Theoretical calculations supported by numerical simulations show that utilization of the nonlinear dependence of the index of refraction on intensity makes possible the transmission of picosecond optical pulses without distortion in dielectric fiber waveguides with group velocity dispersion. In the case of normal dispersion (∂2&ohgr;/∂k2< 0) discussed here [the case of anomalous dispersion (∂2&ohgr;/∂k2> 0) was discussed in an earlier letter], the stationary pulse is a ``dark'' pulse or envelope shock. Numerical simulations show that such pulses are stable under the influence of small perturbations, white noise, or absorption. Important considerations relating to the practical applications of both ``bright'' and ``dark'' pulses are also discussed.