Achieving a multi-Gbit/s optical transmission system in the 1.5-μm wavelength region with a dispersion-shifted fiber' is important for high-capacity long-span transmissions because of the lower fiber loss and smaller fiber dispersion. However, in multi-Gbit/s systems, even the smaller fiber dispersion distorts the pulse waveforms and degrades the sensitivity after transmission. In our experiment, first the allowable fiber dispersion for multi-Gbit/s systems is obtained through several multi-Gbit/s transmission experiments over a 100-km span. Next, it is shown that the allowable fiber dispersion was determined by DFB LD subpeak spectra, which were observed at the leading edge of the pulse.
© 1988 Optical Society of AmericaPDF Article