Dissertations / Theses on the topic 'Polarization noise'

Thesis (Ph. D.)--University of Oregon, 2002.
Typescript. Includes vita and abstract. Includes bibliographical references (leaves 138-142). Also available for download via the World Wide Web; free to University of Oregon users.

Polarimetric systems design has seen recent utilization of linear systems theory for system descriptions. Although noise optimal systems have been shown, bandwidth performance has not been addressed in depth generally and is particularly lacking for Mueller matrix (active) polarimetric systems. Bandwidth must be considered in a systematic way for remote sensing polarimetric systems design. The systematic approach facilitates both understanding of fundamental constraints and design of higher bandwidth polarimetric systems. Fundamental bandwidth constraints result in production of polarimetric "artifacts" due to channel crosstalk upon Mueller matrix reconstruction. This dissertation analyzes bandwidth trade-offs in spatio-temporal channeled Mueller matrix polarimetric systems. Bandwidth is directly related to the geometric positioning of channels in the Fourier (channel) space, however channel positioning for polarimetric systems is constrained both physically and by design parameters like domain separability. We present the physical channel constraints and the constraints imposed when the carriers are separable between space and time. Polarimetric systems are also constrained by noise performance, and there is a trade-off between noise performance and bandwidth. I develop cost functions which account for the trade-off between noise and bandwidth for spatio-temporal polarimetric systems. The cost functions allow a systems designer to jointly optimize systems with good bandwidth and noise performance. Optimization is implemented for a candidate spatio-temporal system design, and high temporal bandwidth systems resulting from the optimization are presented. Systematic errors which impact the bandwidth performance and mitigation strategies for these systematic errors are also presented. Finally, a portable imaging Mueller matrix system is built and analyzed based on the theoretical bandwidth analysis and system bandwidth optimization. Temporal bandwidth performance is improved by 300% over a conventional dual rotating retarder Mueller matrix polarimeter. Reconstruction results from the physical instrument are presented, and issues with the implemented system design are discussed.

This master thesis deals with the possibility of separation of useful signal from noise using polarization of laser radiation. This thesis is structured into 5 thematic units. The first unit is focused on laser radiation and its properties. The second part contains a deeper focus on the polarization of radiation, its description and the possibilities of measuring the polarization states. The third part of the thesis is devoted to the design of the measuring chains and identification of used elements. Chapter four contains measurement of status of the polarization and its results. The last chapter analyzes particular measuring chains outputs according to their spectral characteristics.

In our work the analysis of electrical and noise characteristics of piezoceramic acoustic emission sensors is accomplished. The objective of our work is to analyze and optimize the signal-to-noise ratio. The starting point is the explanation of the noise origin in the acoustic emission sensors. The voltage fluctuation is caused by the dipole vibrations due to their interaction with phonons. The frequencies of dipoles vibrations have statistical distribution and the total energy of these vibrations is proportional to the temperature. The statistical distribution of vibration frequencies leads to the origination of the 1/f type noise spectral density. The interaction between the phonons and electric dipoles is characterized by the imaginary part of susceptibility which is related to the transformation of electric energy to the mechanical energy of vibrations. This process is irreversible and this forms important theoretical question whether the Callen-Welton fluctuation dissipation theorem could be used for the description of fluctuation processes in the acoustic emission sensors. In our work the influence of the real and imaginary part of the susceptibility on the noise and electrical characteristics is solved, the dissipation of electrical energy characterized by the imaginary part of susceptibility is described and the connection between the imaginary part of susceptibility and the noise power spectral density is discussed. Due to the fact that these processes originate in the interaction between electrical dipoles and phonons, we give account of the temperature dependencies of equivalent series resistance and power spectral density of noise voltage, respectively. Piezoceramics stiffness contribute significantly to the resonance creation hence the pressure influence on the sensor noise characteristics was studied. The signal-to-noise ration improvement requires the piezoceramic sample diameter increase for its constant thickness. The ratio of the noise spectral density and sensitivity is independent on the sample thickness. The noise voltage is proportional to the square root of spectral density and frequency bandwidth that is why for the high signal-to-noise ratio it is necessary to minimize the signal amplifier frequency bandwidth. The noise voltage power spectral density increases with the temperature while the activation energy is 20 meV for the temperature 300 K, and 80 meV for the temperature 400 K, respectively. The power spectral density of planar oscillations decreases with increasing pressure and simultaneously the resonant frequency increases. The bandwidth of the normalized spectral density increases with the pressure for the planar oscillations while is invariable for the thickness oscillations. For the examination of the influence of the piezoceramic electrical polarization on the electrical and noise characteristics the experimental study of these dependencies was accomplished for samples without polarization, and samples polarized by electric field EP = 500V/mm and 1000V/mm, respectively. The samples without polarization show the noise of 1/f type only which corresponds to the Callen-Welton fluctuation dissipation theorem. The polarization leads to the generation of planar and thickness oscillations and the power spectral density of voltage fluctuation on the electrodes is proportional to the temperature, and inversely proportional to the imaginary part of permittivity, to the sample area S, and the frequency f.

