High resolution optical methods overcome the diraction limit, a step essential for understanding
the physical and chemical properties of nanostructures. In this work, I applied tip-enhanced
near-eld optical microscopy (TENOM) to study the optical properties of single-wall carbon nanotubes
(SWNTs) with nanoscale spatial resolution. Simultaneously obtained near-eld Raman
scattering and photoluminescence (PL) data is shown to provide information with unprecedented
detail on the nanotube structure and the resulting phonon and exciton properties. Near-eld PL
is found to be more localized along single nanotubes than Raman scattering in most cases due
to defects and environmental perturbations. By detecting near-eld PL spectra, my work has
shown exciton energy variations along the same nanotubes induced by the environment. The
local PL energy response to DNA-wrapping reveals large DNA-induced redshifts of the exciton
energy that are two times higher than indicated by spatially averaging confocal microscopy. Exciton
energy transfer between two semiconducting nanotubes is observed for the rst time limited
to small distances because of competing fast non-radiative relaxation. The transfer mechanism
is explained by F�orster-type electromagnetic near-eld coupling. In addition, towards the end
of a nanotube, PL decay is observed on a length scale of 15-40 nm which is attributed to exciton
propagation followed by additional non-radiative relaxation at the nanotube end. The dierent
enhancement mechanisms of Raman scattering and PL lead to dierent enhancement factors of
the two signals. The PL enhancement can be stronger than the Raman enhancement because of
the very low initial quantum yield of nanotubes. The signal enhancement of Raman scattering
and PL is also found to exhibit dierent tip-sample distance dependencies because of the PL
quenching eects from the gold tip. The results achieved in my thesis highlight the enormous
capabilities of TENOM for the investigation of nanoscale surfaces