Nonlinear Shannon limit in pseudo-linear coherent systems
15 June 2012
Abstractâ"In this paper, we develop the most general first-order perturbation theory of the propagation of a signal in an optical fiber in the presence of amplification and Kerr nonlinearity, valid for arbitrary pulse shapes. We obtain a general expression of the sampled signal after optical filtering, coherent detection and optimal sampling. We include intra-channel and as well as inter-channel effects. We obtain simplified expressions in the case in which the accumulated dispersion is high (equivalent to the farfield limit in paraxial optics). This general theory is applied in detail to the spacial case of sinc pulses. This exercise show that the side channel characteristics are essential in determining the nonlinear impairments.
