ANGLE-RESOLVED OPTICAL SPECTROSCOPY OF PLASMONIC RESONANCES

Controllable manipulation of light propagation on nanostructured plasmonic materials paves the way to the observation of a wealth of optical and quantum phenomena. The development of versatile plasmonic resonance detection techniques accelerated the pace of plasmonic studies. In this dissertation, momentum plane mapping of plasmonic modes from periodic structures is discussed. Chapter 1 presents a theoretical introduction to the distinct types of localized and nonlocalized resonances being studied throughout this work. A historical overview of plasmonic resonance engineering and applications development is also provided with a standard classification of plasmonic resonances according to their propagation behavior. Chapter 2 provides the theoretical introduction to back-focal plane imaging technique and the technical description for the Fourier-space spectroscope and microscope that is mainly used for momentum plane scanning to generate angular reflection maps. The measurements’ capabilities of the spectroscope are discussed. This construction helped in obtaining the dispersion maps from the micro-sized arrays of symmetric planar and vertically stacked nanoparticles in chapter 3 and the asymmetric nanorod and nanodimer lattices in chapter 4. Chapter 3 discusses the generated plasmonic resonances on gold nanoparticle arrays in singular planar form, discrete vertical metal-insulator-metal (MIM) stacks, along with the hybrid nanoparticle-film MIM arrays. Reflection dispersion maps measured by Fourier space spectroscopy shows the formation of single dipolar localized modes, a fundamental MIM mode, and a dispersive diffractive order resonance. The gap mode at the hybrid structure showed the highest electric field confinement amongst the resonances supported by the studied set of geometries. In chapter 4 the plasmonic resonances on periodic nanorod and nanorod-dimers are studied. Nanorod and nanodimer arrays exhibit rich optical responses due to their unique polarization and orientation spectral. Chapter 5 is dedicated to the generation of surface plasmon polaritons (SPPs) on silver-based metal-insulator-metal (MIM) cross mesh gratings. Specular and monochromatic studies were performed to investigate the linear optical properties of the MIM stack. MIM micro-mesh gratings were found to support highly dispersive SPP modes of a respective 2D square array. Increasing the pitch and the slab width increases the number of generated SPP modes. The main modes as the periodicity increases exhibit steep dispersions over a long range of frequencies, and thus high group velocities which is promising for waveguide applications since their nano-counterparts lack the large dispersion wavelength span. Chapter 6 describes the fabrication procedures pursued at Michigan Technological University fabrication facilities to produce metallic nanocavities of either single planar or vertical MIM stacking supporting LSP mode formation at visible and near infrared frequencies for quantum emitter-LSP resonant coupling studies