9 |
Optical Regeneration |
9.1 INTRODUCTION
Optical signals propagating in fiber-optic transmission systems are affected by several effects, namely amplified spontaneous emission (ASE) from optical amplifiers, chromatic dispersion, polarization-mode dispersion, and nonlinear phenomena. Considering the impairments imposed by these effects, the use of signal regenerators becomes necessary in order to extend the maximum transmission distance of the systems. Devices that perform the reamplification, reshaping, and retiming of the degraded bit stream are called 3R regenerators, whereas those able to perform only the first two functions are called 2R regenerators.
The signal regeneration is conventionally performed by optical-electrical-optical ...