Orientador: Prof. Dr. Luciano Soares da Cruz
Coorientador: Prof. Dr. Marcelo Matinelli
Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Física, Santo André, 2018.
Estados da luz com propriedades não-clássicas são ferramentas essenciais para o desenvolvimento de diversas áreas, como Informação Quântica, Metrologia, Computação Quântica etc. Neste trabalho geramos e medimos estados com compressão de ruído de polarização. Para isto, utilizamos como fonte de estados coerentes um laser de Titânio-Sa?ra, que equipamos com um sistema de controle ativo de modo e frequência. Com este sistema, podemos sintonizar o laser às transições da estrutura hiper?na do Rubídio e, através da interação do feixe com vapor atômico de Rb, promover a autorrotação de polarização. Este fenômeno não-linear faz com que a elipse de polarização do feixe gire, alterando assim as propriedades do seu ruído, podendo inclusive gerar compressão. Investigamos a dependência de parâmetros como ângulo relativo entre campo e oscilador local, potência incidiente no vapor atômico e frequência de análise na geração de compressão na linhaD1 do isótopo 87 do Rubídio sobre o operador de Stokes ¿S2. Medimos (2.7 ± 0.2) dB de compressão na transição 2?2 e (5.0± 0.1) dB na 2?1.
Light states with non-classical properties are essential tools for the development of several areas, such as Quantum Information, Metrology, Quantum Computation etc. In this work, we generated and measured squeezed polarization states. For this purpose, we used a Titanium-Sapphire laser, which we built an active control system for mode and frequency. It can access the transitions of the hyperfine structure of Rubidium and promote polarization self rotation from the interaction between laser beam and vapour atomic of Rb. This non-linear phenomenon rotates the beam polarization ellipse, changing the properties of its noise and may generating squeezing. We investigated the squeezing generation dependence on parameters as relative angle between field and local oscillator, light power on atomic vapour cell and analysis frequency. We looked for line D1 of the isotope 87 of the rubidium on the operator of Stokes ¿S2 and found (2.7± 0.2) dB at the transition 2 ? 2 and (5.0± 0.1) dB at the 2? 1.

