Typescript (photocopy). / Digitized by Kansas Correctional Industries

Arid and semi-arid ecosystems of the southwestern U.S. are experiencing major changes that have profound impacts for community structure and ecosystem function. First, these ecosystems are experiencing dramatic shifts in vegetation composition as a result of the invasion of non-native species. Second these ecosystems are predicted to undergo substantial shifts in climate regime, which include increases in the variability and frequency of extreme temperature and precipitation events. It is not well understood how these current and predicted changes will affect the physiological performance of different plant types in arid and semi-arid ecosystems. To address the effect of these changes, this dissertation focused on the photosynthetic response of a native and non-native grass species, and dominant shrub species to precipitation across contrasting soil surfaces in southeastern Arizona. The native and non-native grasses were exposed to wet and dry seasonal precipitation and responses to precipitation events ('pulses') were measured over the course of a summer growing season. To gain a mechanistic understanding of these patterns, the biochemical and diffusion limitations to photosynthetic function were measured over the course of a pulse period. Building on this foundation, natural stands of the non-native grass species were exposed to sequences of different sized pulse events. The physiological performance of a dominant shrub species, Larrea tridentata, was measured in order to determine the biochemical and diffusional constraints to photosynthetic function across seasons and contrasting soil surfaces. The results showed that leaf area development of these grass species affects water availability and time lags in photosynthetic response. Initial soil moisture conditions across contrasting soil surfaces influence the magnitude of photosynthetic response in grasses. Large photosynthetic responses of the non-native grass require large and consecutive precipitation pulses. Co-limitation of photosynthesis of Larrea tridentata by diffusion and biochemistry does not illustrate typical trends across seasons and soil surfaces. Overall results demonstrate the importance of determining the mechanisms responsible for observed leaf-level photosynthetic patterns across individual pulse events, seasons, and contrasting soil surfaces. This is especially important for predicting the magnitude of the response of plant communities in arid and semi-arid ecosystems to species invasions and changes in climate.

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by Iu Chun-ho. / Bibliography: leaves 80-81 / Thesis (M.Ph.)--Chinese University of Hong Kong, 1985

by Cheng Fat-chi. / Bibliography: leaves 85-86 / Thesis (M.Ph.)--Chinese University of Hong Kong, 1984

by Au Wing Shing. / Parallel title in Chinese characters. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 56-58). / Acknowledgements --- p.i / Abstract --- p.ii / Table of Content --- p.iii / Chapter CHATPER 1 : --- INTRODUCTION --- p.1 / Chapter CHAPTER 2 ： --- EXPERIMENTAL SET-UP / Chapter A. --- General Description --- p.4 / Chapter B. --- Vacuum System and Chamber --- p.6 / Chapter C. --- Target Rotation and Motor Connection --- p.7 / Chapter D. --- Substrate Heating and Temperature Control --- p.8 / Chapter E. --- Pressure and Flow Control --- p.9 / Chapter CHAPTER 3 ： --- THICKNESS AND COMPOSITION DISTRIBUTIONS OF FILMS DEPOSITED AT ROOM TEMPERATURE / Chapter A. --- Experimental Details --- p.10 / Chapter B. --- Shape of the Plume --- p.12 / Chapter C. --- Effect of Laser Fluence --- p.15 / Chapter D. --- Investigation of the Pb Deficiency in the Deposited Film --- p.24 / Chapter E. --- Effect of Oxygen Pressure --- p.27 / Chapter CHAPTER 4 ： --- TARGET MODIFICATION AND DEPOSITION RATE / Chapter A. --- Introduction --- p.34 / Chapter B. --- Experimental Details --- p.40 / Chapter C.i. --- Result 1 : Normal Incidence Case --- p.41 / Chapter ii. --- Result 2 : 45° Incidence Case --- p.42 / Chapter D. --- Discussion --- p.43 / Chapter CHAPTER 5 : --- HIGH TEMPERATURE GROWTH ON DIFFERRENT KINDS OF SUBSTRATES / Chapter A. --- Introduction --- p.45 / Chapter B. --- Experimental Details --- p.47 / Chapter C. --- High Temperature Growth / Chapter i. --- Films grown on MgO (100) --- p.49 / Chapter ii. --- Films grown on Spinel --- p.50 / Chapter iii. --- Films grown on c-plane Sapphire --- p.51 / Chapter D. --- Discussion --- p.52 / Chapter CHAPTER 6 ： --- OVERALL CONCLUSION AND FURTHER WORKS --- p.54 / References --- p.56 / Appendix1 --- p.59 / Appendix2 --- p.61

