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Modulation Identification And Carrier Recovery System For Adaptive Modulation In Satellite Communications, Kenta Umebayashi, Robert H. Morelos-Zaragoza, Ryuji Kohno Jan 2005

Modulation Identification And Carrier Recovery System For Adaptive Modulation In Satellite Communications, Kenta Umebayashi, Robert H. Morelos-Zaragoza, Ryuji Kohno

Faculty Publications

We introduce the modulation identification technique implementing the multimode phase locked loop (PLL) in the satellite communication using adaptive modulation scheme which is a countermeasure against the rain attenuation. In the multimode PLL, phase lock detectors (PLDs) are used for not only phase lock, but also modulation identification. We present the sub-optimized design of the PLDs for modulation identification with respect to the throughput and show the validity of sub-optimization. In addition, by the comparison between the multimode PLL and conventional scheme in ISDB-S, we present the effectivity of the multimode PLL.

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Theoretical And Experimental Investigations Of Macro-Bend Losses For Standard Single Mode Fibers, Qian Wang, Gerald Farrell, Thomas Feir Jan 2005

Theoretical And Experimental Investigations Of Macro-Bend Losses For Standard Single Mode Fibers, Qian Wang, Gerald Farrell, Thomas Feir

Articles

Modeling of macro-bend losses for single mode fibers with multiple cladding or coating layers is presented. Macro-bend losses for standard single mode fibers (SMF28) are investigated theoretically and experimentally, showing that the inner primary coating layer of SMF28 has a significant impact on the bend losses and most of the radiation field is absorbed in the inner primary coating layer of SMF28. The agreement between theoretical calculations and experimental measurements suggests that the so-called elastooptical correction in modeling is not required for SMF28.

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Use Of Advanced Synthesis Tools In Teaching Vlsi Design, Kevin Berwick, Dominic Nardone Jan 2005

Use Of Advanced Synthesis Tools In Teaching Vlsi Design, Kevin Berwick, Dominic Nardone

Articles

No abstract provided.

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Analysis And Implementation Of Ripple Current Cancellation Technique For Electronic Ballasts, Marius G. Marita Jan 2005

Analysis And Implementation Of Ripple Current Cancellation Technique For Electronic Ballasts, Marius G. Marita

ETD Archive

No abstract provided.

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Analysis And Simulation Tools For Solar Array Power Systems, Nattorn Pongratananukul Jan 2005

Analysis And Simulation Tools For Solar Array Power Systems, Nattorn Pongratananukul

Electronic Theses and Dissertations

This dissertation presents simulation tools developed specifically for the design of solar array power systems. Contributions are made in several aspects of the system design phases, including solar source modeling, system simulation, and controller verification. A tool to automate the study of solar array configurations using general purpose circuit simulators has been developed based on the modeling of individual solar cells. Hierarchical structure of solar cell elements, including semiconductor properties, allows simulation of electrical properties as well as the evaluation of the impact of environmental conditions. A second developed tool provides a co-simulation platform with the capability to verify the …

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Solar-Based Single-Stage High-Efficiency Grid-Connected Inverter, Feng Tian Jan 2005

Solar-Based Single-Stage High-Efficiency Grid-Connected Inverter, Feng Tian

Electronic Theses and Dissertations

Renewable energy source plays an important role in the energy cogeneration and distribution. Traditional solar-based inverter system is two stages in cascaded, which has a simpler controller but low efficiency. A new solar-based single-stage grid-connected inverter system can achieve higher efficiency by reducing the power semiconductor switching loss and output stable and synchronized sinusoid current into the utility grid. Controlled by the digital signal processor, the inverter can also draw maximum power from the solar array, thereby maximizing the utilization of the solar array. In Chapter 1, a comparison between the traditional two-stage inverter and the single-stage inverter is made. …

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Analysis And Design Of A Modular Solar-Fed Fault-Tolerant Power System With Maximum Power Point Tracking, Hussam Al-Atrash Jan 2005

Analysis And Design Of A Modular Solar-Fed Fault-Tolerant Power System With Maximum Power Point Tracking, Hussam Al-Atrash

