8 x 10 Gb/s 1.3-μm unrepeatered transmission over a distance of 141 km with Raman post- and pre-amplifiers

A repeaterless wavelength-division-multiplexed transmission system operating in the 1.3-μm wavelength window is demonstrated by means of discrete Raman fiber amplifiers. The power budget is 45.1 dB, leaving a margin of 1.6 dB for a transmission distance of 141 km. The eight channels, which occupy a wavelength range from 1305.8 to 1311.6 nm, carry data at a rate of 10 Gb/s each. The Raman post- and pre-amplifier both employ a two-stage ring topology, which allows counterpropagating pumping.