Ling, Chi Wai = 在等離子體鏈中使光變慢 / 凌志偉. / "September 2010." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (p. 73-76). / Abstracts in English and Chinese. / Ling, Chi Wai = Zai deng li zi ti lian zhong shi guang bian man / Ling Zhiwei. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Slowing down of light --- p.1 / Chapter 1.2 --- Objectives of the thesis --- p.4 / Chapter 2 --- Review on Bergman-Milton Theory of Green Function --- p.5 / Chapter 2.1 --- Green function for Laplace operator --- p.5 / Chapter 2.2 --- Integral equation for two-component systems --- p.6 / Chapter 2.3 --- Symbolic solution for two-component systems --- p.10 / Chapter 2.4 --- An isolated dielectric sphere --- p.11 / Chapter 2.5 --- Extension to a collection of multi-interacting spheres --- p.13 / Chapter 3 --- Slowing Light by Multipolar Effect in Metal Nanoparticle Chains --- p.16 / Chapter 3.1 --- Evaluating the dispersion relations --- p.17 / Chapter 3.2 --- Results and discussions on multipolar effects --- p.20 / Chapter 4 --- Level Repulsion Phenomenon --- p.23 / Chapter 4.1 --- Two coupled oscillators --- p.24 / Chapter 4.1.1 --- Normal mode method --- p.24 / Chapter 4.1.2 --- Forccd oscillator method --- p.25 / Chapter 4.2 --- Metallic nanoshells --- p.25 / Chapter 4.3 --- Two coupled metal nanoparticles --- p.27 / Chapter 4.4 --- Diatomic spring-mass chain --- p.28 / Chapter 4.4.1 --- Dispersion relation --- p.29 / Chapter 4.4.2 --- Forced oscillator method --- p.30 / Chapter 5 --- Slowing Light by Hybridization of Bands in Plasmonic Chains --- p.34 / Chapter 5.1 --- Coupled dipole equation of plasmonic Chains --- p.34 / Chapter 5.2 --- Monatomic metal nanoparticle chains --- p.36 / Chapter 5.3 --- Diatomic chains formed by unshcllcd metal nanoparticles and shelled metal nanoparticles --- p.39 / Chapter 5.3.1 --- Formalism for evaluating dispersion relation --- p.39 / Chapter 5.3.2 --- Hybridization of bands --- p.42 / Chapter 5.3.3 --- Stopping light using photon-phonon assisted proccss --- p.45 / Chapter 5.3.4 --- Discussions --- p.47 / Chapter 5.4 --- Monatomic chains formed by nanoshells --- p.49 / Chapter 5.4.1 --- Formalism --- p.50 / Chapter 5.4.2 --- Numerical results and discussions --- p.54 / Chapter 5.4.3 --- Conclusions --- p.57 / Chapter 5.5 --- Diatomic chains formed by two types of dielectric shelled nano- particles --- p.60 / Chapter 5.5.1 --- Formalism for evaluating dispersion relation --- p.60 / Chapter 5.5.2 --- Results and discussions --- p.63 / Chapter 5.6 --- Yin-yang plasmonic chain --- p.68 / Chapter 6 --- Summary --- p.71 / Bibliography --- p.73 / Chapter A --- Properties of operator Γ --- p.77 / Chapter A.1 --- Hermitian Property of operator Γ --- p.77 / Chapter A.2 --- Eigenfunctions and eigenvalues of operator Γ for isolated spheres --- p.78 / Chapter B --- Drude Model and Polarizabilities of Spheres --- p.82 / Chapter B.1 --- Drude Model --- p.82 / Chapter B.2 --- Polarizabilities of spheres --- p.83 / Chapter C --- Dyadic Green's Function --- p.85

Thèse : Sciences physiques : Paris, Faculté des sciences : 1853. / Titre provenant de l'écran-titre.

No description available.

The object of this research was to develop a technique that could measure the velocity of light indirectly, with some degree of accuracy; yet could be used to demonstrate the physical fact of this velocity of light to groups of students or interested observers.

by Ng Chiu-king. / Chinese title: / Bibliography: leaves 68-69 / Thesis (M.Phil.)--Chinese University of Hong Kong, 1983

In the past decade, great research effort was inspired by the need to realise active optical functionalities in silicon, in order to develop the full potential of silicon as a photonic platform. In this thesis we explore the possibility of achieving tunable delay and optical gain in silicon, taking advantage of the unique dispersion capabilities of photonic crystals. To achieve tunable optical delay, we adopt a wavelength conversion and group velocity dispersion approach in a miniaturised engineered slow light photonic crystal waveguide. Our scheme is equivalent to a two-step indirect photonic transition, involving an alteration of both the frequency and momentum of an optical pulse, where the former is modified by the adiabatic tuning possibilities enabled by slow light. We apply this concept in a demonstration of continuous tunability of the delay of pulses, and exploit the ultrafast nature of the tuning process to demonstrate manipulation of a single pulse in a train of two pulses. In order to address the propagation loss intrinsic to slow light structures, with a prospect for improving the performance of the tunable delay device, we also investigate the nonlinear effect of stimulated Raman scattering as a means of introducing optical gain in silicon. We study the influence of slowdown factors and pump-induced losses on the evolution of a signal beam along the waveguide, as well as the role of linear propagation loss and mode profile changes typical of realistic photonic crystal structures. We then describe the work conducted for the experimental demonstration of such effect and its enhancement due to slow light. Finally, as the Raman nonlinearity may become useful also in photonic crystal nanocavities, which confine light in very small volumes, we discuss the design and realisation of structures which satisfy the basic requirements on the resonant modes needed for improving Raman scattering.

The field of nanophotonics is a major research topic, as it offers potential solutions to important challenges, such as the creation of low power, high bandwidth interconnects or optical sensors. Within this field, resonant structures and slow light waveguides are used to improve device performance further. Photonic crystals are of particular interest, as they allow the fabrication of a wide variety of structures, including high Q-factor cavities and slow light waveguides. The high scattering loss of photonic crystal waveguides, caused by fabrication disorder, however, has so far proven to be the limiting factor for device applications. In this thesis, I present a detailed study of propagation loss in slow light photonic crystal waveguides. I examine the dependence of propagation loss on the group index, and on disorder, in more depth than previous work by other authors. I present a detailed study of the relative importance of different components of the propagation loss, as well as a calculation method for the average device properties. A new calculation method is introduced to study different device designs and to show that photonic crystal waveguide propagation loss can be reduced by device design alone. These “loss engineered” waveguides have been used to demonstrate the lowest loss photonic crystal based delay line (35 dB/ns) with further improvements being predicted (< 20 dB/ns). Novel fabrication techniques were investigated, with the aim of reducing fabrication disorder. Initial results showed the feasibility of a silicon anneal in a nitrogen atmosphere, however poor process control led to repeatability issues. The use of a slow-fast-slow light interface allowed for the fabrication of waveguides spanning multiple writefields of the electron-beam lithography tool, overcoming the problem of stitching errors. The slow-fast-slow light interfaces were combined with loss engineering waveguide designs, to achieve an order of magnitude reduction in the propagation loss compared to a W1 waveguide, with values as low as 130 dB/cm being achieved for a group index around 60.