Plasmonics can be applied in a wide range of optoelectronic devices and it is induced by the interaction between incident light and conduction electrons. Resonance is induced by matching the photon energy and the frequency of electrons, which can cause the surface charge distribution and strengthens the electromagnetic field. Generally, plasmonics can be classified into surface plasmon resonance (SPR) and localized surface plasmon resonance (LSPR). SPR is the propagating wave, which occurs at interface between the dielectric and metal. LSPR is the non-propagating wave, which is the interaction between the metal nanoparticles (NPs) and incident light when the NP size is smaller than the light wavelength. In this thesis, plasmonic enhancement is studied to improve the performance of organic solar cells (OSCs) and light emission of organic semiconductors. OSCs are low cost, light weight, flexibility, and solution process ability at room temperature. Short exciton diffusion length limits the thickness of active layer, which causes low photon absorption and consequently low current generation. In this part, gold nanoparticles (Au NPs) are blended into OSCs to enhance photovoltaic performance. Au NPs can induce the localized surface plasmon resonance (LSPR) which enhances the light absorption due to electromagnetic field generation. Also, light can be trapped by scattering to increase the optical path and thus enhance the charge carrier generation. Film structure and 1D nanostructure of organic semiconductor are studied by their photoluminescence (PL) intensity. Generally, the PL intensity can be enhanced by SPR. Excitation energy can induce the surface plasmon (SP) instead of photon, which can amplify the spontaneous emission and stimulated emission. Compared to thin films, 1D organic structures achieve higher PL enhancement because they can trap the light more efficiently by Fabry-Pérot cavity. Different morphologies of organic semiconductor are synthesized and it is found that hexagonal plates can obtain better PL enhancement because of the Fabry-Pérot cavity mode. / published_or_final_version / Physics / Master / Master of Philosophy

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

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (p. 133-139).

Thesis (Ph. D.)--University of Chicago, Dept. of Chemistry, August 2001. / Includes bibliographical references. Also available on the Internet.

Metallic films with narrow and deep subwavelength gratings or holes having a converging-diverging channel (CDC) can exhibit enhanced transmission resonances for wavelengths larger than the periodicity of the grating or hole. Using the finite element method, it is shown that by varying the gap size at the throat of a CDC, the spectral locations of the transmission resonance bands can be shifted close to each other and have high transmittance in a very narrow energy band. Additionally, the transmission of light can be influenced by the presence of the externally applied magnetic field H. The spectral locations of the transmission peak resonances depend on the magnitude and the direction of H. The transmission peaks have blue-shift with the increase in H. A new multilayer thermal emitter has been analyzed in the visible wavelength range. The proposed emitter has large temporal and spatial coherence extending into the far field. The thermal emitter is made up of a cavity that is surrounded by a thin silver grating having a CDC on one side and a one-dimensional (1D) photonic crystal (PhC) on the other side. The large coherence length is achieved by making use of the coherence properties of the surface waves. Due to the nature of surface waves the new multilayer structure can attain the spectral and directional control of emission with only ppolarization. The resonance condition inside the cavity is extremely sensitive to the wavelength, which would then lead to high emission in a very narrow wavelength band. In addition a new tunable plasmonic crystal (tPLC) was proposed, where the plasmonic or polaritonic mode of a metallic array can be combined with the photonic mode of a hole array in a dielectric slab for achieving negative refraction and still posses an extra degree of freedom for tuning the tPLC as a superlens to operate at different frequencies. The tunability of the single planar tPLC slab is demonstrated numerically for subwavelength imaging (FWHM 0.38[lambda]~ 0.42[lambda]) by just varying the fluid in the hole array, thereby enabling the realization of ultracompact tunable superlens and paving the way for a new class of lens. An aggressive pursuit for decreasing the minimum feature size in high bandgap materials has lead to various challenges in nanofabrication. However, it is difficult to achieve critical dimensions at sub-wavelength scale using traditional optical lithography. A new technique to create submicron patterns on hard-to-machine materials like silicon carbide (SiC) and borosilicate glass with a laser beam is demonstrated. Here the principle of optical near-field enhancement between the spheres and substrate when irradiated by a laser beam has been used for obtaining the patterning.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (M. Sc.)--University of Alberta, 2009. / Title from pdf file main screen (viewed on Sept 22, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Electrical and Computer Engineering, University of Alberta." Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (leaves [137]-142).

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 152-162).

Plasmonic devices, consisting of subwavelength nanostructures at optical frequency, have been widely applied to many research .elds such as bio-sensing, super-resolution imaging, energy harvesting, nanolaser and so on. The strong con.ned electromag­netic .elds in the a.nity of nanostructures provides an e.cient channel to guide, enhance, and modulate light energy beyond the di.raction limit. In this thesis, we .rst studied the plasmonic devices in linear optical regime, especially from the view of phase information in the light matter interaction; then more e.orts were paid to the nonlinear plasmonics, in which the organic-plasmonic hybrid nanostructures provided a useful platform for demonstrating some interesting physical phenomena. Firstly, we studied the fundamental optical properties of typically propagating surface plasmonic polariton (SPPs), which were generated by plasmonic gratings. Optical elliptical response of excited SPPs was studied experimentally and theoret­ically in both amplitude and phase domains. Then we studied the strong coupling e.ect from plasmonic Fabry-Perot nanocavity, in which giant Rabi splitting phe­nomenon with a splitting energy ~ 148 meV was obtained experimentally. From these studies, the interaction of SPP wave with other resonant structures were well understood from the view point of phase evolution. Secondly, we moved from linear optics the nonlinear plasmonic optics and tried to understand how the plasmon enhancement acts on the nonlinear optical processes. In the .rst example, plasmon enhanced third harmonic generation (THG) on one dimensional gratings was experimentally demonstrated by integrating the nonlinear active medium into the plasmonic devices. Later, the generation of THG vortex beam was also realized by introducing hologram based plasmonic design. Lastly, we re-examined a conventional symmetry problem in nonlinear molecular optics. It was found the that the metacrystal, consisting of plasmonic molecule with feature size much larger than conventional molecules, also follows the conventional selection rules of third harmonic generation. We believe the knowledge we accumulated in this work also provides a strong background for our future studies on ultra-fast plasmonic switching, in which the all-optical low loss, optical switch can be realized by using the engineered optical properties of plasmonic devices.