Electronic Theses and Dissertations

Solar power is becoming ever more popular in a variety of applications. It is particularly attractive because of its abundance, renewability, and environment friendliness. Solar powered spacecraft systems have ever-expanding loads with stringent power regulation specifications. Moreover, they require a light and compact design of their power system. These constraints make the optimization of power harvest from solar arrays a critical task. Florida Power Electronics Center (FPEC) at UCF set to develop a modular fault-tolerant power system architecture for space applications. This architecture provides a number of very attractive features including Maximum Power Point Tracking (MPPT) and uniform power stress …

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Design And Implementation Of Wireles Sensor Networks For Parking Management System, Sudhir Chandrasekar Kora Jan 2005

Design And Implementation Of Wireles Sensor Networks For Parking Management System, Sudhir Chandrasekar Kora

Electronic Theses and Dissertations

The technology of wirelessly networked micro sensors promises to revolutionize the way we interact with the physical environment. A new approach to solve parking-related issues of vehicles in parking lots using wireless sensor networks is presented. This approach enables the implementation of the Parking Management System (PMS®) in public parking lots found in Airports, Commercial Buildings, Universities, etc. The design architecture of the sensor nodes is discussed here. An overall view of the sensor network, which covers the whole of the parking lot, is also summarized. Detailed description of the software architecture that supports the hardware is provided. A sample …

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Frequency Domain Independent Component Analysis Applied To Wireless Communications Over Frequency-Selective Channels, Yuan Liu Jan 2005

Frequency Domain Independent Component Analysis Applied To Wireless Communications Over Frequency-Selective Channels, Yuan Liu

Electronic Theses and Dissertations

In wireless communications, frequency-selective fading is a major source of impairment for wireless communications. In this research, a novel Frequency-Domain Independent Component Analysis (ICA-F) approach is proposed to blindly separate and deconvolve signals traveling through frequency-selective, slow fading channels. Compared with existing time-domain approaches, the ICA-F is computationally efficient and possesses fast convergence properties. Simulation results confirm the effectiveness of the proposed ICA-F. Orthogonal Frequency Division Multiplexing (OFDM) systems are widely used in wireless communications nowadays. However, OFDM systems are very sensitive to Carrier Frequency Offset (CFO). Thus, an accurate CFO compensation technique is required in order to achieve acceptable …

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Control And Topology Improvements In Half-Bridge Dc-Dc Converters, Songquan Deng Jan 2005

Control And Topology Improvements In Half-Bridge Dc-Dc Converters, Songquan Deng

Electronic Theses and Dissertations

Efficiency and transient response are two key requirements for DC-DC converters. Topology and control are two key topics in this dissertation. A variety of techniques for DC-DC converter performance improvement are presented in this work. Focusing on the efficiency issue, a variety of clamping techniques including both active and passive methods are presented after the ringing issues in DC-DC converters are investigated. By presenting the clamping techniques, a big variety of energy management concepts are introduced. The active bridge-capacitor tank clamping and FET-diode-capacitor tank clamping are close ideas, which transfer the leakage inductor energy to clamping capacitor to prevent oscillation …

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Multiple Description Distributed Image Coding With Side Information For Mobile Wireless Transmission, Min Wu, Daewon Song, Chang Wen Chen Jan 2005

Multiple Description Distributed Image Coding With Side Information For Mobile Wireless Transmission, Min Wu, Daewon Song, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

Multiple description coding (MDC) is a source coding technique that involves coding the source information into multiple descriptions, and then transmitting them over different channels in packet network or error-prone wireless environment to achieve graceful degradation if parts of descriptions are lost at the receiver. In this paper, we proposed a multiple description distributed wavelet zero tree image coding system for mobile wireless transmission. We provide two innovations to achieve an excellent error resilient capability. First, when MDC is applied to wavelet subband based image coding, it is possible to introduce correlation between the descriptions in each subband. We consider …

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Constant Quality Constrained Bit Allocation For Leaky Prediction Based Fgs Video Streaming, Jianhua Wu, Jianfei Cai, Chang Wen Chen Jan 2005

