An optical waveguide fiber having a zero-dispersion wavelength less than 1450 nm, a dispersion slope at a wavelength of 1550 of less than 0.06 ps/nm.sup.2/km nm, and attenuation at a wavelength of 1550 nm less than 0.190 dB/km. Optical fibers are disclosed that exhibit an effective area at a wavelength of 1550 nm of greater than 50 .mu.m.sup.2, and dispersion at a wavelength of 1550 nm between 5 and 15 ps/nm-km.