Thesis (BSc. (Hons))--Australian National University, 2002. / Available via the Australian National University Library Electronic Pre and Post Print Repository. Title from title screen (viewed Mar. 27, 2003). "November, 2002" "A thesis submitted in part fulfillment of the requirements for the degree of Bachelor of Science with Honours, from the Department of Physics, The Australian National University" Includes bibliographical references.

Thesis (Ph. D.)--Worcester Polytechnic Institute. / Keywords: vortex; coherence. Includes bibliographical references (p. 127-151).

Thesis (Ph. D.)--Worcester Polytechnic Institute. / Keywords: singularity; vortex; phase; diffraction; interference; nulling; singularities; coherence; dislocation; optical vortex. Includes bibliographical references (p. 123-146).

Thesis (Ph. D.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.

No description available.

published_or_final_version / abstract / Anatomy / Doctoral / Doctor of Philosophy

"Optical vortices are singularities in phase fronts of optical beams. They are characterized by a dark core in the center and by a helical wave front. Owing to azimuthal components of wave vectors, an optical vortex carries orbital angular momentum. Previously, optical vortices were studied only in coherent beams with a well-defined phase. The object of this dissertation is to explore vortices in partially coherent systems where statistics are required to quantify the phase. We consider parametric scattering of a vortex beam and a vortex placed on partially coherent beam. Optical coherence theory provides the mathematical apparatus in the form of the mutual coherence function describing the correlation properties of two points in a beam. Experimentally, the wave-front folding interferometer allows analysis of the cross-correlation function, which may be used to study partial coherence effects even when traditional interferometric techniques fail. We developed the theory of composite optical vortices, which can occur when two coherent beams are superimposed. We then reported the first experimental observation of vortices in a cross-correlation function (which we call spatial correlation vortices). We found numerically and experimentally how the varying transverse coherence length and position of a vortex in a beam may affect the position and existence of spatial correlation vortices. The results presented in this thesis offer a better understanding of the concept of phase in partially coherent light. The spatial correlation vortex presents a new tool to manipulate coherence properties of an optical beam."

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

No description available.

Semiconductor quantum dots tightly confine excited electron-hole pairs, called excitons, resulting in discrete energy levels similar to those of single atoms. Transition energies in the visible or near-infrared make quantum dots suitable for many applications in quantum optics and quantum information science, but to take advantage of all the properties of quantum dot emission, it is necessary to excite them coherently which has been a great challenge due to background scattering of the excitation laser. This dissertation presents the first coherent control of a single quantum dot with observation of its resonance fluorescence and decoherence phenomena. Strong continuous-wave excitation causes the dot to undergo several Rabi oscillations before emitting. These are visible as oscillations in the first- and second-order correlation functions of the emission, and the quantum dot states are "dressed", resulting in a Mollow triplet in the emission spectrum. Some resonantly excited dots, in addition to resonance fluorescence, also emit light from excited states several meV higher in energy. Such up-conversion fits existing theories of decoherence but has never been directly observed before. The up-conversion intensity is shown to be described well by a fairly simple three-level model with single-phonon absorption. The coherent phenomena of resonance fluorescence and the decoherence due to up-conversion paint a dual picture of single quantum dots wherein they can sometimes be treated as an ideal two-level system, but their interactions with the host crystal can lead to many complex behaviors. / text