Information Capacity of Nonlinear WDM Fiber Optical Transmission Line

We propose a phenomenological model for a WDM fiber optic transmission system. In determining the information capacity of this nonlinear WDM transmission system, interchannel interference is modeled as multiplicative Gaussian noise. We quantify the extent to which the information capacity is reducted below the Shannon capacity of a corresponding linearized optical transmission line. We conjecture that for systems of practical interest, the nonlinear effect, as modeled here, serve to express the fundamental limitations on the spectral efficiency of optical data transmission.