Abstract

In fiber optic networks, the number of wavelength channels and the bit rate per wavelength channel determine the transmission capacity. In the past, the bit rate per wavelength channel (TDM or Time Division Multiplexing bit rate) of installed fibre transmission systems was steadily increased e.g. to 2.5 Gbit/s in about 1990 and to 40 Gbit/s presently. TDM may be realized by electrical multiplexing (ETDM) or by optical multiplexing (OTDM) to a high speed data signal. The installed 40 Gbit/s systems use ETDM and in laboratories the first 100 Gbit/s ETDM-experiments have been performed. On the other hand, at the same data rates, OTDM transmission experiments have been carried out about 10 years earlier. For instance, the first 100 Gbit/s OTDM transmission experiment over a 36 km fiber link was reported already in 1993. Since then, OTDM transmission technologies have been made a lot of progress towards much higher bit rates and much longer transmission links. For example in this paper, we will report on 160 Gbit/s transmission over a record length of 4320 km and on 2.56 Tbit/s transmission over 160 km.

© 2007 IEEE