PILOT, pour Polarized instrument for Long Wavelength Observation od the Tenuous interstellar medium, est une expérience d'astrophysique embarquée sous ballon stratosphérique dont l'objectif principal est la mesure de l'émission polarisée de la lumière par les poussières du milieu interstellaire. Cette expérience permettra la cartographie du champ magnétique galactique à une résolution de l'ordre de la minute d'arc à une longueur d'onde de 240 µm (1.2 THz). La détection de la polarisation est réalisée à l'aide d'un polariseur placé à 45° dans le faisceau, le décomposant en deux composantes polarisées orthogonales chacune détectées par quatre matrices de 256 bolomètres, et d'une lame demi-onde rotative. Les observations de PILOT s'inscrivent en complément des observations effectuées à l'aide du satellite Planck, avec une meilleure résolution angulaire, et en complément des observations en polarisation menées au sol avec des instruments comme NIKA2 installé sur le télescope de 30m de l'IRAM. Cette thèse se divise en trois parties, la première étant consacrée à la présentation du contexte scientifique qui entoure l'instrument ainsi qu'à la présentation de l'instrument et des deux campagnes de vol ayant eu lieu à Timmins au Canada et Alice Spring en Australie. La deuxième partie se focalise sur les performances en vol de PILOT et la troisième partie présente le pipeline mis en place pour le traitement des données ainsi que les premières cartes en polarisation obtenues
PILOT, for Polarized instrument for Long Wavelength Observation of the Tenuous interstellar medium) is a stratospheric balloon astrophysics experiment whose main objective is the measurement of the polarized emission of light by the dust of the interstellar medium. This experiment will allow the mapping of the galactic magnetic field to a resolution of the order of one arcmin at a wavelength of 240 µm (1.2 THz). The polarization detection is carried out using a polarizer placed at 45° in the beam, decomposing it into two orthogonal polarized components each detected by four matrices of 256 bolometers, and a half-wave plate. The PILOT observations are in addition to the observations made using the Planck satellite, with better angular resolution, and in addition to polarization observations conducted on the ground with instruments such as NIKA2 installed on the IRAM 30m telescope. This thesis is divided into three parts, the first being devoted to the presentation of the scientific context surrounding the instrument as well as to the presentation of the instrument and the two flying campaigns that took place in Timmins in Canada and Alice Spring in Australia. The second part focuses on the inflight performance of PILOT and the third part presents the pipeline set up for data processing and the first polarization maps obtained

Poptávka ze strany vesmírného výzkumu, zdravotnictví a bezpečnostního průmyslu způsobila v posledních letech zvýšený zájem o vývoj materiálů pro detekci a zobrazování vysokoenergetického záření. CdTe a jeho slitina CdZnTe. jsou polovodiče umožnují detekci záření o energiích v rozsahu 10 keV až 500 keV. Šířka zakázaného pásma u CdTe / CdZnTe je 1.46 -1.6 eV, což umožňuje produkci krystalů o vysoké rezistivitě (10^10-10^11 cm), která je dostačující pro použití CdTe / CdZnTe při pokojové teplotě. V mé práci byly zkoumány detektory CdTe/CdZnTe v různých stádiích jejich poruchovosti. Byly použity velmi kvalitní spektroskopické detektory, materiál s nižší rezistivitou a výraznou polarizací, detektory s asymetrií elektrických parametrů kontaktů a teplotně degenerované vzorky. Z výsledků analýzy nízkofrekvenčního šumu je patrný obecný závěr, že zvýšená koncentrace defektů způsobí změnu povahy původně monotónního spektra typu 1/f na spektrum s výrazným vlivem generačně-rekombinačních procesů. Další výrazná vlastnost degenerovaných detektorů a detektorů nižší kvality je nárůst spektrální hustoty šumu typu 1/f se vzrůstajícím napájecím napětí se směrnicí výrazně vyšší než 2. Strukturální a chemické analýzy poukázaly, že teplotní generace detektorů způsobuje difuzi kovu použitého při kontaktování a stopových prvků hlouběji do objemu krystalu. Část mé práce je věnována modifikaci povrchu svazkem argonových iontů a jejímu vlivu na chemické složení a morfologii povrchu.

