| Contents |
| The evolution of the optical signal in fiber is described by Nonlinear Schr\"odinger Equation (NLSE) which can be solved by means of Inverse Scattering Transformation formalism. In the eigenvalue communication paradigm, where data are mapped on the spectral parameters of the signal, the fiber channel capacity has to be evaluated using the statistical characteristics of the spectrum of the Zakharov-Shabat operator, the underlying linear operator of the NLSE. Approximating the operator by a large matrix, we can use the Green's function to calculate the spectral density i.e. the density of eigenvalues of the operator. Since the operator in not self-adjoint (non-hermitian matrix) the conventional diagramatic methods of finding the Green's function can not be applied.
Here we try to use some recently proposed methods of dealing with non-hermitian matrices such as Generalized Green's function for the problem of evaluating the capacity of optical fiber in the presence of ASE noise (non-distributed additive noise) considering the noise as the random part of the operator. |
|