ABSTRACT
This chapter reviews the relevant properties of the fiber-optical transmission line as a nonlinear communication channel. It is devoted to the calculation of the fundamental limit to the information capacity of such a channel. The chapter deals with the actual information capacity corresponding to existing coherent and incoherent formats and introduces a novel approach to optical code-division multiple access (OCDMA) codes with improved performance. It considers the limits on the information capacity of fiber-optical CDMA systems. The chapter demonstrates that the fiber nonlinearity leads to the deterioration of the information capacity, and developed the theory of this effect. It reviews the properties of the signal propagation in fiber-optical systems, and the relevant concepts from information theory that describe information transmission in such communication channels. The chapter also considers a typical fiber-optical communication system, which consists of a sequence of N fibers each followed by an amplifier.