Les radars à synthèse d’ouverture (RSO) polarimétriques sont devenus incontournables dans le domaine de la télédétection, grâce à leur zone de couverture étendue, ainsi que leur capacité à acquérir des données dans n’importe quelles conditions atmosphériques de jour comme de nuit. Au cours des trois dernières décennies, plusieurs RSO polarimétriques ont été utilisés portant une variété de modes d’imagerie, tels que la polarisation unique, la polarisation double et également des modes dits pleinement polarimétriques. Grâce aux recherches récentes, d’autres modes alternatifs, tels que la polarisation hybride et compacte, ont été proposés pour les futures missions RSOs. Toutefois, un débat anime la communauté de la télédétection quant à l’utilité des modes alternatifs et quant au compromis entre la polarimétrie double et la polarimétrie totale. Cette thèse contribue à ce débat en analysant et comparant ces différents modes d’imagerie RSO dans une variété d’applications, avec un accent particulier sur la surveillance maritime (la détection des navires et de marées noires). Pour nos comparaisons, nous considérons un paramètre fondamental, appelé le degré de polarisation (DoP). Ce paramètre scalaire a été reconnu comme l’un des paramètres les plus pertinents pour caractériser les ondes électromagnétiques partiellement polarisées. A l’aide d’une analyse statistique détaillée sur les images polarimétriques RSO, nous proposons des estimateurs efficaces du DoP pour les systèmes d’imagerie cohérente et incohérente. Ainsi, nous étendons la notion de DoP aux différents modes d’imagerie polarimétrique hybride et compacte. Cette étude comparative réalisée dans différents contextes d’application dégage des propriétés permettant de guider le choix parmi les différents modes polarimétriques. Les expériences sont effectuées sur les données polarimétriques provenant du satellite Canadian RADARSAT-2 et le RSO aéroporté Américain AirSAR, couvrant divers types de terrains tels que l’urbain, la végétation et l’océan. Par ailleurs nous réalisons une étude détaillée sur les potentiels du DoP pour la détection et la reconnaissance des marées noires basée sur les acquisitions récentes d’UAVSAR, couvrant la catastrophe de Deepwater Horizon dans le golfe du Mexique
Polarimetric Synthetic Aperture Radar (SAR) systems have become highly fruitful thanks to their wide area coverage and day and night all-weather capabilities. Several polarimetric SARs have been flown over the last few decades with a variety of polarimetric SAR imaging modes; traditional ones are linear singleand dual-pol modes. More sophisticated ones are full-pol modes. Other alternative modes, such as hybrid and compact dual-pol, have also been recently proposed for future SAR missions. The discussion is vivid across the remote sensing society about both the utility of such alternative modes, and also the trade-off between dual and full polarimetry. This thesis contributes to that discussion by analyzing and comparing different polarimetric SAR modes in a variety of geoscience applications, with a particular focus on maritime monitoring and surveillance. For our comparisons, we make use of a fundamental, physically related discriminator called the Degree of Polarization (DoP). This scalar parameter has been recognized as one of the most important parameters characterizing a partially polarized electromagnetic wave. Based on a detailed statistical analysis of polarimetric SAR images, we propose efficient estimators of the DoP for both coherent and in-coherent SAR systems. We extend the DoP concept to different hybrid and compact SAR modes and compare the achieved performance with different full-pol methods. We perform a detailed study of vessel detection and oil-spill recognition, based on linear and hybrid/compact dual-pol DoP, using recent data from the Deepwater Horizon oil-spill, acquired by the National Aeronautics and Space Administration (NASA)/Jet Propulsion Laboratory (JPL) Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR). Extensive experiments are also performed over various terrain types, such as urban, vegetation, and ocean, using the data acquired by the Canadian RADARSAT-2 and the NASA/JPL Airborne SAR (AirSAR) system

Cette these, menee dans le cadre d'un travail sur la transmission d'informations par voie optique, comporte deux parties; la premiere traite du bruit de polarisation introduit par l'atmosphere au repos ou en ecoulement; la seconde partie traite du couplage par champ evanescent dans les fibres monomodes

Man-Hong Cheung.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2004.
Includes bibliographical references (leaves 88-97).
Abstracts in English and Chinese.
