Disclosed is a segmented core optical waveguide fiber having low total dispersion slope and negative total dispersion over an extended wavelength window. A wavelength window of particular interest is that in the range of about 1500 nm to 1600 nm. The waveguide fibers in accordance with the invention also have cabled cut off wavelength below about 1480 nm and attenuation at 1550 nm of less than 0.22 dB/km. Mode field diameter is maintained essentially at the nominal value for dispersion shifted waveguide fiber, i.e., 7.7 &mgr;m to 8.7 &mgr;m. Embodiments having a center segment and a first and a second annular segment are discussed in detail.