Encyclopedia of Modern Optics

The breakthrough of optical amplification, combined with the techniques of wavelength division multiplexing (WDM) and dispersion management, have made it possible to exploit a sizeable fraction of the optical fiber bandwidth (several terahertz). Systems based on 10 Gbit/s per channel bit-rate and showing capacities of several terabit/s, with transmission capabilities of hundreds or even thousands of kilometers, have reached the commercial area.