Chapter Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Drivers for Advanced Optical Performance Monitoring (OPM) Techniques --- p.1
Chapter 1.2 --- OPM： Definition and Significance --- p.4
Chapter 1.3 --- The Broad Spectrum of OPM --- p.5
Chapter 1.3.1 --- Signal Loss Monitoring --- p.7
Chapter 1.3.2 --- Signal Alignment Monitoring --- p.7
Chapter 1.3.3 --- Signal Quality Monitoring --- p.7
Chapter 1.4 --- Classification of OPM Techniques --- p.9
Chapter 1.4.1 --- Time Domain vs. Frequency Domain Monitoring --- p.9
Chapter 1.4.2 --- Analog Parameter vs. Digital Parameter Monitoring --- p.9
Chapter 1.4.3 --- Three-Tier OPM --- p.11
Chapter 1.5 --- Challenges and Requirements of OPM Techniques --- p.13
Chapter 1.6 --- Thesis Outline --- p.15
Chapter Chapter 2 --- Review on OSNR and PMD Monitoring --- p.16
Chapter 2.1 --- Optical Signal-to-Noise-Ratio (OSNR) Monitoring --- p.16
Chapter 2.2 --- Out-of-band OSNR Monitoring Techniques --- p.17
Chapter 2.2.1 --- Optical Spectral Analysis --- p.17
Chapter 2.2.2 --- Arrayed Waveguide Grating/Tunable Filter Assisted Power Measurements --- p.19
Chapter 2.2.3 --- RF Spectral Analysis --- p.20
Chapter 2.2.3.1 --- Low/High RF Noise Monitoring --- p.20
Chapter 2.2.3.2 --- Subcarrier CNR Correlation --- p.20
Chapter 2.3 --- In-band OSNR Monitoring Techniques --- p.20
Chapter 2.3.1 --- Polarization-Assisted OSNR Monitoring --- p.21
Chapter 2.3.1.1 --- Polarization Extinction Method --- p.21
Chapter 2.3.1.2 --- Polarization-Nulling --- p.22
Chapter 2.3.1.3 --- Degree-of-Polarization (DOP) Based OSNR Monitoring --- p.23
Chapter 2.3.2 --- In-band RF Spectral Analysis --- p.24
Chapter 2.3.2.1 --- Orthogonal Delayed Homodyne Method --- p.24
Chapter 2.3.2.2 --- Half Clock Frequency Constellation Monitoring
Chapter 2.3.3 --- Interferometric Approach --- p.26
Chapter 2.3.4 --- Nonlinear Method --- p.26
Chapter 2.4 --- Polarization-Mode-Dispersion (PMD) Monitoring --- p.27
Chapter 2.4.1 --- Degree-of-Polarization (DOP) Monitoring --- p.29
Chapter 2.4.2 --- RF Spectral Analysis --- p.31
Chapter 2.4.2.1 --- PMD-Induced RF Dip Power Measurement --- p.31
Chapter 2.4.2.2 --- Subcarriei-Based RF Power Fading Measurement --- p.32
Chapter 2.4.3 --- "Eye-Opening, Penalty Monitoring" --- p.33
Chapter 2.4.4 --- Phase Diversity Detection --- p.33
Chapter 2.4.5 --- Arrival Time Measurement of Polarization-Scrambled Light --- p.34
Chapter 2.4.6 --- Nonlinear Method --- p.34
Chapter 2.5 --- Summary of different OSNR and PMD Monitoring Methods . --- p.34
Chapter Chapter 3 --- On Robustness of In-band Polarization-Assisted OSNR Monitoring Techniques against PMD --- p.36
Chapter 3.1 --- Introduction --- p.36
Chapter 3.2 --- Impact of PMD on Polarization-Nulling --- p.37
Chapter 3.2.1 --- Numerical Results using Ideal Rectangular Pulse --- p.40
Chapter 3.2.2 --- Numerical and Experimental Results using Super Gaussian Pulse --- p.43
Chapter 3.3 --- Impact of PMD on DOP-based OSNR Monitoring --- p.46
Chapter 3.3.1 --- Numerical and Experimental Results Using Ideal Rectangular and Super-Gaussian Pulses --- p.46
Chapter 3.4 --- Impact of PMD on Orthogonal Delayed-Homodyne Method --- p.49
Chapter 3.5 --- Summary --- p.53
Chapter Chapter 4 --- PMD-Insensitive OSNR Monitoring Based on Polarization-Nulling with Off-Center Narrowband Filtering --- p.54
Chapter 4.1 --- Introduction --- p.54
Chapter 4.2 --- Previously Proposed Schemes based on Polarization-Nulling --- p.55
Chapter 4.2.1 --- Improved Polarization-Nulling Technique --- p.55
Chapter 4.2.2 --- Periodic Polarization Encoding Technique --- p.57
Chapter 4.3 --- A new PMD-Insensitive OSNR Monitoring Technique based on Polarization-Nulling with Off-Center Narrowband Filtering --- p.58
Chapter 4.3.1 --- Principle of Proposed Technique --- p.59
Chapter 4.3.2 --- Theoretical Calculations --- p.62
Chapter 4.3.3 --- Experimental Results --- p.65
Chapter 4.3.4 --- "Effects of Filter Position, Filter Bandwidth, and Filter Detuning" --- p.69
Chapter 4.4 --- Summary --- p.71
Chapter Chapter 5 --- Simultaneous OSNR and PMD Monitoring using Polarization Techniques --- p.72
Chapter 5.1 --- Introduction --- p.72
