Amplification of surface plasmon polaritons in plasmonic systems have been of great interest for realizing active nanophotonic devices. In this thesis, we present a study about optical gain of SPPs supported in planar metallo-organic multilayer structures based on the Kretchmann geometry. First, we present the effect of varying the geometry on behaviours of surface plasmon propagation, which appear as the change of angular reflectivity. A theoretical approach explains the characteristics well. A kind of conjugated polymer material is introduced to the structures for obtaining gain. A film of this material with nanometer thickness is attached close to a metallic layer, being optically excited to supply energy. For understanding the interaction between surface plasmon polaritons and the active films, we experimentally investigate energy transfer channels from the active material to surface plasmons with an aid of a theoretical analysis. This result provides a strong evidence of being capable of exciting surface plasmon polaritons via dipole excitation. We also report an experimental demonstration of optical gain properties in conventional waveguide structures where the active material acts as propagating channel by measuring amplified spontaneous emission phenomena, providing information of achievable optical gain. Based on the strong evidences of both the active and passive properties, we demonstrate plasmonic gain in the structure incorporating the polymer film for the first time. For this, a double lock-in amplifier system is introduced. Plasmonic modal gain is explained with a support of theoretical estimates. The achieved modal gain is 9 cm-1. This work suggests the design principle for active nano plasmonic devices.

This dissertation documents my mathematical and computational models of the charging of spherical dust grains in plasmas. The mathematical models are stochastic models which predict the equilibrium probability distribution of a sphere's charge state q in a collisionless, flowing plasma with Debye length λ_D. I solve the models for the distribution's exact form and deduce closed-form Gaussian approximations to it. The approximations' mean and variance are of order Ω at large Ω, where the dimensionless quantity Ω equals 3 N_D a / λ_D, N_D being the plasma's Debye number and a the sphere's radius. Faster plasma flow increases q's variance for spheres much smaller than λ_D, but does not affect the variance for large (a >> λ_D) spheres. My computational model is pot, a simulator of a sphere in a flowing, homogeneously magnetized plasma, and the first to be fully microscopic with non-interpolated fields. I describe pot's design, present test results confirming that pot produces sensible output, and detail pot-derived estimates of a sphere's normalized, equilibrium surface potential η_a as a function of the dimensionless magnetization β_i and plasma flow speed. pot's η_a values come within 5% of those predicted by the existing "SOML" theory of spheres in flowing plasmas, and q's equilibrium fluctuations during pot simulations statistically match those predicted by my stochastic modelling. Another comparison, of pot's results against past simulations - only partially microscopic - and against an unmagnetized-ion theory, verifies the earlier simulations' implication that the unmagnetized-ion theory is incorrect when β_i is small but non-negligible. Contra the theory, gently magnetizing a proton-electron plasma by increasing its β_i from zero to 0.4 does not raise η_a by 0.4, but at most by 0.1.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

In this thesis, we have described an extension to R-Matrix with Time Dependence (RMT) theory and associated codes that allows full modelling of ultrafast double ionisation processes. This approach extends the capability of R-Matrix methods to model ionisation and scattering processes in many electron problems. Previously, all R-Matrix methods for double ionisation were either time-independent (e.g IERM) (and hence incapable of modelling the ultrafast processes of contemporary interest), or incapable of representing configuration space to the extent necessary to model double ionisation wavepackets (e.g. traditional RMT). This thesis demonstrates the feasibility of application of the RMT formalism to the study of double ionisation processes through application to for two and three electron systems.

A series of N-methyl-N’,N’-dimethylethylene-/-propylene-diaminodithiocarbamato-metal complexes [M(S2CN(Me)(CH2)nN(Me)2)2] (M = Zn, Cd, Cu, Ni; n = 2 or 3), [M(S2CN(Me)(CH2)nN(Me)2)3] (M = Co, In; n = 2 or 3), [M(S2CN(Me)(CH2)nN(Me)2)] (M = Ag; n = 3) has been synthesized and characterised by microelemental analysis, NMR (1H, 13C), IR and some by X-ray crystallography. X-ray single crystal structures for [M(S2CN(Me)(CH2)nN(Me)2)2] (M = Zn, Cd, n = 2 or 3) and [M(S2CN(Me)(CH2)nN(Me)2)3] (M = In; n = 2 or 3) have been determined. Zinc and cadmium structures are polymers. All polymerise through the nitrogen of dimethylamino group to the metal atoms. Both indium structures are monomers where each indium is bonded with six sulphur atoms from three bidentate dithiocarbamato ligands.All twelve metal complexes were solids and stable to air and moisture for periods of several months hence potentially useful as single source precursor for metal sulfide thin films. Metal sulfide thin films including zinc sulfide, cadmium sulfide, copper sulfide, nickel sulfide, cobalt sulfide, indium sulfide, copper indium sulfide, silver indium sulfide, and cadmium zinc sulfide were deposited by aerosol assisted chemical vapour deposition (AACVD) method. Deposition from each precursor was carried out at three different (300, 400 and 500 °C) temperatures to investigate the effect of deposition temperature on the size and shape of crystallites as well as phase of the material. All deposited films were characterized by powder X-ray diffraction (p-XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and atomic force microscopy (AFM). Mostly good quality, adhesive and specular thin films of these materials were obtained. p-XRD showed significant changes in the phase of materials depending upon the growth temperature. SEM and AFM images showed the morphology of the films was strongly linked to the deposition temperature. This is the first systematic study on N-methyl-N’,N’-dimethylethylene-/-propylene-diaminodithiocarbamatometal complexes and their use as single source precursors for the metal sulfide thin films.