Exploitation of the Fiber Capacity in Optically Amplified Transmission Systems

Abstract As is well known, single-mode optical fibers have a huge optical bandwidth but the exploitation of this optical ether for optical transmission systems is limited by several degrading effects that are present both in the fiber and in other devices composing the link. However, in recent years several techniques have been proposed and tested to show how the system capacity can approach total exploitation of the fiber bandwidth. In this work we survey the main optically amplified communication systems that have been proposed to achieve very-high-capacity transmission and analyze their performances by means of numerical simulations. Numerical simulation is a fundamental tool for the study of optical communication because analytical theories are not able to take into consideration all the effects that are simultaneously present in a real link. The study reports a comparison among the performance of digital intensity modulation systems with direct detection considering both the non-return-to-zero and the return-to-zero (soliton) format, as well as the time and wavelength division multiplexing techniques. The results show how exploitation of the Kerr nonlinearity, use of the in-line filtering process, and introduction of dispersion management are the best means to limit the degrading effects of chromatic dispersion and ASE noise.