Chapter 5.2 --- Previously Proposed Scheme --- p.72
Chapter 5.3 --- Simultaneous OSNR and PMD Monitoring by Enhanced RF Spectral Analysis --- p.74
Chapter 5.3.1 --- Proposed Scheme --- p.75
Chapter 5.3.2 --- Experimental Results --- p.77
Chapter 5.4 --- DOP-based Simultaneous OSNR and PMD Monitoring --- p.80
Chapter 5.4.1 --- Principle of Operation --- p.81
Chapter 5.4.2 --- Experimental Results --- p.82
Chapter 5.5 --- Summary --- p.84
Chapter Chapter 6 --- Conclusions and Future Works --- p.85
Chapter 6.1 --- Summary of the Thesis --- p.85
Chapter 6.2 --- Future Works --- p.86
Bibliography --- p.88
Appendix - List of publications --- p.97

碩士
國立成功大學
電腦與通信工程研究所
96
Utilizing the property that the light can transmit with two mutually orthogonal states of polarization (SOPs) in single mode fibers, we propose the optical code-division multiple-access (OCDMA) encoder/decoder (codec) structure based on polarization beam splitters (PBSs) and arrayed waveguide gratings (AWGs) and utilize the concept of polarization diversity to implement spectral-polarization coding (SPC) with incoherent optical source. The signature code of users in the system is addressed by the Walsh-Hadamard matrix. And according to different transmitted bits (1 or 0), the specific signature code would accompany with a set of contrary orthogonal SOPs. 　　At the decoder, the received signal, which includes the SOP information to each wavelength, is took out the corresponding wavelengths matched with encoding scheme then split into two orthogonal SOPs with PBS. Finally, the transmitted signals from users are determined by the double balance-difference detection. Due to the Walsh-Hadamard matrix is an orthogonal matrix, the multiple access interference (MAI) is eliminated in theory. Moreover, the SPC scheme is superior to the spectral-amplitude coding system with Walsh-Hadamard code and results in suppressing effectively phase-induced intensity noise (PIIN) and boosting the signal-to-noise ratio (SNR). Hence, the number of simultaneous active users could be also upgrade. 　　To sum up, although embedded polarization diversity technique over AWG-based codec in OCDMA network, the performance would be improved without any depolarization device.

The polarization response such as ferroelectric and ferroelastic switching in ferroelectrics is the important feature for ferroelectric and electromechanical applications. In polycrystalline form ferroelectrics, effects of the microstructural parameters such as texture, grain size, and residual stress are there and have not fully been understood. Among these effects, (1) the origin of grain size effects on ferroelastic switching, (2) mechanical stress effects on polarization switching, and (3) ferroelectric switching kinetics and the relationship to grain boundaries are investigated.
Firstly, the microscopic origin of ferroelastic switching suppression in smaller grains is discovered using a microscopic probing technique (piezoresponse force microscopy). It is demonstrated that there is no independent grain size effect on ferroelastic switching; the grain size affects the domain structure in a grain, and the domain structure plays an important role in the ferroelastic switching suppression. This result suggests that the grain size is not an independent critical parameter for the electromechanical property degradation in a grain < 1 m as the ferroelastic switching is a dominant component for the electromechanical property.
The study about the mechanical stress effects on the electric field induced polarization switching rationalizes the emergence of the electric field induced low-symmetry phases observed in tetragonal Pb(Zr,Ti)O3 and BaTiO3 ceramics after poling. It is demonstrated that a shear stress plays an important role in stabilizing the monoclinic phase in Pb(Zr,Ti)O3 whereas a normal stress along the polarization axis is a key for the monoclinic phase in BaTiO3 with a thermodynamic approach. It is suggested that the fraction of the low-symmetry phase, which is important for the large electromechanical property, can be engineered by applying an appropriate stress.
