A 90-Mb/s transmission experiment in single-mode fibers using 1.5-µm multi-longitudinal- mode InAsGaP/InP lasers

Transmission at 90 Mb/s in single-mode fibers using 1.5-μm multi-longitudinal-mode InAsGaP/InP lasers was studied for fiber lengths of up to 82 km. An empirical formula has been developed that relates the bit rate and distance for a dispersion-limited system. The effects of intersymbol interference (ISI) and mode-partition noise (MPN) are analyzed empirically, and are compared to existing theories. The results indicate that for the specific lasers used (rms spectral width ≈ 2 nm), fiber dispersion and mode partition noise would limit the span length for a practical system to approximately 50 km.