6 |
Optical Pulse Amplification |
6.1 INTRODUCTION
In an early stage, the ultimate capacity limits of optic-optic communication systems were determined by the spectral bandwidth of the signal source and of the fundamental fiber parameters: loss and dispersion. However, in the mid-1980s of the last century, the international development had reached a state at which not only dispersion-shifted fibers but also spectrally pure signal sources were available. In such circumstances, the remaining limitations for long-haul lightwave systems by that time were imposed by fiber loss. These limitations have traditionally been overcome by periodic regeneration of the optical signals at repeaters applying conversion to an intermediate electric signal. ...