For the work about ferroelectric switching kinetics, the first direct Barkhausen noise associated with ferroelectric switching is measured. The domain switching time is quantified by the frequency of the Barkhausen noise. It is discovered that the dominant domain wall pinning site is grain boundaries based on the domain wall jump distance between pinning sites calculated from the switching time. This result suggests that the technique is a good tool for understanding the relationship between microstructure – domain wall kinetics.
In sum, the mechanisms of the polarization switching suppression due to domain structure and grain boundaries, and the emergence of the low symmetry phases due to stresses are revealed. These discoveries facilitate further improvements of the device performances with engineering the domain structure, grain boundaries and residual stress.

Poon, Sin Yau = 光子在噪聲環境中的解糾纏 / 潘善柔.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2008.
Includes bibliographical references (leaves 101-110).
Abstracts in English and Chinese.
Poon, Sin Yau = Guang zi zai zao sheng huan jing zhong de jie jiu chan / Pan Shanrou.
Chapter 1 --- Introduction --- p.1
Chapter 2 --- Review on entanglement theory --- p.4
Chapter 2.1 --- Pure state entanglement --- p.4
Chapter 2.2 --- Mixed state entanglement --- p.7
Chapter 2.3 --- Positive partial transposition (PPT) criterion --- p.9
Chapter 2.4 --- Negativity of pTA --- p.9
Chapter 2.4.1 --- Basic properties --- p.10
Chapter 2.4.2 --- Comparison with concurrence --- p.11
Chapter 2.5 --- Entanglement witness --- p.12
Chapter 2.6 --- Inseparability criterion based on uncertainty relations --- p.13
Chapter 2.7 --- Limitations of the PPT criterion --- p.14
Chapter 2.8 --- Other manifestations of entanglement --- p.16
Chapter 2.8.1 --- Non-classicality by negative P-representation --- p.16
Chapter 2.8.2 --- Non-locality by violation of Bell´ةs inequality --- p.17
Chapter 3 --- Quantum decoherence: General considerations for open systems --- p.22
Chapter 3.1 --- A master equation approach --- p.22
Chapter 3.1.1 --- Master equation in Markovian channels --- p.25
Chapter 3.2 --- Negativity as a monotone in Markovian systems --- p.26
Chapter 3.3 --- Finite time disentanglement --- p.29
Chapter 3.4 --- Non-classicality of harmonic oscillating systems in finite temperature baths --- p.32
Chapter 4 --- Disentanglement dynamics of two-mode Gaussian states --- p.36
Chapter 4.1 --- Two-mode Gaussian states: General descriptions --- p.36
Chapter 4.1.1 --- Covariance matrices and symplectic eigenvalues --- p.37
Chapter 4.1.2 --- Squeezed states as a source of entanglement --- p.39
Chapter 4.2 --- Eigenvalues and eigenvectors of pTA --- p.41
Chapter 4.3 --- Physical interpretation of negativity --- p.43
Chapter 4.4 --- Disentanglement of two-mode squeezed states in damping and amplifying environment --- p.47
Chapter 4.4.1 --- Block structures of pTA in Fock space --- p.47
Chapter 4.4.2 --- Analytic solution of p in position space --- p.49
Chapter 4.4.3 --- Evolution of eigenvalues and eigenvectors of pTA --- p.51
Chapter 4.4.4 --- Robust structure of entanglement witness --- p.56
Chapter 4.5 --- Beam splitter as a model for thermal damping of initial Gaussian states --- p.59
Chapter 4.6 --- Evolution of entanglement of a damped parametric oscillator --- p.63
Chapter 4.6.1 --- Eigenvalues and Eigenvectors of pTA --- p.64
Chapter 4.6.2 --- Negativity and sub-negativity --- p.66
Chapter 4.7 --- Dissipation in baths with both amplitude and phase damping --- p.68
Chapter 4.8 --- Loss of nonlocality: An optimized Bell's inequality approach --- p.69