by Poon Kai Lok. / Title also in Chinese. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1990. / Bibliography: leaves 89-90. / LIST OF TABLES --- p.iv / LIST OF FIGURES --- p.v / ACKNOWLEDGEMENTS --- p.vii / ABSTRACT --- p.viii / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter CHAPTER 2 --- LASER PULSE INDUCED DEFORMATION OF DROPLET ： PART I / Chapter 2.1 --- Curvature and surface tension on a deformed surface on the droplet --- p.6 / Chapter 2.2 --- Solution of the Navier-Stokes equation in the absence of viscosity --- p.8 / Chapter CHAPTER 3 --- GEOMETRIC OPTICS ： CALCULATION OF INTERNAL INTENSITY / Chapter 3.1 --- Trace of a narrow light beam inside a droplet --- p.14 / Chapter 3.2 --- Intensity within droplet --- p.16 / Chapter 3.3 --- Mean intensity on the surface of a concentric sphere --- p.25 / Chapter 3.4 --- Intensity on the surface of the droplet --- p.28 / Chapter CHAPTER 4 --- PHYSICAL OPTICS ： MIE SCATTERING / Chapter 4.1 --- "Formalism of Mie Scattering (Mie, 1908〕" --- p.35 / Chapter 4.2 --- Expression of Fl and its result --- p.39 / Chapter CHAPTER 5 --- LASER PULSE INDUCED DEFORMATION OF DROPLET ： PART II / Chapter 5.1 --- Including viscosity --- p.50 / Chapter 5.2 --- Droplet deformation --- p.52 / Chapter 5.3 --- Discussion --- p.58 / Chapter CHAPTER 6 --- TWO FLUID PROBLEM / Chapter 6.1 --- Derivation and discussion of the equation of motion --- p.61 / Chapter 6.2 --- Calculated results --- p.65 / Chapter 6.3 --- The incompressibi1ity assumption --- p.73 / Chapter CHAPTER 7 --- CONCLUSION --- p.76 / APPENDIX A --- p.78 / APPENDIX B --- p.80 / APPENDIX C --- p.82 / APPENDIX D --- p.88 / REFERENCES --- p.89

