An optical waveguide fiber having a core surrounded by a cladding. The
core may have only a central segment, or a central segment and an annular
segment surrounding the central segment. The central segment has a
positive relative refractive index profile. The annular segment has a
negative relative refractive index profile. The relative refractive index
of the optical fiber provides an LP02 cable cutoff less than 850 nm and
an LP21 cable cutoff less than 850 nm.