A practical geometric optics method for derivation of the optical forces from light rays was described. By this method, the forces from a G.P.W. (Gaussian Plane Wave) and a general TEM$ sb infty$ laser beam were calculated and studied. For a G.P.W. beam, there were two forces which acted on small particles located inside the electromagnetic field; one, called the scattering force, directed in the beam propagation direction, pushed particles axially. The other, called the gradient force, due to the non-uniformity of the electromagnetic field, acted like an optical well and confined the particles of the beam axis. The forces from a general TEM$ sb infty$ beam behaved differently due to the profile of the beam. It was shown that axial confinement was also possible for a highly focused TEM$ sb infty$ beam, therefore providing the possibility of single beam trapping. The relationship between the forces and the profile of a TEM$ sb infty$ laser beam was investigated comprehensively. / Three experimental stations were designed and built. Both upward and downward accelerating experiments were constructed to confirm the existences of the scattering force and the gradient force in a G.P.W. beam. Furthermore, the scattering force was studied quantitatively. A single beam trapping experiment was designed to verify the possibility of axial constraint of small particles by a higher focused TEM$ sb infty$ laser beam. The single beam trapping conditions found in the experiment were in agreement with the results of the theoretical analysis.

An emission spectroscopy study was performed on a magnetically rotated electric arc between two concentric copper electrodes. Two methods were proposed to analyse the recordings of the line intensities as the arc column passed in front of the optical system. / The averaging of a series of intensity profiles was the first method. Consistancy between the average value of some parameters applied to these profiles and the value of these parameters on the average quantity was checked. Volumetric emissivity profiles were then obtained. / The second method consisted of electronic integration of line intensities during several arc passings. The proportionality between this average intensity and the maximum emissivity in the arc column was checked. / These two methods were used to determine the copper vapour density and the arc temperature as a function of two contaminants in the main argon flux: carbon monoxyde and nitrogen. The temperature was slightly superior to 7500 K in the first case and slightly inferior in the second. Maximum copper vapour density found was 5 10$ sp{21}$ m$ sp{-3}$ in argon contaminated with carbon monoxide. It was probably higher than 10$ sp{22}$ m$ sp{-3}$ in Argon contaminated with nitrogen.

Bifurcations and complex oscillations in the human pupil light reflex (PLR) are studied. Autonomous pupil area oscillations are produced by substituting electronically controllable nonlinear feedback for the normal negative feedback of this reflex. A physiologically sound theoretical framework in which to study pupillary oscillations is developed. The model, framed as a delay-differential equation (DDE), agrees quantitatively with the simpler periodic behaviors and qualitatively with the complex behaviors. Much of the aperiodicity in the data can be ascribed to noise and transients rather than to chaos. The critical behavior of the PLR at oscillation onset is different with piecewise constant rather than smooth negative feedback. In the former, relative fluctuations in period are larger than those in amplitude, and vice versa in the latter. Properties of the time solutions and densities of a stochastic DDE are used to explain this experimental result. The Hopf bifurcation in this system is postponed by both additive and multiplicative colored noise. Theoretical insight into the behavior of stationary densities of DDE's and the origin of the postponement is given, and implications for analyzing bifurcations in neural delayed feedback systems are discussed.

Ultra-small angle light scattering (USALS) is a technique used to probe large average spatial and temporal structure of soft condensed matter complementary to microscopy. Limited information is available on the design and features of a multi-speckle CCD-based USALS apparatus. The optics of such a setup are described followed by an optimization scheme involving ray tracing that can be used to choose the optimum lenses by taking into account the finite spot size due to lens aberrations, diffraction, and the CCD pixel size. Results of calculations of the optimization scheme are presented for a static light scattering (SLS) setup followed by a few experimental tests of our current apparatus.

No description available.

Quantum optics provides powerful means to probe quantum mechanics. In this thesis, we study various aspects of quantum phenomena arising in quantum optical systems. Part I studies broadband quantum teleportation. After presenting three different methods of analyzing the standard teleportation protocol, we study the interplay between various bandwidths in determining the fidelity of a broadband quantum field teleportation. Explicit formulae for the degrees of first- and secondorder coherence for the teleportation of resonance fluorescence are derived for this purpose. Part II studies entanglement arising in cascaded open quantum (optical) systems. First, a detailed laser model is produced within quantum trajectory theory to study the total decoherence rate of a laser-driven qubit. Second, using this model, we address the issue of laser quantum state, viewed in connection with separability of the laser-driven-qubit system. Third, a measure of entanglement within quantum trajectory theory called ‘Contextual Entanglement’ is calculated for a few simple systems and compared with the ‘Entanglement of Formation’. Lastly, we introduce a method to quantify entanglement (based on the contextual entanglement) between a source and the field it emits, which we call the ‘Entanglement Spectrum’. It is applied to study the entanglement between a laser-driven qubit and the field the qubit scatters.

Quantum optics provides powerful means to probe quantum mechanics. In this thesis, we study various aspects of quantum phenomena arising in quantum optical systems. Part I studies broadband quantum teleportation. After presenting three different methods of analyzing the standard teleportation protocol, we study the interplay between various bandwidths in determining the fidelity of a broadband quantum field teleportation. Explicit formulae for the degrees of first- and secondorder coherence for the teleportation of resonance fluorescence are derived for this purpose. Part II studies entanglement arising in cascaded open quantum (optical) systems. First, a detailed laser model is produced within quantum trajectory theory to study the total decoherence rate of a laser-driven qubit. Second, using this model, we address the issue of laser quantum state, viewed in connection with separability of the laser-driven-qubit system. Third, a measure of entanglement within quantum trajectory theory called ‘Contextual Entanglement’ is calculated for a few simple systems and compared with the ‘Entanglement of Formation’. Lastly, we introduce a method to quantify entanglement (based on the contextual entanglement) between a source and the field it emits, which we call the ‘Entanglement Spectrum’. It is applied to study the entanglement between a laser-driven qubit and the field the qubit scatters.

Quantum optics provides powerful means to probe quantum mechanics. In this thesis, we study various aspects of quantum phenomena arising in quantum optical systems. Part I studies broadband quantum teleportation. After presenting three different methods of analyzing the standard teleportation protocol, we study the interplay between various bandwidths in determining the fidelity of a broadband quantum field teleportation. Explicit formulae for the degrees of first- and secondorder coherence for the teleportation of resonance fluorescence are derived for this purpose. Part II studies entanglement arising in cascaded open quantum (optical) systems. First, a detailed laser model is produced within quantum trajectory theory to study the total decoherence rate of a laser-driven qubit. Second, using this model, we address the issue of laser quantum state, viewed in connection with separability of the laser-driven-qubit system. Third, a measure of entanglement within quantum trajectory theory called ‘Contextual Entanglement’ is calculated for a few simple systems and compared with the ‘Entanglement of Formation’. Lastly, we introduce a method to quantify entanglement (based on the contextual entanglement) between a source and the field it emits, which we call the ‘Entanglement Spectrum’. It is applied to study the entanglement between a laser-driven qubit and the field the qubit scatters.

Thesis (M.Sc.)--York University, 2006. Graduate Programme in Physics. / Typescript. Includes bibliographical references (leaves 110-115). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR29614

Thesis (Ph. D.)--Lehigh University, 2005. / Includes vita. Adviser: H. Daniel Ou-Yang. Bibliography: leaves 151-157.