10-Gb/s standard fiber transmission using directly modulated 1.55-μm quantum-well DFB lasers

10-Gb/s long-haul transmission on standard single-mode fibers at 1.55 μm with intensity modulated, low-chirp MQW DFB lasers is investigated. Successful transmission is achieved by operating the laser at increased bias. Thus, the laser chirp acts favorably on the propagation after an initial distance of 30 km in the fiber. A detailed system evaluation with an optical preamplified PIN-receiver, reveals a negligible dispersion power penalty for transmission distances between 35 and 70 km. The power penalty, mainly caused by a lower extinction ratio, must be accepted.