The use of optics to address nanoscience is the use of a huge probe to sense a tiny material. This happens because, in the visible, light is associated with wavelengths in the range of hundreds of nanometers to microns. However, nanotechnology offers some techniques to overcome this limitation, such as exploring resonance phenomena playing against the very low efficiency of a single nanostructure, or using plasmonics to localize light into nanometer sized areas. In this talk I will discuss these aspects of nanoscale photo-physics, addressing the evolution of Raman spectroscopy applied on carbon nanostructures. Carbon nanotubes, graphene and amorphous carbons are prototypes for the development of nanometrology due to their unique mechanical and electronic structures, and applications in cross-related fields, such as biomedicine and soil science demonstrate the power of the technique