Average soliton dynamics and the operation of soliton systems with lumped amplifiers

It is shown that the dynamics of optical pulse propagation in lumped amplified systems is described by the lossless nonlinear Schrodinger equation under the condition that the amplifier spacing is short compared to the nonlinear evolution length scale. The errors involved in this description are quantified and are on the order of the square of the amplifier spacing. The authors also consider an alternative method of pulse preemphasis which has been proposed, and they show how it relates to the average soliton method presented.<>