Transmission over 560 km at 2.5 Gb/s using a directly modulated buried heterostructure gain-coupled DFB semiconductor laser

We have developed a buried heterostructure gain-coupled DFB laser capable of 2.5 Gb/s transmission up to 560 km of standard single mode fibre with a dispersion penalty less than 2 dB. Low dispersion penalty is also observed when using low frequency content SONET section overhead bytes and we believe this is made possible by the low thermal chirp characteristics of the device. The reach capability of this device also enables simplified and low cost manufacture because the use of a generic design for multiple reach requirements is made possible.