Optical amplifiers to enhance performance of optical communication systems

The decisive measure of the worth of any communications medium is its transmissionperformance, which at the most fundamental level is measured by the signal loss through afinite length of a channel, and the bandwidth limiting effects which constrain the capacityof the channel. The solution of these problems is direct optical amplification. Nonlinearityeffects arose as optical fiber data rates, transmission lengths, number of wavelengths, andoptical power levels increased.Optical amplifiers have a strong effect on the performance and design of opticalnetworks resulting in the deployment of a large number of high capacity long distanceoptical transmission systems. In fact, the finest amplification span length is one thatfacilitates the best trade-off between low cost requirements - a low number of amplifiers,ensuring cost efficiency- and stringent system performance constraints - a large number ofamplifiers ensuring good performance of transmission system because of the reduction ofaccumulated amplified spontaneous emission (ASE) noise.