Constant Quality Constrained Bit Allocation For Leaky Prediction Based Fgs Video Streaming, Jianhua Wu, Jianfei Cai, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

Leaky prediction based FGS (Fine Granularity Scalability) can achieve better coding efficiency than the baseline FGS. However, for leaky prediction based FGS (L-FGS), constant quality constrained bit allocation, i.e., how to optimally allocate bits given the current channel bandwidth, is still an open problem. In this paper, based on the accurate R-D (Rate-Distortion) model developed in our previous work, we propose a constant quality constrained bit allocation scheme for L-FGS. The proposed scheme is a combination of offline and online processes. During the offline stage, we perform the L-FGS encoding and collect the necessary feature information. At the online stage, …

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Investigation Of High-K Gate Dielectrics And Metals For Mosfet Devices., Sriram Mannargudi Seshadri Jan 2005

Investigation Of High-K Gate Dielectrics And Metals For Mosfet Devices., Sriram Mannargudi Seshadri

Electronic Theses and Dissertations

Progress in advanced microlithography and deposition techniques have made feasible high- k dielectric materials for MOS transistors. The continued scaling of CMOS devices is pushing the Si-SiO2 to its limit to consider high-k gate dielectrics. The demand for faster, low power, smaller, less expensive devices with good functionality and higher performance increases the demand for high-k dielectric based MOS devices. This thesis gives an in-depth study of threshold voltages of PMOS and NMOS transistors using various high-k dielectric materials like Tantalum pent oxide (Ta2O5), Hafnium oxide (HfO2), Zirconium oxide (ZrO2) and Aluminum oxide (Al2O3) gate oxides. Higher dielectric constant may …

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Signal Flow Analysis, Partha P. Banerjee Jan 2005

Signal Flow Analysis, Partha P. Banerjee

Electrical and Computer Engineering Faculty Publications

Signal flow graphs are a viable alternative to block diagrammatic representation of a system. What makes signal flow graphs attractive is that certain features from graph theory can be applied to the simplification and the synthesis of complex systems.

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Functional Nanoparticles In Thin Films As Sensing Media, Elena A. Guliants, Ryan Schwarb, Hope Bearbower, James R. Gord, Christopher E. Bunker Jan 2005

Functional Nanoparticles In Thin Films As Sensing Media, Elena A. Guliants, Ryan Schwarb, Hope Bearbower, James R. Gord, Christopher E. Bunker

Electrical and Computer Engineering Faculty Publications

The combination of unique properties offered by materials on the nanoscale with the increased role of surface chemistry in nanostructured solids makes core-shell nanoparticles extremely attractive for application to "smart" thin-film coatings. Sensing properties of nanoparticle-based thin films were studied in several systems containing organic-coated semiconductor and metallic particles. In semiconductors, the interaction of organic shell and/or thin-film "matrix" with the environment results in changes in the nanoparticle's surface states, altering the optical properties of the thin film. Measuring the electrical properties of thin films composed of metallic cores with hydrocarbon shells offers another mechanism to monitor the local environment …

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Simulations Of Nanopore Formation And Phosphatidylserine Externalization In Lipid Membranes Subjected To A High-Intensity, Ultrashort Electric Pulse, Q. Hu, R. P. Joshi, K. H. Schoenbach Jan 2005

Simulations Of Nanopore Formation And Phosphatidylserine Externalization In Lipid Membranes Subjected To A High-Intensity, Ultrashort Electric Pulse, Q. Hu, R. P. Joshi, K. H. Schoenbach

Bioelectrics Publications

A combined MD simulator and time dependent Laplace solver are used to analyze the electrically driven phosphatidylserine externalization process in cells. Time dependent details of nanopore formation at cell membranes in response to a high-intensity (100kV∕cm), ultrashort (10ns) electric pulse are also probed. Our results show that nanosized pores could typically be formed within about 5ns. These predictions are in very good agreement with recent experimental data. It is also demonstrated that defect formation and PS externalization in membranes should begin on the anode side. Finally, the simulations confirm that PS externalization is a nanopore facilitated event, rather than the …

