber. We characterize the resonators to exhibit an optical quality factor exceeding a billion, 10 μm radius, and sphericity to within less than 1µ. Using our high quality and sphericity, we experimentally lift degeneracies of orders higher than 200, which …
High-Fidelity Mini-Led And Micro-Led Displays,
2020
University of Central Florida
High-Fidelity Mini-Led And Micro-Led Displays, Yuge Huang
Electronic Theses and Dissertations, 2020-2023
Mini-LED and micro-LED are emerging disruptive display technologies, because they can work as local dimmable backlight to significantly enhance the dynamic range of conventional LCDs, or as sunlight readable emissive displays. However, there are still unresolved issues impairing their display fidelity: 1) motion blur on high-resolution, large-size and high-luminance devices, 2) limited contrast ratio on mini-LED backlit LCD (mLED-LCD), 3) relatively high power consumption, and 4) compromised ambient contrast ratio. This dissertation tackles with each of these issues for achieving high display fidelity. Motion blur is caused by slow liquid crystal response time and image update delays. Low-duty ratio operation …
Multi-Parameter Optical Metrology: Quantum And Classical,
2020
University of Central Florida
Multi-Parameter Optical Metrology: Quantum And Classical, Walker Larson
Electronic Theses and Dissertations, 2020-2023
The insights offered by quantum mechanics to the field of optical metrology are many-fold, with non-classical states of light themselves used to make sensors that surpass the sensitivity of sensors using classical states of light. Unfortunately, this advantage, referred to often as "super-sensitivity" is notoriously fragile, and even the slightest experimental imperfections may greatly reduce the efficacy of the non-classical sensors, sometimes completely obviating their advantage. In my thesis I have shown that the performance of an otherwise ideal two-photon interferometer, which exploits entanglement between photons to make super-sensitive measurements of phase, is crippled by the slightest introduction of decoherence …
Midwave Vs Longwave Infrared Search And Track And Aerosol Scattering Target Acquisition Performance,
2020
University of Central Florida
Midwave Vs Longwave Infrared Search And Track And Aerosol Scattering Target Acquisition Performance, Steven Butrimas
Electronic Theses and Dissertations, 2020-2023
The decision on whether to use a mid wave infrared (MWIR) or long wave infrared (LWIR) sensor for a given task can be a formidable verdict. The scope entails facts about the observable source, the atmospheric interactions, and the sensor parameters within the hardware device. Even when all the individual metrics are known, the combination ultimately determines whether a MWIR or LWIR sensor is more appropriate. Despite the vast number of variables at play, the reduction of inputs through focused studies can provide essential insight into MWIR and LWIR comparisons. This dissertation focuses on the roles of point source target …
Heterogeneous Integrated Photonics For Nonlinear Frequency Conversion And Polarization Diversity,
2020
University of Central Florida
Heterogeneous Integrated Photonics For Nonlinear Frequency Conversion And Polarization Diversity, Tracy Sjaardema
Electronic Theses and Dissertations, 2020-2023
Silicon has proven to be one of the materials of choice for many integrated photonic applications. However, silicon photonics is limited by certain material shortcomings. Two shortcomings addressed in this work are zero second-order optical nonlinearity, and the lack of methods available to achieve broadband polarization diversity. Heterogeneous integrated solutions for these shortcomings of silicon photonics are presented in this work. First, nonlinear frequency conversion is demonstrated with thin-film lithium niobate on silicon substrates. The method for reaching the highest-achieved second-harmonic generation conversion efficiency, using active monitoring during periodic poling, is discussed. Additionally, a cascaded approach for generating higher-order harmonics …
Few-Mode Fiber Lasers And Amplifiers,
2020
University of Central Florida
Few-Mode Fiber Lasers And Amplifiers, Ning Wang
Electronic Theses and Dissertations, 2020-2023
Lasers and amplifiers of high-order spatial modes are useful for a number of applications, including communication, sensing, microscopy, and laser material processing. This dissertation presents the generation and amplification of high-order spatial modes in few-mode fibers (FMFs). In the area of amplification of high-order spatial modes, low-crosstalk amplification among spatial modes is realized in a retro-reflecting few-mode Er-doped fiber amplifier (EDFA) by exploiting the unitary property of the coupling matrix of a symmetric photonic lantern (PL). A small-signal gain larger than 25 dB and crosstalk below -10 dB was achieved over the C-band for a 3-mode EDFA. Such a few-mode …
Ev Charging Behavior Analysis Using Hybrid Intelligence For 5g Smart Grid,
2020
Rutgers University - Newark
Ev Charging Behavior Analysis Using Hybrid Intelligence For 5g Smart Grid, Yi Shen, Wei Fang, Feng Ye, Michel Kadoch
Electrical and Computer Engineering Faculty Publications
With the development of the Internet of Things (IoT) and the widespread use of electric vehicles (EV), vehicle-to-grid (V2G) has sparked considerable discussion as an energy-management technology. Due to the inherently high maneuverability of EVs, V2G systems must provide on-demand service for EVs. Therefore, in this work, we propose a hybrid computing architecture based on fog and cloud with applications in 5G-based V2G networks. This architecture allows the bi-directional flow of power and information between schedulable EVs and smart grids (SGs) to improve the quality of service and cost-effectiveness of energy service providers. However, it is very important to select …
