Abstract : Optical properties of single-walled carbon nanotubes show strong signatures of one-dimensionnal confinement. As a matter of fact, all optical transitions arise from strongly bound excitons. In this thesis, we report on the study of the fine structure of these excitons by means of photoluminescence and Rayleigh scattering spectroscopies. The dynamics of these excitons is also investigated on a sub-picosecond time-scale and brings evidence for the tremendous influence of the environment on the optical properties of such nano-objects for which all constitutive atoms lie on the surface. In a last part, we show how to take advantage of this interaction with the environment. We study nanotubes functionnalized by organic dyes intended to implement light-harvesting functions in new opto-electronic devices.