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Spatial Resolution And Processing Tradeoffs For Hydros: Application Of Reconstruction And Resolution Enhancement Techniques, David G. Long, Michael W. Spencer, Eni G. Njoku Jan 2005

Spatial Resolution And Processing Tradeoffs For Hydros: Application Of Reconstruction And Resolution Enhancement Techniques, David G. Long, Michael W. Spencer, Eni G. Njoku

Faculty Publications

Recent developments in reconstruction and resolution enhancement for microwave instruments suggest a possible tradeoff between computation, resolution, and downlink data rate based on postcollection reconstruction/resolution enhancement processing. The Hydrospheric State (HYDROS) mission is designed to measure global soil moisture and freeze/thaw state in support of weather and climate prediction, water, energy, and carbon cycle studies, and natural hazards monitoring. It will use an active and passive L-band microwave system that optimizes measurement accuracy, spatial resolution, and coverage. The active channels use synthetic aperture radar-type processing to achieve fine spatial resolution, requiring a relatively high downlink data rate and ground processor …

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A New Circularly Polarized Rectenna For Wireless Power Transmission And Data Communication, Mohammod Ali, G. Yang, Roger A. Dougal Jan 2005

A New Circularly Polarized Rectenna For Wireless Power Transmission And Data Communication, Mohammod Ali, G. Yang, Roger A. Dougal

Faculty Publications

Small distributed wireless sensors are becoming very important in many aspects of our lives. While low data rate passive sensors operate with little energy there is a need for moderate to high data rate distributed sensors for infrastructure monitoring and other applications. Such sensors will require their batteries or onboard capacitors to be charged when depleted for proper operation. In this letter, we propose a circularly polarized (CP) microstrip patch antenna that can function as a WLAN antenna in the 5.15-5.35 GHz and as a rectenna at 5.5 GHz.

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Maintaining A Balance At Undergraduate Degree Level In The Teaching Of Automation And Classical Control Systems, Eugene Coyle, Aidan O'Dwyer Jan 2005

Maintaining A Balance At Undergraduate Degree Level In The Teaching Of Automation And Classical Control Systems, Eugene Coyle, Aidan O'Dwyer

Conference papers

Advances in the past decade in the development and application of Programmable Logic Controllers (PLCs) and Automation Systems in both high technology industrial plants and in the more mainstream manufacturing sectors, has heightened the importance of ensuring that undergraduate degree programme syllabi are designed to adequately cater for the teaching and training of students in automation. Prior to this growth in automation, delivered syllabi in Control Systems on most Electrical Engineering programmes had a theoretical rigour, reflecting the mathematical nature of the topic. A major challenge currently facing departmental lecturing staff and programme coordinators is that of the design of …

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A Novel Framework For Radio Resource Management In Ieee 802.11 Wireless Lans, Mark Davis, Tristan Raimondi Jan 2005

A Novel Framework For Radio Resource Management In Ieee 802.11 Wireless Lans, Mark Davis, Tristan Raimondi

Conference papers

In this paper we address the need to characterize and quantify resource usage in IEEE 802.11 WLANs in order to support radio resource management. We present a compact and intuitive framework for performance characterization and resource utilization that is based upon the concept of MAC bandwidth components. These MAC bandwidth components are directly related to the transmission rate and serve to quantify the resource requirements associated with accessing the wireless medium. We also introduce a graphical technique for presenting these MAC bandwidth components that illustrates how WLAN stations interact in contending for access to the wireless medium. We demonstrate the …

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Power Enhancement Of An Actively Controlled Battery/Ultracapacitor Hybrid, Lijun Gao, Roger A. Dougal, Shengyi Liu Jan 2005

Power Enhancement Of An Actively Controlled Battery/Ultracapacitor Hybrid, Lijun Gao, Roger A. Dougal, Shengyi Liu

