An optical fiber has three or four core slices including one or more buried slices
and a raised central slice. The buried slice or each of the buried slices is very
deeply buried. The fiber has a zero dispersion wavelength of less than 1 460 nm.
It has a chromatic dispersion in the vicinity of 5 ps/nm.km and a dispersion slope
in the vicinity of 0.03 ps/nm2.km at a wavelength of 1 550 nm.
