Abstract: An optical focusing and collecting system includes: a first optical shaping portion, including an output surface, adapted to supply a primary light beam which is made annular; a second optical focusing and collecting portion, including a conical upper central reflective surface and a conical lower central reflective surface; a third optical return portion, including a reflective surface located between the output surface and the upper central reflective surface, along a main optical axis (?) and having transverse dimensions smaller than those of the annular primary light beam supplied by the first optical portion.