Résumé
We review the main information that we have obtained from Raman spectroscopy experiments combined with electron diffraction experiments on individual freestanding single-walled carbon nanotubes. This information concerns: the radial breathing mode vs diameter relationship; the dependence of the frequency and lineshape of the G-modes in semi conducting and metallic tubes; the evaluation of the optical transition energies for individual freestanding SWNTs. These experimental Raman results obtained on index-identified individual SWNTs are compared with other experimental data and theoretical predictions. The intrinsic lineshape of G-modes of the achiral and chiral semi conducting and metallic SWNTs are unambiguously established. The results also support the fact that non adiabatic effect should be taken into account to describe the diameter dependence of the LO modes of metallic SWNT. From these data, we can also define Raman criteria that allow identifying carbon nanotubes from their Raman features only. We show the efficiency of this approach: (i) to assign the (n,m) indices of individual freestanding single-walled carbon nanotubes, and (ii) to identify the (n,m) tubes organized in a small bundle.