Testbed for WDM field trials over 750 km with full compensation of chromatic dispersion

Optical transmission is mainly influenced by attenuation, chromatic dispersion, nonlinearities and polarization mode dispersion of the fibre. For repeater-free high speed and long haul WDM transmission systems a broadband compensation of chromatic dispersion is required. One of the most effective methods to perform this, is the use of dispersion compensating fibres (DCF) 4×2.5 Gbit/s field transmission experiments were demonstrated over 135 km and a single channel transmission over 4000 km was performed in a recirculating loop testbed. A replica of the Berlin-Darmstadt field transmission line was realized in a laboratory experiment and four 2.5 Gbit/s WDM channels with directly modulated transmitter lasers were transmitted over 750 km. We present the results of field installation of four WDM channels on the Berlin-Darmstadt fibre link, with full dispersion compensation. The link is transparent for all applied data rates up to 10 Gbit/s and wavelengths in the amplifying bandwidth of fibre amplifiers. A 1.3 μm supervisory channel was installed and processed by a line service unit within the fibre amplifiers (EDFA). The link is designed for test applications of commercially available WDM-systems and components