Chapter 5 --- Disentanglement via polarization mode dispersion --- p.73
Chapter 5.1 --- Review on polarization mode dispersion --- p.73
Chapter 5.2 --- A model for stochastic polarization mode dispersion --- p.75
Chapter 5.3 --- General description of two-photon states --- p.78
Chapter 5.4 --- Disentanglement of two-photon states in separate fibers --- p.81
Chapter 5.4.1 --- Polarization negativity and frequency negativity --- p.83
Chapter 5.4.2 --- Polarization disentanglement --- p.84
Chapter 5.4.3 --- Frequency disentanglement --- p.85
Chapter 5.5 --- Disentanglement of two-photon states in a common fiber --- p.86
Chapter 5.5.1 --- Polarization disentanglement of the singlet state --- p.90
Chapter 5.5.2 --- Frequency entanglement of the singlet state --- p.91
Chapter 5.6 --- Non-Markovian channels --- p.92
Chapter 6 --- Conclusion --- p.99
Bibliography --- p.101
Chapter A --- CHSH Inequality for bipartite two level systems --- p.111
Chapter B --- Transformation from general two-mode Gaussian to double Gaussian product --- p.113
Chapter C --- Time evolution of general real symmetric two-mode Gaussian density operator --- p.116
Chapter D --- Time evolution of a damped parametric oscillator --- p.119
Chapter E --- Optimal Bell values for a damped TMSV in pseudo-spin formalism --- p.123
Chapter F --- Derivation of master equation for two-photon states --- p.125
Chapter G --- Solution of master equation for two-photon states --- p.127
Chapter G.1 --- Evolution of two-photon states in separate fibers --- p.127
Chapter G.2 --- Evolution of two-photon state in a common fiber --- p.129

碩士
國立成功大學
電腦與通信工程研究所
93
Due　to　optical　code-division　multiple-access　(OCDMA)　techniques　allow　multiple　users　access　the　network　asynchronously　and　simultaneously,　they　are　suitable　applications　in　local　area　networks　(LANs).　With　regard　to　spectral-amplitude-coding　(SAC)　technology,　the　maximum　number　of　serviceable　wavelengths　dictates　the　code　length　for　coding,　i.e.,　the　number　of　users　can　be　accommodated　in　the　network.　Therefore,　such　spectrum-sliced　systems　are　straining　to　accommodate　either　smaller　wavelength　spacing　or　wider　wavelength　ranges　in　order　to　continue　the　growth　in　capacity.　Although　the　data　bits　can　be　recovered　without　the　influence　of　multiple　access　interference　(MAI)　theoretically　in　SAC-OCDMA　systems,　there　is　still　phase-induced　intensity　noise　(PIIN)　which　can　deteriorate　system　performance　especially　when　a　large　number　of　users　are　involved. 　　In　this　thesis,　we　propose　a　multilevel　SAC-OCDMA　system　based　on　the　pseudo-orthogonality　of　Hadamard　code　properly　written　in　the　fiber　Bragg　Gratings　(FBGs).　Each　encoder/decoder　pair　is　shared　by　two　users.　In　our　proposal,　not　merely　the　number　of　encoder/decoder　pairs　but　also　the　required　code　length　can　be　reduced　to　half　as　compared　with　previous　systems　at　the　same　number　of　subscribers.　Since　we　use　multilevel　spectral　coding,　PIIN　induced　by　high　intensities　deteriorates　the　system　performance　more　than　low　intensities.　To　suppress　PIIN,　users　sharing　the　same　encoder　transmit　signals　on　mutually　orthogonal　polarizations,　and　a　new　receiver　structure　with　multiple　balanced　detectors　(MBD)　is　employed.　The　first　method　utilizes　the　fact　that　PIIN　vanishes　if　the　polarizations　of　signals　are　mutually　orthogonal.　The　other　applies　the　idea　that　less　power　of　optical　signals　impinging　on　the　photodetector　induces　less　PIIN　power. 　　To　sum　up,　the　proposed　system　can　reduce　the　code　length　and　the　number　of　codecs,　and　achieves　better　system　performance　which　is　mainly　limited　by　PIIN.