Faculty Publications

An actively controlled battery/ultracapacitor hybrid has broad applications in pulse-operated power systems. A converter is used to actively control the power flow from a battery, to couple the battery to an ultracapacitor for power enhancement, and to deliver the power to a load efficiently. The experimental and simulation results show that the hybrid can achieve much greater specific power while reducing battery current and its internal loss. A specific example of the hybrid built from two size 18650 lithium-ion cells and two 100-F ultracapacitors achieved a peak power of 132 W which is a three-times improvement in peak power compared …

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Ultra Wide-Band : State Of The Art; Implementation Of A Performance-Controllable Low-Noise Amplifier, Serigne Dia, Balwant Godora, Frederic Alicalapa, Alain Fabre Jan 2005

Ultra Wide-Band : State Of The Art; Implementation Of A Performance-Controllable Low-Noise Amplifier, Serigne Dia, Balwant Godora, Frederic Alicalapa, Alain Fabre

Turkish Journal of Electrical Engineering and Computer Sciences

Ultra Wide-Band (UWB) transmissions exhibit performances vastly superior to existing wireless systems - superlative data-rate capacity, high security, low cost, low power consumption - and are emerging as the hottest topic of research for upcoming wireless generations. This communication protocol is studied in detail, with mention of the history and estimates for the near future; the present and possible applications are mentioned; the advantages and unresolved issues are detailed; a typical UWB transceiver architecture is studied; the modulation and coding schemes are enumerated; and the possibility of long-range communication is touched upon. Finally, a new performance-controllable low-noise amplifier (LNA) destined …

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Design, Simulation And Tests Of A Low-Cost Microstrip Patch Antenna Arrays For The Wireless Communication, Gonca Çakir, Levent Sevgi̇ Jan 2005

Design, Simulation And Tests Of A Low-Cost Microstrip Patch Antenna Arrays For The Wireless Communication, Gonca Çakir, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

Typical low-cost, low-weight microstrip base station antenna arrays with beam-scanning capabilities are taken into account. In downtowns of large cities like New York, Chicago, and in historical cities like Istanbul, where high buildings are separated by narrow but densely occupied streets, antenna arrays with approximately 20°-35° beam-widths are required to complete the cellular communication coverage. To meet this requirement, new antenna arrays are designed with 35° beam-widths and 60° electronic scanning capabilities. Their characteristics are investigated both numerically and experimentally. An FDTD-based antenna simulation package (M-PATCH) is prepared, tested on canonical structures and against the literature first, for verification and …

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Turbo Codes: The Issue Of Average Union Upper Bound Under Imperfect Channel State Information In Rayleigh Fading Channels, Erhan A. İnce, Syed Amjad Ali Jan 2005

Turbo Codes: The Issue Of Average Union Upper Bound Under Imperfect Channel State Information In Rayleigh Fading Channels, Erhan A. İnce, Syed Amjad Ali

Turkish Journal of Electrical Engineering and Computer Sciences

The potential of turbo codes to demonstrate excellent performance in the region of low signal to noise ratio is now a familiar fact. The idea of turbo codes was first introduced by Berrou and was based on the clever utilization of the existing decoding mechanism of BCJR with a change in the encoder by introducing feedback and an interleaver in the overall scheme. Since then, these powerful forward error correcting codes have attained a significant attention and have either replaced or have become a sturdy candidate for many applications in this era of modern communication systems. So far, a lot …

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Efficient Capacity-Based Antenna Selection For Mimo Systems, Michael A. Jensen, Matthew L. Morris Jan 2005

Efficient Capacity-Based Antenna Selection For Mimo Systems, Michael A. Jensen, Matthew L. Morris

Faculty Publications

The achieved capacity of the multiple-input-multiple-output wireless channel is typically dependent on the array configurations at the transmitter and receiver. Maximizing system capacity or throughput therefore requires that the arrays adapt to changing channel conditions, which may be accomplished by selecting an appropriate subset of available antenna elements for connection to the electronic transmit and receive modules. This work presents algorithms, derived using relatively straightforward information theoretic considerations, for efficiently and effectively selecting the antenna elements. Computational examples using a realistic channel model for indoor environments illustrate the performance of the techniques.