by Lee Yip-Chi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves [129]-[134]). / Acknowledgments / Abstract / Chapter Chapter 1. --- Introduction --- p.1-1 / Chapter 1.1) --- Recent approaches for wavelength-tunable optical pulse generation --- p.1 -2 / Chapter 1.2) --- Self-seeding a gain-switched Fabry-Perot laser diode --- p.1 -5 / Chapter 1.3) --- About this project --- p.1-8 / Chapter Chapter 2. --- Basic theory --- p.2-1 / Chapter 2.1) --- Basic mechanism of gain-switching --- p.2-1 / Chapter 2.2) --- Mechanism of self-seeding --- p.2-5 / Chapter 2.2.1) --- General principle --- p.2-5 / Chapter 2.2.2) --- Dynamics of singlemode formation --- p.2-7 / Chapter 2.2.3) --- Different cases of modal selection --- p.2-8 / Chapter 2.2.4) --- Reduction of turn-on delay time jitter of optical output --- p.2-10 / Chapter Chapter 3. --- Instrumentation --- p.3-1 / Chapter 3.1) --- Second harmonic autocorrelator --- p.3-1 / Chapter 3.1.1) --- Principle --- p.3-1 / Chapter 3.1.2) --- Description of the 2nd harmonic autocorrelator system --- p.3-3 / Chapter 3.1.3) --- Data acquisition --- p.3-4 / Chapter 3.1.4) --- Alignment and Measurement procedures --- p.3-5 / Chapter 3.1.5) --- Pulsewidth determination by curve fitting --- p.3-7 / Chapter 3.2) --- Optical pulse detection by high speed photodetector --- p.3-9 / Chapter 3.2.1) --- High speed photodetectors --- p.3-9 / Chapter 3.2.2) --- Data acquisition --- p.3-10 / Chapter 3.2.3) --- Deconvolution of the measured optical pulsewidth --- p.3-11 / Chapter Chapter 4 --- Self-seeding 830 nm laser diode using conventional grating method --- p.4-1 / Chapter 4.1) --- Introduction --- p.4-1 / Chapter 4.2) --- Design parameters --- p.4-2 / Chapter 4.2.1) --- External cavity length --- p.4-2 / Chapter 4.2.2) --- Grating orientation --- p.4-3 / Chapter 4.3) --- Experiment --- p.4-4 / Chapter 4.3.1) --- Experimental setup --- p.4-4 / Chapter 4.3.2) --- Equipment Description --- p.4-5 / Chapter 4.4) --- Results and discussion --- p.4-6 / Chapter Chapter 5. --- Self-seeding 1.3 μm LD using fiber-optic configuration --- p.5-1 / Chapter 5.1) --- Optimized operation of self-seeded laser diode --- p.5-1 / Chapter 5.1.1) --- General Description --- p.5-1 / Chapter 5.1.2) --- Components --- p.5-1 / Chapter 5.1.3) --- Experimental setup --- p.5-6 / Chapter 5.1.4) --- Feedback rate measurement --- p.5-8 / Chapter 5.1.5) --- Results and discussion --- p.5-9 / Chapter 5.2) --- Electrical bias dependence on the self-seeded LD --- p.5-15 / Chapter 5.3) --- An efficient scheme to improve tuning range and provide continuous tuning --- p.5-20 / Chapter 5.3.1) --- General Description --- p.5-20 / Chapter 5.3.2) --- Principle of thermal control scheme --- p.5-20 / Chapter 5.3.3) --- Experimental setup --- p.5-22 / Chapter 5.3.4) --- Results and Discussions --- p.5-23 / Chapter Chapter 6. --- A novel self-seeding configuration --- p.6-1 / Chapter 6.1) --- Principle --- p.6-1 / Chapter 6.2) --- Highly dispersion-shifted fiber --- p.6-2 / Chapter 6.3) --- Optical fiber-mirror --- p.6-3 / Chapter 6.3.1 --- Fabrication --- p.6-4 / Chapter 6.3.2) --- Characterization: --- p.6-6 / Chapter 6.4) --- Experiment --- p.6-10 / Chapter 6.5) --- Results --- p.6-12 / Chapter 6.6) --- Discussions --- p.6-27 / Chapter 6.6.1) --- Electrical tuning characteristic --- p.6-27 / Chapter 6.6.2) --- Sidemode supression ratio characteristics --- p.6-30 / Chapter 6.6.3) --- Thermal tuning characteristics --- p.6-33 / Chapter 6.7) --- Summary --- p.6-36 / Chapter Chapter 7. --- Half-period delayed dual-wavelength picosecond optical pulse generation using a self-seeded laser diode --- p.7-1 / Chapter 7.1) --- Introduction --- p.7-1 / Chapter 7.2) --- Principle --- p.7-2 / Chapter 7.3) --- Experiment --- p.7-4 / Chapter 7.4) --- Results and discussions --- p.7-5 / Chapter Chapter 8. --- A proposed self-seeding configuration for the programmable multi- wavelength optical pulse generation --- p.8-1 / Chapter Chapter 9. --- Conclusion --- p.9-1 / References / Appendix / List of accepted and submitted publications

Thesis (Ph.D.)--McMaster University, 2004. / Supervisor: Dr. H.K. Haugen and Dr. P. Mascher. Includes bibliographical references (p. 135-143). Also available via World Wide Web.

Interference has long been used for precision measurement of path-length changes. Since the advent of the laser, interference has become one of the most versatile tools in metrology. Specifically, ultra-short laser pulses allow unprecedented resolution in absolute length measurements. While ultra-short laser pulses lead to high resolution, for example in white-light interferometry, they are very susceptible to dispersion. Quantum resources have been proposed to overcome some of the problems related to distortions in the interferometric signal. For example, the Hong-Ou-Mandel (HOM) interferometer relies on frequency-entangled photon pairs and features automatic even-order dispersion cancellation and high interference visibility resilient to unbalanced loss. Quantum-OCT is a technique based on HOM interferometry, that promises to overcome Optical Coherence Tomography (OCT) a classical imaging technique based on low coherence light. Furthermore, straightforward modifications of the HOM interferometer can display several different interferometric signals, including the HOM peak, quantum beating, and phase super-resolution. However, the quantum resources required are hard to produce and dim, leading to long integration times and single-photon counting. In this thesis, we introduce the theory behind Chirped-Pulse Interferometry (CPI), a new technique that combines all the advantages of Q-OCT, including even-order dispersion cancellation, but without the need for any quantum resources. We then experimentally implement CPI and demonstrate all the important characteristics shared by the HOM interferometer, but at dramatically larger signal levels. We show how CPI can be used to measure dispersion cancelled axial profiles of an optical sample and show the improvement in resolution over white-light interferometry. Finally, we show that by modifying CPI in analogous ways to HOM, CPI can also be made to produce interferometric signal identical to the HOM peak, quantum beating, and phase super-resolution.