What is Solitons

The authors solve the propagation soliton perturbation problem in a nonlinear optical system based on a single mode optical fiber by introducing Rayleigh's dissipation function in the framework of variational approach. The adopted methodology has facilitated the variational approach to be applied on a dissipative system where the Lagrangian and Hamiltonian are difficult to solve. The authors model the propagation in a nonlinear medium by using a nonlinear Schrödinger equation (NLSE). This is a mathematical model used to describe the optical fiber. The chapter is focused on the propagation of perturbed solitary waves in single mode fiber.