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Network Model For Mimo Systems With Coupled Antennas And Noisy Amplifiers, Michael A. Jensen, Matthew L. Morris Jan 2005

Network Model For Mimo Systems With Coupled Antennas And Noisy Amplifiers, Michael A. Jensen, Matthew L. Morris

Faculty Publications

This work presents a framework for the analysis of mutually-coupled antennas in a multiple-input multiple-output system. The approach uses network theory to formulate the transfer matrix relating the signals input to the transmit antennas to the signals at the output of the receiver front end. This transfer function includes the coupled transmit and receive antennas, the multipath propagation channel, the receiver matching network, and a realistic noise model for the receive amplifiers. Application of the formulation to coupled dipole antennas characterized using full-wave electromagnetic analysis illustrates the performance gains possible from matching the coupled antenna/receive amplifier subsystem for minimum noise …

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Effects Of Focusing-Beam Field Variations On The Stability Of Laser Oscillators, Pitak Chenkosol, Lee W. Casperson Jan 2005

Effects Of Focusing-Beam Field Variations On The Stability Of Laser Oscillators, Pitak Chenkosol, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Semiclassical models for the dynamical behavior of single-longitudinal-mode, homogeneously broadened, unidirectional ring-laser oscillators have long been available. However, in most of these models the beam's cross section is assumed to be independent of longitudinal position in the laser, while in practical laser systems it is common for the diameter to vary with position. A model for lasers with focusing-beam field variations is developed here. Linear stability analysis shows that higher values of excitation are required to reach the type 1 instability threshold for lasers with longitudinal variations of the beam diameter than for the uniform plane-wave laser model.

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An Experimental Analysis Of The Call Capacity Of Ieee 802.11b Wireless Local Area Networks For Voip Telephony, Brian Keegan Jan 2005

An Experimental Analysis Of The Call Capacity Of Ieee 802.11b Wireless Local Area Networks For Voip Telephony, Brian Keegan

Masters

The use of the Internet to make phone calls is growing in popularity as the Voice over Internet protocol (VoIP) allows users to make phone calls virtually free of charge. The increased uptake of broadband services by domestic users will further increase the use of VoIP telephony. Furthermore, the emergence of low cost wireless networks (namely IEEE 802.11a/b/g WLANs) is expected to bring wireless VoIP into the mainstream. As the number of wireless hotspots increases more users will want to use VoIP calls wherever possible by connecting to open access points (AP). A major concern with VoIP is Quality of …

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Refractive Indices Of Liquid Crystals And Their Applications In Display And Photonic Devices, Jun Li Jan 2005

Refractive Indices Of Liquid Crystals And Their Applications In Display And Photonic Devices, Jun Li

Electronic Theses and Dissertations

Liquid crystals (LCs) are important materials for flat panel display and photonic devices. Most LC devices use electrical field-, magnetic field-, or temperature-induced refractive index change to modulate the incident light. Molecular constituents, wavelength, and temperature are the three primary factors determining the liquid crystal refractive indices: ne and no for the extraordinary and ordinary rays, respectively. In this dissertation, we derive several physical models for describing the wavelength and temperature effects on liquid crystal refractive indices, average refractive index, and birefringence. Based on these models, we develop some high temperature gradient refractive index LC mixtures for photonic applications, such …

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Discrete Wave Propagation In Quadratically Nonlinear Media, Robert Iwanow Jan 2005

Discrete Wave Propagation In Quadratically Nonlinear Media, Robert Iwanow

Electronic Theses and Dissertations

Discrete models are used in describing various microscopic phenomena in many branches of science, ranging from biology through chemistry to physics. Arrays of evanescently coupled, equally spaced, identical waveguides are prime examples of optical structures in which discrete dynamics can be easily observed and investigated. As a result of discretization, these structures exhibit unique diffraction properties with no analogy in continuous systems. Recently nonlinear discrete optics has attracted a growing interest, triggered by the observation of discrete solitons in AlGaAs waveguide arrays reported by Eisenberg et al. in 1998. So far, the following experiments involved systems with third order nonlinearities. …

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