| This thesis describes the application of single molecule detection and spectroscopy techniques to investigate the electronic and vibrational properties of individual bundles of aligned single wall carbon nanotubes (SWNTs). Due to their unique properties, SWNTs may find wide applications in nanoscale science and technology.; Rayleigh scattering spectra of single SWNT bundles are measured using dark field optical microscopy. Resonance peaks due to the optically allowed interband transitions in SWNTs are revealed in the Rayleigh scattering spectra. Polarization dependent measurements show that the interband transition dipoles are orientated parallel to the tube axis.; Resonance enhanced Raman spectra from single SWNT bundles are successfully measured using Raman microscopy. A new method, backscattering confocal Raman microscopy with a copper grid as the substrate, is developed to measure high signal-to-noise ratio Raman spectra, in which the broadened Raman peak from metallic SWNTs is identified as a Fano line shape, characteristic of coupling of a discrete excitation with a continuum excitation.; The Fano Raman line shape in metallic SWNTs is discovered to show reversible oxidative doping effect. Doping by oxidizing species such as H2SO 4/H2O2, Br2, and NO2 strongly suppresses the Fano Raman line shape, while it recovers after degassing. This sensitivity of metallic Raman line shape is discussed in terms of charge transfer between nanotubes and adsorbed oxidizing species.; Polarized Raman measurements on single SWNT bundles demonstrate that Raman scattering is strongly polarized along the tube axis direction, and all strong Raman active modes behave as A1g. |
