Experimental and theoretical studies of the optical properties of periodic metallic nanostructures

Surface plasmons (SP), the collective oscillations of the conduction electrons between the metal/dielectric interface, strongly influence the optical properties of metallic nanostructures and are of great interest for future photonic devices. Here, this thesis mainly focuses on the experimental and theoretical investigations on the optical properties of the metallic periodic nanostructures.;Firstly, studies are performed on finding an in-depth understanding into the optical properties of two-dimensional (2D) metallic nano-cavity structure (grating). Structures are fabricated by interference lithography and thin film techniques. Grating geometries can be easily tuned by using these versatile techniques with high reproducibility and precision. Plasmonic dispersion in the 2D grating has been mapped out by angle-dependent reflectivity measurements. Two particular nanostructures, i.e., nano-bottle array and elliptical hole array, have been chosen to investigate the dependence of plasmonic properties on geometries change. Theories are also put forward to understand the origin and electromagnetic properties of the obtained plasmonic modes.;With an understanding into the different plasmonic properties of the metallic nanostructures, researches are then undertaken to explore how this associated electromagnetic field interacts with the molecules adsorbed onto a sample surface. The distinct and strong correlation between the plasmonic modes and surface enhanced Raman scattering (SERS) is verified on the one-dimensional silver grating. In particular, the detailed analysis of the enhancement factor from surface plasmons excitation and de-excitation process in SERS has been performed. On the other hand, the technique used to fabricate the controllable "hot spot" for enhancing Raman scattering has been introduced on the 2D metallic grating. Complemented by the theoretical simulation, the conditions for optimizing SERS enhancement effect are proposed.;Finally, this thesis presents an approach to quantitatively evaluate the SP-mediated light emission. Based on this consideration, efforts are taken to find the temperature effect of SP on the light emission in semiconductor. On metal/ZnO system, a more realistic picture for the light emission is depicted by experimentally measuring the temperature-dependent photoluminescence and theoretically calculating the Purcell enhancement factor. The increasing plasmonic density of states with the lower temperature has been regarded as being responsible for the enhanced light emission.;By combining experiment and theory, we believe our study shed light on developing a new method for well investigating and controlling the different plasmonic modes and open their way for some great applications in biology, chemistry and photonics.